|Chemical composition %||Digestibility coefficientley %|
|Digestible crude protein||-||10.7|
|Total digestible Nutrients||-||52.6|
Seventeen collections of which belong to Dolichos lablab var. lignosus and eight of Dolichos lablab var. typicus comprised the material for the study. Among them twelve were received from United States and one from Hungary and four were local collections.
|Collections||Mean percentage of protein||Collections||Mean percentage of protein|
|Var. lignosus||Var. typicus|
|Local field bean (light bown)||22.56±0.195||Local garden type||21.38±0.001|
|Local field bean (deep brown)||22.84±0.002||US 67-39||20.90±0.195|
|Local field bean (white)||20.90±0.001||US 67-33||US 67-33|
|US 67-43||24.78±0.001||US 67-24||23.81±0.195|
|US 67-49||26.73±0.001||US 67-32||19.44±0.001|
|US 67-29||27.94±0.440||US 67-25||22.37±0.001|
|US 67-13||29.16±0.002||US 67-10||26.24±0.001|
There is considerable variation in the composition of the pods and the seeds of the hyacinth bean according to cultivar, climatic conditions and the standard of crop management. The proportion of seed to pod-husk is approximately 1.1:1. The approximate composition of the immature pods has been given as: moisture-82.4%; protein-4.5%; fat-0.1%; fibre-2%; carbohydrate-10%; ash-1%, calcium-0.05%; phosphorus-0.06%; iron-10 mg / 100g and nicotinic acid-0.8 mg / 100g: Vitamin C: uncooked samples-0.77-1.12 mg / 100 g and cooked samples-7.33-10.26 mg / 100 g. (The increase in Vitamin C content on cooking is attributed to the softening of the internal tissues, which facilitate extraction). The protein content of the mature seeds normally varies between 21-29%. American cultivars, when grown in India, have a high protein content, but are less vigorous and lower yielding than local varieties. An approximate analysis of dry, fully ripe Indian seeds have been given as: moisture-9.6% protein-24.9%; fat-0.8%; fibre-1.4%; carbohydrate-60.1%; ash-3.2%; calcium-0.06%; phosphorus-0.45%; iron-2 mg /100g and nicotinic acid-1.8 mg / 100 g.
The chief protein is a globulin and Dolichosin. The amino acid content (mg / g N) has been reported as: isolencine-256, leucine-436, lycine-36, methionine-36, cystine-57, phenyl alanine-299, tyrosine-197, threonine-207, valine-294, arginine-393, histidine-186, alanine-266, aspartic acid-727, glutemic acid-978, proline-288 and serine-323.
Infestation with bruchid beetles has been found to decrease the thiamine and methionine content significantly. The seed contains from 38.6 to 46% starch on a dry weight basis. It has an iodine value of 6.05, corresponding to approximately 30% amylase.
The hyacinth bean is a rich source of catechol oxidase. The presence of a cyanogenic glycoside has been reported in certain cultivars. Two haemagglutinins have been isolated from meal prepared from the beans and one of these has been found to cause zonal necrosis of the liver when fed to rats.
A radioimmunoassay, capable of detecting the Dolichos biflorus lectin at concentrations as low as 400 ng/ml, was developed and used to follow the distribution of this lectin in the plant during its life cycle. The lectin was first detected in the seeds of the plant 27 days after flowering and rapidly attained the high level of lectin present in the mature seed. The lectin content of the plant is highest in the seeds and cotyledons and decreases as the storage materials of the cotyledons decrease. A low but measurable amount of material that reacts with antibodies to the seed lectin was detected in the leaves, stems, and pods of the plant. This material gives a precipitin band of only partial identity to the seed lectin when tested in immunodiffusion against antiserum to the seed lectin. No lectin was detected by the radioimmunoassay in the roots of the plant at any stage of development.
Some of the varieties of Dolichos lablab secrete some fragrant oil on the surface of the pods. When it is used as a vegetable, Indian consumer shows preference for varieties with fragrant oil. Preliminary observations indicated that the exudates, even in the low concentration, attract the important insect pest of this crop, Adisura atkinsoni, whose life cycle appears to depend upon the life cycle of the field bean plant
The gas chromatographic-mass spectrometric (GC-MS) analyses were performed on a Finningan 3200 E automated GC-MS instrument using a 1.52 m 3% OV-17 on Su pelcopart 60 /80 column with temperature programmed at 120 / min from 50-300°C. To establish the identities of the compounds in the exudate, GC-MS of the authentic samples were run under the same instrumental conditions. The details of the preparations and the methods of estimation, etc. have been described in the paper and based on the results, conclusions are drawn.
The interesting and noteworthy features of the Dolichos lablab pod exudates are: (1) The occurrence of continuous series of homologues of odd and even numbered straight carbon chain fatty acids from C-11 through C-24 without any omissions. (2) Almost all saturated acids in the series occur both as free acids and as their methyl esters. (3) Most of the saturated acids are followed by their a1- b unsaturated analogues, which occur mainly as free acids. (4) The major constituents of the mixture are trans-2- dodecenoic acid and trans-2- tetradecenoic acid. Though trans-∆2- enoic acids are found in nature, such concentrations of them and so many homologues as found in the present case are notably unusual. It is also be recognized that the most common and widely distributed olefinic acids in natural fats like oleic, linolenic, palmitoleic, etc. acids are absent in the exudates. (5) The exudates probably contain some small amounts of ghycerides since the glycerol could be identified as its TMSO derivative after saponification of the exudate. However, the nature of these glycerides was not established.
The function of the exudate in the life of the field bean plant is not known. It could be just an end product of the metabolic process, or it may be playing some other ecological role. However, it was possible to record here that it might act as an attractant for the insect pests of this crop under laboratory conditions. It was noted that the exudate acts as a bactericide or bacteristat which is in conformity with the earlier observations that fatty acids and their derivatives do posses such properties. Therefore, it is a speculation that the exudate plays an ecologically important role and an understanding of its nature would perhaps be helpful in the pest management of the field bean crop.
Samples of freeze-dried green field bean (Dolichos lablab) and dry mature bean were subjected to some processing methods: heat processing, extraction with 80% ethanol, hexane or dilute acid, protein isolation, and these samples were evaluated for growth-promoting value and toxicity. Extraction with 80% ethanol or with dilute acid increased survival period of the animals; but these did not promote growth. Heat- processing was essential to destroy antinutritional factors and promote growth. Extraction of the beans with 80% ethanol did not, however, alter the trypsin inhibitor or haemagglutinin activities. The protein isolate and acid-extracted residue which had low trypsin inhibitor and haemagglutinin activities did not also promote growth. Thus the trypsin inhibitor and haemagglutinin did not completely account for the toxicity to albino rats. However, heat processing of ethanol extracted bean flour indicated that the beneficial effect of ethanol extraction was not apparent once the samples were heat processed. Dry mature bean dhal was more toxic than the whole bean either dry or green. Supplementation of heat processed field bean with methionine and tryptophan promoted good growth of albino rats and significantly increased the protein efficiency ratio.
The lectin of the Indian bean or Lablab (Dolichos lablab L.) was purified by affinity chromatography on two types of affinity carriers: O-a-D-mannopyranosyl-Separon and Separon-bound ovomucoid. The lectin is homogeneous in the ultracentrifuge: s2O, w= 6.14S, Mr= 110000; the molecule appears to comprise two pairs of two types of subunits (Mr 16000 and 40000), and contains 2% neutral sugar and 0.2 Mn and 0.5 Zn atom respectively. The lectin agglutinates human erythrocytes non-specifically with regard to ABO grouping at a limit concentration of 8,ug/ml, and this activity is inhibited most effectively by N-acetyl-D-glucosamine, methyl a-D-mannopyranoside and ovomucoid, but not by free D-mannose.
The lectins from the seeds of Dolichos lablab var. lignosus (field bean) and Dolichos lablab var. typicus (Lablab bean) have been isolated in a homogeneous form by affinity chromatography on D-mannose linked Sepharose. Both the lectins are glycoproteins and have a molecular weight of 60,000 and S 20,w value of 52 and seem to be made up of 4 similar subunits (apparent molecular weight 15,000). The carbohydrate content ofthe lectins is mostly fucose (2-5 mol per mol of protein), mannose (5-8 mol per mol of protein) and N-acetyl glucosamine (1-2 mol per mol of protein). The amino acid composition of both the lectins was similar and methionine and half cystine could not be detected, Both the lectins have similar tryptic peptide map. Alanine and serine were the only Ν and C-terminal amino acids for both lectins. The lectins were found to contain low amounts of bound metals such as manganese, magnesium and calcium. The near ultra-violet circular dichroism spectra of the lectins are similar to that of Sainfoin. Circular dichroism data indicate that tyrosine and tryptophan residues are involved in sugar binding. The lectins are nonspecific for human blood groups and they agglutinate a variety of other erythrocytes. Among a number of sugars, D-glucose and D-mannose.
24 crossbred cows (75% Holstein/ 25% Zebu) grazed for 4 h/day at 2.3 cows/ha and 6 wethers were given silage of Panicum maximum cv. Likoni alone or with fresh L. purpureus offered at 30% of the ration. DM intake, DM digestibility and OM intake by sheep were improved with the inclusion of the legume. Milk production was significantly higher than without legume (10.7 and 9.2 kg/cow/day, respectively) and the DM intake improved (5.8 and 4.8 kg/cow/day with and without legume, respectively). Inclusion of legume saved 1.2 kg concentrate/cow/day. It was concluded that this legume may be used with silage diets during the dry season in order to obtain milk production of 10 kg/cow/day.
The stigma of L. purpureus was wet and papillate. The secretion of the exudate started at the tip of the stigma 4 days before anthesis. It was maximum at the time of pollination after which it decreased gradually. The exudates consisted of unsaturated lipids, reducing acids, proteins, phenols, insoluble polysaccharides and alkaloids. It plays a variety of roles including the protection of the stigma from desiccation and chewing insects.
Hundred grams of dried seeds contain 12.1% moisture, 21.5g protein, 1.2 g fat, 61.4g carbohydrate, 6.8 g fibre, 3.8 g ash, 98 mg Ca, 345 mg P, 3.9 mg Fe and 334 calories.
Raw green pods contain in 100 g edible portion, 87.5% moisture. 3.1 g protein, 0.3 g fat, 8.2 g total carbohydrates, 1.9 g fibre, 0.9g ash, 75 mg Ca, 50 mg P, 1.2 mg Fe, 2 mg Na, 275 mg K, 160 mg carotene equivalent, 0.08 mg thiamine, 0.13 mg riboflavin, 0.60 mg niocin, 16 mg ascorbic acid and 30 calories.
Hundred grams raw leaves contain 31 calories, 89.1% water, 2.4 g protein, 0.4 g fat, 6.1 g carbohydrate, 6.7 g fibre, 1.4 g ash, 120 mg Ca, 57 mg P, 17 mg Fe, 3145 mg carotene equivalent, 0.28 mg thiamine and 16 mg ascorbic acid.
Raw runners contain in 100 g: 33 calories, 86% moisture, 2.8 g protein, 0.2 g fat, 6.8 g total carbohydrate, 1.4 g fibre, 0.6 g ash, 116 mg Ca, 63 mg P, 1.5 mg Fe and 268 mg K.
Dried seeds contain 0.15 mg pyridoxine, 1.2 mg pantothenic acid, 0 µg vitamin B12 and 21.8 µg folic acid.
Vitamin C content of raw pods varies from 7.33 to 10.26 mg / 100g, cooked pods 0.77-1.12 mg/100g (assuming WOI had the values mixed).
For seed yielding 23.4 g protein and 1.1% oil, the amino acids per 16 g N were: 6-8 g lysine, 0.9 g methionine, 6.6 g arginic, 4.6 g glycine, 3.2g histidine, 4.4 g isoleucine, 8.5g leucine, 4.9 g phenylalanine, 3.6 g tyrosine, 4.2 g threonine, 5.2 g valine, 4.5 g alanine, 12.0 g aspartic acid, 15.7 g glutemic acid, 0.6 g hydroxy proline, 4.3 g proline and 5.4g serine
Forage composition is 28.1% fibre, 3.5% fat, 14.2% crude protein, 39.4% carbohydrate, 14.8% ash, 1.98% Ca, and 0.26% P. Dry feed has 28.08% fibre, 3.5% ether extract, 14.8% total ash, 2.77% Cao, 0.6% P2O5, 0.97% MgO, 0.55% N2O and 3.52% K2O.
Seeds contain trypsin inhibitors and chymotrypsin inhibitors and may contain cyanide and stigma sterol. It is said to be a rich source of catechol oxidase.
Nitrate reductase activity in the leaves at the flowering stage showed a variability range from 25.04 to 42.50 mM KNO3 reduced/g freshweight per hour. The corresponding values of protein in the leaves ranged from 2.83 to 4.32%. Genotype FD-1 showed the highest NRA and also the highest protein value, whereas the lowest value was obtained in L-20. Similar results were also obtained in edible immature pods where NRA varied from 19.38 to 32.33 mM KNO3 reduced / g freshweight per hour. The maximum (6.49%) and minimum (4.53%) protein values coincided with the genotypes showing highest (FD-1) and lowest (L-20) NRA in particular. There was highly significant positive correlation (r = 0.906) between leaf protein content and the activity of the enzyme in leaves.
Nitrate reductase activity in edible immature pods was investigated to see the varietal behaviour of NRA vis a vis protein accumulation pattern in developing pods. It was observed that the genotypes behaved differently in respect of their NRA and also in the pod protein deposition. Highly significant positive correlation between protein content and the enzyme activity in developing pods was observed (r = 0872).
Sufficient NRA in the developing pods indicated that during pod per seed development, not all but a portion of unreduced-N is translocated to seeds from the leaves and a sizeable protein has got to be reduced in situ. Therefore, measurement of NRA during flowering as well as pod or seed development stage is an important consideration in total protein harvest of the pod per seed. The differential behaviour of cultivars in respect of NRA indicated that enzyme activity might play a regulatory role in the sum of reduced-N and the peak of genetic performance might be attained only if the supply of raw material from soil is not limiting.
In this study, the mature seeds of five cultivars were analyzed for some nutritional and antinutironal factors. The cultivars showed considerable variation in composition. On a dry matter basis, the percentage of crude protein varied from 22.4 to 31.3, crude fiber from 7.62 to 9.63 and total carbohydrate from 54.2 to 63.3. The amounts of Ca, P, phytate-P and Fe ranged from 36.0 to 53.5, 388 to 483, 282 to 380 and 5.95 to 6.90mg/100g respectively. All cultivars tested contained moderately high levels of trypsin inhibitor activity. Phytic acid and tannin contents varied from 1000 to 1350 and 2000 to 2205 mg/g, respectively.
In experiment-1, 25 goats were fed for 42 days on a diet of 50% hay and 50% oat straw and minerals given to apetite (T1) or supplemented with L. purpureus 3 (T2), 6 (T3) or 12/ kg live weight (T4), or air-dry lupin grain 12 g/kg live weight (T5). Roughage intake and live weight gain were lower for T4 (390 and 32 g/day) than for the other treatments, but organic matter digestibility was higher for T4 and T5 than for T1. In experiment 2, rumen-cannulated Merino lambs, body weight 18-31 kg were fed on diets containing 50% Oat chaff, 50% barley straw and minerals ad libidumand supplemented with air-dry Lablab grain 5, 10 or 20 g/kg body weight or the same amounts of air - dry lupin grain. In equivalent treatments, intakes of roughage and grain were similar, but digestibility and body weight gain were lower for Lablab than for lupin diets. Wool growth was lower at the highest level of Lablab supplementation.
|Plant part||Protein %||Fat %||Carbon %||Fibre %||Mineral %|
Coloured seeds contain cynogenic glucosides, while the white seeds contain non-toxic amount of this substance
A photochemical investigation for bioactive compounds by thin-layer chromatography using the Marini-Betollo method was conducted on the fresh leaf extracts of Dolichos lablab L. Results showed that the following constituents were detected in the non-polar, semipolar and polar fractions: sugar, higher alcohols, phenols, steroids, essential oils, alkaloids, tannins, flavonoids, saponins, coumarins, and anthnanoids.
A gradual decrease was noted in total protein and albumin, prolamin and glutelin fractional in the endosperm of D. lablab germinated for 8 d. Prodamin showed the greatest decrease of 85%, whereas only 25% decrease was noted in the globulin fraction. Both acid and alkaline protease activities increased during germination; and protease activity was consistently higher than alkaline protease activity throughout. Electrophoretic studies showed that high MW polypeptide bands disappeared with the appearance of new low MW polypeptide bands in the endosperm protein of the germinating seeds. Total phenolics and tannin contents and trypsin inhibitory activity also increased as germination progressed. Germination increased the in vitro protein digestibility of the endosperm by pepsin, trypsin and pancreatin. It showed a negative but non-significant correlation with trypsin inhibitory activity, phenolics and tannin contents. Amylase activity also increased gradually upto the 6th day of germination which coincided with an increase in reducing sugars.
Two hundred Cobb broiler one day old chicken were randomly allocated to five rations containing levels of Dolichos beans (Lablab purpureus) meal at 0, 5, 15, 20 and 25% and soya meal at 25, 20, 10, 5 and 0%. Feed intake, feed utilization efficiency, growth and mortality rates were determined from 2-8 weeks at which time the birds were slaughtered and dressing percentages and organ weights were determined.
As the level of Dolichos bean meal increased, there was a decrease in crude protein and an increase in crude fibre in the diets, but the changes were not significant (P>0.05). Weight gain was highest (28.6 g. 20%) for the ration containing 25% soybean meal and lowest (26.6g/day) for the diet containing 25% Dolichos bean meal. Feed intake was highest for the ration containing 25% Dolichos bean meal. But there was no significant difference (P>0.05) between the treatments. Although the mortality rate was highest (16%) in the diet containing 25% Dolichos bean meal, the beans were well accepted by the birds, and the protein appeared to be well utilized, with a feed: gain ratio of 3.02. The value was only slightly poorer (P>0.05) than that recorded for the diet containing soybean meal (2.78).
Mixed maize/ L. purpureus silage was compared for nutritive value with Panicum maximum cv. Likoni silage using 12 wethers (6/treatment) in metabolism cages (12 days for adaptation and 7 days for data recording). The mixed silage was cut and ensiled when maize was at the milk stage of ripening and P. maximum was ensiled at 65 days growth. DM and OM contents were significantly higher in the mixed silage, as was the nutrient digestibility. The DM intake, digestible OM and metabolizable energy were also significantly higher in the mixed silage, which had a CP content of 13.42%, low CF content (25.5%) and acceptable Ca and P content.
Weather in metabolism cages were used to determine the nutritive value of forage harvested after 60-67 d (sunflowers), 65 - 72 d (Kenaf) and 64-74 d (Lablab purpureus). CP content was 11.6-14.4% in sunflower, 13.1-16.1% in Kenaf and 15.8 - 16.2% in L. purpureus, while OM digestibility was 67-68.9%, 78.9-79.1% and 72.0-72.8%. Metabolizable energy content at 9.8-11.7 Mj/kg DM was considered high. DM intake of sunflower and kenaf (35.3-45.6 g/kg metabolic weight) was low, but intake of L. purpureus (78.2-79.0 g/kg) was acceptable. Analysis of all the indicators showed the nutritive value of L. purpureus to be high and that of kenaf to be adequate, but sunflower had low nutritive value and was not recommended for the conditions of the trial.
Presents results of a study carried out in Tanzania to investigate the effect of inclusion of lablab meal on growth rate, feed intake and carcass composition of Black Head Persian (BHP) lambs. Twenty-four BHP castrate sheep were given randomly to four dietary treatments. Lambs were individually maintained in metabolic crates. All animals were offered hay ad libitum. Animals on (A) were given in addition 380 g of maize bran per day. Animals on treatments B, C, and D were given 380 g of concentrate based on maize bran w. 25, 50 and 75 percent lablab meal respectively. It is concluded that inclusion of lablab meal in maize bran above 25 percent has no beneficial effect in terms of growth rate and carcass composition.
The complete amino acid sequence of two nonidentical subunits of the glucose/mannose-specific lectin from Dolichos lablab (field bean) has been determined by sequential Edman analyses of the intact subunits and peptides derived by enzymatic and chemical cleavage. Peptides were purified by reverse phase high performance liquid chromatography and ion pair chromatography. The D. lablab lectin is a glycoprotein having two polypeptide chains of 132 and 105 amino acid residues. The amino acid sequence of the D. lablab lectin is compared with the various lectins of the family Leguminosae. The D. lablab lectin is the only species of the tribe Phaseoleae that contains two nonidentical subunits of almost equal size and that shows specificity to glucose/ mannose. The lectin shows a greater homology to the glucose/mannose-specific lectins, especially concanavalin A. The unique subunit architecture of the D. lablab lectin indicates the presence of new post translational cleavage sites.
The degradability of cowpea (Vigna unguiculata) and Dolichos lablab (Lablab purpureus) hays (trial-1) and the effect of these legumes on rumen ammonia concentration (RAC), particulate passage rate (Kl) and intake (trial-2) and the degradability of teff (Eragrostis tef) straw (trial - 3) were studied. Trials-1 and 3 were conducted using rumen-cannulated crossbred (Friesian x Boran) cows. In trial-1, cows were freely given native pasture hay plus cotton seed oil meal 2.45 kg/day. In trial-2 calves were freely given teff straw alone or supplemented with cowpea or Lablab hay at 0.5, 1 and 1.5% of body weight. In trial-3, cows were freely given teff straw supplemented with cowpea or Lablab hay at 1% of body weight. Cowpea had similar degradation characteristics to Lablab. Supplementation increased RAC (154-218 vs 48 mg/liter, P<0.01), rate of degradation of teff straw (2.57-2.74 vs 1.38% h; P<0.05), rumen outflow rate (Kl) (1.48-2.09 vs 1.18%h; P<0.05) and decreased mean retention time (MRT; 72.8 vs 109 h; P<0.01). Total DM intake (DMI) increased with increasing supplementation. Cowpea and Lablab had similar RAC rate of degradation of teff straw, Kl, MRT and DMI. It was concluded that both legumes are equally efficient in alleviating nutrient deficiencies incurred when teff straw is fed to calves.
Proteinase inhibitory activity in different varieties of Dolichos lablab L. was determined. All the varieties tested exhibited appreciable level of proteinase inhibitory activity (PIA). The trypsin inhibitory activity (TIA) (Mean: 20170 TI U/g) was relatively higher than the Chymotrypsin inhibitory activity (CIA) (Mean: 15380 CI U/g). Effect of temperature and cooking on PIA was studied. The nature of cooking medium and duration of cooking had profound effect on the PIA. The dry-fried seeds lost their PIA very rapidly (91% in 20 minutes). Seeds cooked in slightly alkaline medium lost their PIA quickly (89% in 30 minutes) compared to those cooked in acidic (80% in 30 min) and neutral pH (83% in 30 min). The PIA in green pods was also determined and they had only one third of the PIA (8200 TI U/g and 8125 CI U/g) found in the dry seeds.
The effect of sowing rate of Lablab purpureus (0, 10, 20 or 30 kg/ha) and the time of sowing in relation to planting of Pennisetum purpureum (0, 10 or 20 days after planting 3 to 5 month old stem pieces at 2.5 t/ha) were studied at a site in Cuba with a ferrallitic soil. The highest yield of L. purpureus (2.53 t DM/ha) was obtained by sowing 20 kg seed/ha simultaneously with planting P. purpureum and its yield dcreased as the intercropping time increased. The highest total dry matter yields (legume + grass) were obtained by sowing L. purpureus 20 days after planting the grass, although the yields of the legume were poor (0.35, 0.43 and 0.41 t DM/ha with sowing rates of 10, 20 and 30 kg seed/ha, respectively). The number of L. purpureus plants/m2 increased with the sowing rate. The height of P. purpureum increased as the period of intercropping lengthened. None of the treatments affected the establishment of P. purpureum, which covered about 89% of the area at the end of the experiment. The highest protein yield (0.96 t/ha) was attained with sowing 20 kg/ha of seed at grass planting.
Effects of soaking, cooking and autoclaving on changes in phytohaemagglutinating activity, phytic acid, hydrogen cyanide (HCN), oligosacharides and In vitro protein digestibility were investigated in seeds of Dolichos lablab var. vulgaris. Both distilled water and NaHCO3 solution soaking and autoclaving significantly reduced the contents of total free phenolics (85-88%) compared to raw seeds. Autoclaving (45 minuets) reduced the content of tannins by upto 72%. Soaking seemed to have limited effect in eliminating phytohaemagglutinting activity, whereas autoclaving (45 minutes) seemed to eliminate the haemagglutinating activity completely. The reduction in content of phytic acid was found to be somewhat greater in distilled water soaking (28%) compared to NaHCO3 solution soaking (22%). Only a limited loss in content of phytic acid was observed under autoclaving (87%) compared to the other process studied. Of the three sugars analysed, soaking reduced the level of verbascose more than that of stachyose and raffinose. Autoclaving reduced the content of oligosaccharides more efficiently (67-86%) than ordinary cooking (53-76%). Autoclaving improved the in vitro protein digestibility (IVPD) significantly (13%). Of all the different water and hydrothermal treatments studied autoclaving seemed to be the most efficient method in improving IVPD and eliminating the antinutrients investigated except phytic acid.
In the field trials in Cuba L. purpureus cv. Rongai sown in early October was harvested in early January when 10% pods had dried or after a further 7, 14, 21, 28, 35 or 42 days. Seed yield was greater after further 14 days (879 kg/ha compared with 496 kg/ha at the first harvesting date), but subsequently declined significantly. Germination percentage of seeds immediately after harvest increased significantly when harvested after a further 28-42 days; but when seeds were stored at low temperatures for 6 months, germination percentage reached 100% for all seed samples. It is recommended that seeds should be harvested 14 days after onset of maturity when ~80% of pods were dry.
A field study was conducted on nodulation, time to flowering, dry matter production and forage nutritive value of 17 Lablab accessions collected from sites between 55 and 6974 m above sea level. There were significant variations in excisable nodulation (range 0-22 nodules/plant), dry matter (DM) yields of leaf (17.1-143.9 g/plant) and stem (15.2-161.2 g/plant) but not in days to first flowering (63-85 days). The mean nitrogen concentration in leaf (4% DM) was twice that in stem (1.9%). Mean neutral detergent fibre (41.8%) and acid detergent fibre (29.6%) concentrations in leaf were 20 percentage units lower than that of stem, whereas the in vitro dry matter digestibility of the leaf (64.4%) was 20 percentage units higher than that of stem. There was little variation in the level of acid detergent lignin between leaf and stem. The concentrations of soluble phenolics and insoluble proanthocyanidins were also slightly higher in leaf than in stem. Overall, accessions 1042, 1089, 1067, 1045 and 1071 were consistently higher yielding, irrespective of the available moisture. They have potential for use as a feed supplement in semi-arid parts of Kenya.
Three forage legumes were harvested at 8 weeks of growth before flowering (pre-anthesis) and analyzed for their chemical constituents after sun-(4 days) or oven - drying (60°C for 48 hours). An experiment was conducted with 3 rumen-fistulated Friesian steers (440 kg live weight) to estimate rumen degradability characteristics of DM in the dried forage legumes using nylon bag techniques. The chemical composition of the legumes showed substantial variations. CP content varied from 225-282 g/kg DM while NDF ranged from 328-452 g/kg DM. ADF ranged from 282-326 g/kg DM. There were no significant differences in acid detergent lignin (ADL), Ca and P content of the legumes. Method of drying had a significant effect on CF, NDF, ADF and ash content. The degradation constant varied significantly from 363-431 g/kg DM while there were no significant differences in the degradation constants a and c. The potential degradable faction a + b, was highest for Lablab (842 g/kg DM), followed by cassia (779 g/kg DM) and siratro (746 g/kg DM). At a passage rate of 2% per hour, the calculated DM degradability differed significantly between 669 and 716 g/kg DM. At higher passage rates of 5 and 8% per hour the effective degradability of the forage legumes did not differ significantly. The drying method had no effect on DM degradability. The results suggest that the 3 forage legumes at pre-anthesis stage of growth have a high protein content which is highly degradable in the rumen to an extent which may meet microbial protein requirements for efficient use of low quality roughages.
|Constituants (per 100 g. edible portion)||Content|
|Vitamin A (IU)||617|
|Ascorbic acid (mg)||9|
Lablab and lupin were investigated as supplements for young sheep. In experiment I, rumen-cannulated sheep were offered low quality roughage ad libidum alone or supplemented with about 5, 10 or 20 g/kg live weight whole lupin or Lablab seed. Rumen ammonia concentrations were increased by each level of both supplements and the increases were greater with lupins than with Lablab. The pH of rumen fluid was decreased by both supplements, particularly when the higher levels were fed. Dry matter of broken seeds of both legume species rapidly disappeared from synthetic fibre bags included in the rumen. Roughage dry matter disappearance from synthetic fibre bags decreased (P< 0.05) when 20g / kg live weight lupins was fed and this level of both supplements reduced (P< 0.05) roughage intake. Total dry matter intake was increased more by Lablab than by lupins, but dry matter and organic matter digestibility tended to be increased to a lesser extent by Lablab. Overall, digestible organic matter intake and live weight-gain were increased to similar extents by both supplements. Wool growth was lower (P< 0.05) with Lablab than lupins, particularly at the highest level of supplementation, suggesting that availability of some amino acids was lower with Lablab supplement. In experiment-II, rumen-cannulated sheep were fed low quality roughage adlibidum and supplemented with about 10 g / kg liveweight of either lupin or Lablab seed. Lectins and protease inhibitors present in the Lablab seed disappeared rapidly from synthetic fibre bags incubated in the rumen. In conclusion, nutritional value of Lablab seed as a supplement for sheep fed low quality roughage was similar to that of lupin seed for liveweight gain, but lower for wool growth.
From the glycoside mixture with adjuvant activity obtained from hyacinth beans seeds of D. lablab (Lablab purpureus), 6 new oleanane type triterpene bisdesmosides (Lablabosides A.F.) were isolated together with chikusetsusaponin IV a. The structures of Lablabosides A, B and C were determined on the basis of chemical and physicochemical evidence as
- 3-0-(alpha-L-rhamnopyranosyl (1->2)-beta D-galactopyranosyl (1->2)-beta-D-glucopyranosiduronic acid)-28-0- (beta D-glucopyranasyl oleonic acid
- 3 - 0 (alpha - L. rhamnopyranosyl (1->2) (1->2) - beta - D-glucopyranosiduromic acid)-28-0- (beta-D-glucopyranosyl) 24-epi-hederagenin
- 3-0-(alpha-L-rhamnopyranosyl (1->2)-beta-D- gala etopyranosyl (1->2) beta - glucopyranosiduronic acid) - D- 28-0-(alpha-L-rhamnopyranosyl (1->2)-beta-D-glucopyranosyl) 24-epi- hederagenin.
Seeds of Lablab purpureus grown in Al-Gassim region of Saudi Arabia contains substantial amounts of potassium and low contents of calcium, iron and zinc. Amino-acid composition revealed high contents of glutamic acid, aspartic acid, leucine and lysines. Fatty acid profiles showed the oils composed of 24.2% saturated fatty acid, 18.42% monounsaturated fatty acid and 57.38% polyunsaturated fatty acid with linoleic acid (44%) dominating the fatty acid composition. Anti-nutritional study showed a low content of trypsin inhibitor, phytate and tannin in comparison to other legumes. In vitro digestibility of the bean protein revealed high value (83.78%). The protein solubility at different pH exhibited higher solubility at alkaline pH than acidic one with minimum solubility profie at pH 4.0, which seems to be the isoelectric point.
A proteinase inhibitor resembling Bowman-Birk family inhibitors has been purified from the seeds of cultivar HA-3 of Dolichos lablab perpureus L. The protein was apparently homogeneous as judged by SDS-PAGE, PAGE, IEF, and immunodiffusion. The inhibitor had 12 mole% 1/2-cystine and a few aromatic amino acids, and lacks tryptophan. Field bean proteinase inhibitor (FBPI) exhibited a pI of 4.3 and an Mrof 18,500 Da. CD spectral studies showed random coiled secondary structure. Conformational changes were detected in the FBPI-trypsin/chymotrypsin complexes by difference spectral studies. Apparent Ka values of complexes of inhibitor with trypsin and chymotrypsin were 2.1 × 107 M-1 and 3.1 × 107 M-1, respectively. The binary and ternary complexes of FBPI with trypsin and chymotrypsin have been isolated indicating 1:1 stoichiometry with independent sites for cognate enzymes. Amino acid modification studies showed lysine and tyrosine at the reactive sites of FBPI for trypsin and chymotrypsin, respectively.
The performance of Lablab purpureus for the production of leaf protein concentrates (LPC) during the flowering period (10 - 13 weeks) was studied using a random block design with 4 replications. The legume was sown in red ferrallitic soil and cut 10-13 weeks after germination. Protein extraction was carried out at pH 4.5 and 85°C. The highest forage, LPC and fibrous residue yield were found after cutting 12 and 13 weeks after germination. Forage production reached 7.92 tonnes DM/ha with 16.28% of crude protein. The LPC yield was 385.11 kg DM/ha contributing 44.07% CP and that of the fibrous residues was of 5.24 tonnes DM/ha with 16.09% CP at 13 weeks. The CP percentage extracted did not vary during this period. It is concluded that 12 and 13 weeks should be used for the production of LPC in this species.
The mannose/glucose -binding Dolichos lablab lectin (designated DLL) has been purified from seeds of Dolichos lablab (hyacinty bean) to electrophoretic homogeneity by affinity chromatography on an ovalbumin-Sepharose 4B column. The purified lectin gave a single symmetric protein peak with an apparent molecular mass of 67 kDa on gel filtration chromatography, and five bands ranging from 10 kDa to 22 kDA upon SDS-PAGE. N-terminal sequence analysis of these bands revealed subunit heterogeneity due to posttranslational proteolytic truncation at different sites mostly at the carboxyl terminus. The carbohydrate binding properties of the purified lectin were investigated by three different approaches: hemagglutination inhibition assay, quantitative precipitation inhibition assay, and ELISA. On the basis of these studies, it is concluded that the Dolichos lablab lectin has neither and extended carbohydrate combining site, nor a hydrophobic binding site adjacent to it. The carbohydrate combining site of DLL appears to most effectively accommodate a nonreducing terminal α-D-mannosyl unit, and to be complementary to the C-3, C-4, and C-6 equatorial hydroxyl groups of α-D-mannopyranosyl and α-D-glucopyranosyl residues. DLL stringly precipitates murine IgM but not IgG, and the recent finding that this lectin interacts specifically with NIH 3T3 fibroblasts transfected with the Flt3 tyrosine kinase receptor and preserves human cord blood stem cells and progenitors in a quiescent state for prolonged periods in culture, make this lectin a valuable tool in biomedical research.
Three kinds of serine protease inhibitors, members of the Bowman-Birk trypsin inhibitor, were purified from Dolichos lablab seeds and named Dolichos protease inhibitor 1, 2 and 3 (DI-1, DI-2 and DI-3), respectively. Each inhibitor showed a single band with gel mobility at around 15.9, 12.1 and 14.6 kDa on 20% SDS-PAGE under reducing conditions. To characterize inhibitory specificity, the inhibition constant (Ki) for these inhibitors was measured against several known serine proteases. All three Dolichos protease inhibitors (DI-1, DI-2 and DI-3) inhibited the activity of trypsin and plasmin, but had no effect on thrombin and kallikrein (either for human plasma kallikrein or for porcine pancreas kallikrein). DI-1 inhibited chymotrypsin most effectively (Ki = 3.6?10-9 M), while DI-2 displayed inhibitory activity for porcine pancreatic elastase (Ki = 6.2?10-8 M). Pre-treatment of the 33 mg/kg of DI-mixture (active fractions from C18 open column chromatography that included DI-1, DI-2 and DI-3) inhibited the induction of pseudomonal elastase-induced septic hypotension and prevented an increase in bradykinin generation in pseudomonal elastase-treated guinea pig plasma. Also, the increase of kallikrein activity, by injection of pseudomonal elastase, was inhibited by the pretreatment of the DI-mixture in a guinea pig. Since the DI-mixture had no inhibitory effect on kallikrein activity when Z-Phe-Arg-MCA was used as a substrate In vitro, its inhibitory activity in the pseudomonal elastase-induced septic hypotension model might not be due to a direct inhibition of plasma kallikrein in the activation cascade of the Hageman factor and prekallikrein system. These results suggest that the Dolichos DI-mixture might be used as an inhibitor in pathogenic bacterial protease-induced septic shock.
Growth and digestibility experiments conducted on growing East African type goats offered Chloris gayana hay supplemented with one of three high protein (119 - 128 g CP/kg DM) legume hays, Cassia rotundifolia, Lablab purpureus or Macroptilium atropurpureum (Seratro) and crushed maize to investigate the feed intake, digestibility, growth and urinary excretion of purine derivatives. Goats in the supplemented groups had higher total dry matter and nitrogen intakes and higher N retention and body mass gains than unsupplemented counterparts. The digestibility of dry matter, organic matter and neutral detergent fibre increased by protein supplementation. Animals on supplemented diets had higher fractional outflow rates of particulate matter from rumen. The production of protein by ruminal microbes and the efficiency of microbial N production were increased by supplementation. It was concluded that a mixture of low quality grass hay (61.9 CP/kg DM) and either cassia, Lablab or siratro hay and maize grain can provide a productive balanced diet for growing goats.
Polyphenol oxidase (EC.10.3.1) is a widely distributed enzyme in the phylogenetic scale. PPO, a functional copper-containing enzyme in the presence of molecular oxygen catalyses the hydroxylation of monophenols to 0- diphenols and the further oxidation of 0-diphenols to 0-quinons. The generated, unstable, highly reactive 0- quinons, subsequently react with themselves, amino acids or proteins, evolving into brown, black or red heterogeneous polymers responsible for quality loss in many foods. The considerable economic and nutritional loss induced by enzymatic browning is of concern to food processors and researchers. Although numerous studies have been devoted to the biochemical and catalytic properties of PPO and to the inhibition of PPO activity, the physiological functions of PPO in plants remains obscure.
Preliminary investigations in the laboratory revealed the presence of a single PPO in crude extracts of field bean seeds. The purification of PPO from higher plants continues to be a problem compounded by the presence of multiple isoforms. The single form in field bean seeds is ideally suited for structural characterizations and X-ray crystallography studies. As a primary step to understanding the structure, regulation and function of seed PPO is reported here the isolation and characterization of a PPO from field bean seeds.
PPO from field bean seed was purified 34 fold to apparent homogeneity using a four step procedure. The enzyme exists as a single isoform of Mr 120 ± 3.0 k Da and is a tetramer of identical sub-units. Apparent pH optima were 4.0 for catechol and 4-methyl catechol and 5.0 with DOPA as a substrate. Field bean seed PPO is a catecholase, active toward small 0-diphenols, indicating a compact substrate-binding site. The Michaelis constant Km for catechol, 4 - methyl catechol, Pyrogallol and DOPA are 10.5, 4.0, 12.5 and 1.18 mM, respectively. Tropolone was the most effective competitive inhibitor of the enzyme, with a Ki of 0.58µM. Ascorbic acid, potassium metabisulfite and cystein inhibited the enzyme.
An antifungal protein, possessing a molecular weight of 28 kDa and an N-terminal sequence resembling chitinases, has been purified from the seeds of the field bean Dolichos lablab. The procedure involved extraction with aqueous buffer, affinity chromatography on Affi-gel blue gel, and ion exchange chromatography on CM-Sepharose. The protein, designated dolichin, exhibited antifungal activity against the fungi Fusarium oxysporum, Rhizoctonia solani, and Coprinus comatus. Dolichin was capable of inhibiting human immunodeficiency virus (HIV) reverse transcriptase and α- and β-glucosidases which are glycohydrolases implicated in HIV infection. It had very low ribonuclease and cell-free translation-inhibitory activities.
Dolichos lablab, known as field bean, is a legume used as an ingredient in the preparation of some Oriental foods. Its seed has a pale yellow outer coat and a size larger than soybean. It is considered as an alternate of protein source. One area of concern is its quality of volatile components. Most often, legumes may contain undesirable flavor components that contribute to beany flavour. Nevertheless, the volatile composition of this legume has not been recorded in the literature. Thus it was taken to evaluate flavour quality.
Seeds were ground into small particles before extraction. Volatile components were collected by a simultaneous steam distillation and extraction (SDE) apparatus. Extracts were concentrated and analysed by a gas chromatography / mass spectrometry. One hundred and eight compounds were identified which were divided into 14 classes including acid (1), aldehydes (13), alkalines (5), aromatic compounds (4), esters (3), furnas(2), miscellaneous compounds (8), naphthalenes (1), alcohols (33), ketones (22), pyrazines (5), pyridine (1), sulfur - containing compounds (4) and terpenes (6). Twenty nine of them were previously found in soybean headspace samples. Among the 17 compounds reported in the literature in an off-flavour soybean concentrate, 13 of them were identified in the present sample. Quantitatively, the normalized values of 2- pentafuran, 1-pentanal, 1-hexanol, 1-octen - 3-ol and benzaldehyde were much higher than those reported in literature. The results show that Dolichos lablab has similar quality but different quantity of most of the volatile components responsible for the off-flavour in soybean isolate. The legume may be considered to be unacceptable to consumers who are not familiar with it.
Aspergillus flavus is a fungal pathogen of maize causing an important ear rot disease when plants are exposed to drought and heat stress. Associated with the disease is the production of aflatoxins, which are a series of structurally related mycotoxins known to be carcinogenic. Previous research has suggested that the α-amylase of A. flavus promotes aflatoxin production in the endosperm of infected maize kernels. We report here the isolation and characterization of a 36-kDa α-amylase inhibitor from Lablab purpureus (AILP). AILP inhibited the α-amylases from several fungi but had little effect on those from animal and plant sources. The protein inhibited conidial germination and hyphal growth of A. flavus. The amino acid sequence indicated that AILP is similar to lectin members of a lectin-arcelin-α-amylase inhibitor family described in common bean and shown to be a component of plant resistance to insect pests. AILP also agglutinated papain-treated red blood cells from human and rabbit. These data indicate that AILP represents a novel variant in the lectin-arcelin-α-amylase inhibitor family of proteins having lectin-like and α-amylase inhibitory activity.
The effect of harvest time (90 days after sowing (DAS) and flowering) on the bromatological quality of biomass (leaves, stems and whole plant) of canavalia, pigeon pea and Dolichos was determined. In the whole plant, interaction (P<0.05) was only found for K, which was higher in pigeonpea harvested at 90 DAS, without differing from canavalia at 90 DAS and flowering. The lowest ash (P<0.01), crude protein (CP, P<0.01) and Mg (P<0.05) contents were found in pigeon pea differing from Dolichos and canavalia. P was higher (P<0.05) in Dolichos. Ca and crude fibre (CF) were similar in all crops. Harvest time did not affect ash, CP, P, Ca and CF contents. Ash and Ca were higher (P<0.01) without differing from Dolichos for the first measurement. CP, P, K, Mg and CF were similar in this morphological component of three species. Ash and K were higher (P<0.001) at 90 DAS. CP, CF and the remaining minerals were not affected by harvest time. An interaction for P, K and Mg was found in stems. P was higher (P<0.001) in Dolichos at 90 DAS without differing from Dolichos at flowering. Mg was higher (P<0.01) in pigeon pea at flowering without differing from canavalia and Dolichos during harvest time or from canavalia at 90 DAS. The highest ash (P<0.05) and the lowest Ca (P<0.01) contents were found in pigeon pea, although the latter was similar in canavalia. CP and CF were similar in the stems of all the species. Ash was higher (P<0.05) at 90 DAS, while Ca (P<0.01) was higher at flowering. CP and CF were not affected in this morphological components during harvest time. It is concluded that harvest time did not affect the mineral content of the whole plant and leaves, while the stem showed an irregular performance. In general, pigeonpea shows a quality poorer than canavalia and Dolichos. Longer harvest times in these species are recommended.
Plant lectins are a diverse group of proteins / glyco-proteins that have the ability to agglutinate erythrocytes. Seeds of Dolichos lablab contain two distinct sugar- specific lectins that have been purified and studied. D.Lablab seeds have also been found to contain a tetrameric lectin that agglutinates human 0+ erythrocytes. Another lectin called FRIL has also been reported recently from D.Lablab that preserves haemetopoictic progenitors in suspension culture. The galactose-specific lectin from the seeds of Lablab beans could not be purified by affinity chromatography on conventional Sepharose derivatized galactose or lactose gels and has been purified by gel filtrate.
The galactose lectin was shown to cross - react with the antibody to the mannose-specific seed lectin. When the seeds of the Lablab beans were grown to plants, protein extracts form the stems and leaves of three-week old plants showed strong hae- magglutinating activity with rabbit erythrocytes that was inhibited by galactose, its derivatives and lactose. The objective of this study was to isolate this lectin in pure form from the stems and leaves and to compare its properties with those of the galactose- specific and mannose specific seed lectins. This is a report on the purification, physico- chemical properties, carbohydrate binding specificity and immunological properties of this lectin. Stems and leaves of the three-week-old plants contain proteins that strongly agglutinate rabbit erythrocytes but not human erythrocytes, and the agglutinating activity is inhibited by galactose, its derivatives, lactose and N- acetylglactosamine. However, the lectin does not bind to the conventional Sepharose- derivatized galactose or lactose gel and can be purified to homogeneity by ion exchange chromatography and gel filtration. The lectin eluted as a single symmetrical peak from a Biogel P-200 column with a molecular mass of 66 kDa. Purified stem and leaf lectin is a glycoprotein with 3% reducing sugar and is dissociated into two sub-units in SDS-PAGE with molecular masses of 48 kDa and 20 kDa, respectively. The lectin cross-reacts with an antibody to the glucose / mannose - specific seed lectins, suggesting similar antigenic sites in these two lectins. Antibodies raised against the purified galactose-specific seed lectin show specific reactivity with the seed lectin as well as with the stem and leaf lectin, suggesting that they are related proteins.
An experiment was conducted in Bangladesh in 1992 and 1993 to assess the nutritive value and yield of 4 Lablab bean genotypes (IPSA SEAM-1, IPSA SEAM-2, 1986-28-511-27-3 and 1986-6-4-114-29-5) during summer. The pods of four Lablab bean genotypes IPSA SEAM-1, IPSA SEAM-2, IPSA SEAM. 3 and IPSA SEAM-4 were harvested at 10, 15 and 20 days after anthesis. Dry matter, total sugar and carotene contents increased and protein content decreased with pod maturity. However, reducing sugar and ascorbic acid were maximum at 15 days after anthesis. IPSA SEAM-1 and 3 were statistically identical in protein content and was the lowest in IPSA SEAM-2. IPIA SEAM-4 contained highest amount of ascorbic acid (8.09 mg / 100g) and carotene (595. 55mg /100g). Total and reducing sugars were maximum in IPSA SEAM-3 and 1, respectively.
The mean seed protein content of Lablab bean is 26.51 % with a highly significant negative correlation (r = - 0.28) between seed protein and methionine content. D.Lablab (Lablab purpureus) var. lignosus has more protein (20.9-29. 2 %) than variety typicus. This is an underexploited tropical legume that is valued for its nutritional and sensory attributes. According to Venkatachalam et al. (2002), on a dry weight basis, it contains 30% protein. albumin, globulin, prolamin and glutelin, respectively, accounted for approximately 20, 48, 1 and 31 % of the total seed proteins.
It is primarily grown for green pods, which are cooked as vegetable like other beans. The dry seeds are also used in various vegetable preparations. The foliage of the crop provides hay, silage and greenmanure. Medicinal uses are also recorded (Smith, 1976).
|Moisture||86.1 gm||Sodium||55.4 mg|
|Carbohydrates||6.7 gm||Iron||1.7 mg|
|Protein||3.8 gm||Potassium||74.0 mg|
|Fat||0.7 gm||Sulphur||40.0 mg|
|Fibre||1.8 gm||Vitamin A||3121. U|
|Minerals||0.9 gm||Riboflavin||0.06 mg|
|Magnesium||34.0 mg||Thiamine||0.1 mg|
|Calcium||210.0 mg||Nicotinic acid||0.7 mg|
|Phosphorus||68.0 mg||Vitamin C||9.0 mg|
In vitro and in situ evaluation of seed samples were carried out at Debre Zeit Research Station (Ethiopia) of the International Livestock Research Institute. The feed samples consisted of tef straw, wheat bran, dried Lablab purpureus and dried foliage of the multipurpose trees (MPT), namely Sesbania sesban 1198, S. sesban 15019, Acacia angustissima 15132, Leucaena pallida 14203 and mixtures of S. sesban 1198 + L pallida 14203, S. seban 15019 + L. pallida 14203, S. sesban 1198 + A. angustissima 15132, S. sesban 15019 + L. pallida 14203 at a ratio of 2:1. The objectives of the study were to assess the nutritive value of the feed samples and also to consider their potential as supplements to tef straw. The MPTs contained higher crude protein (CP) (216 - 278 g/kg dry matter (DM), and lower neutral detergent fibre (NDF) (204 - 338 g/kg DM) than wheat bran and L. purpureus. Anti-nutritive factors such as soluble phenolics and fibre - bound condensed tannins were high in A. angustissima 15132 and L. pallida 14203, respectively. Wheat bran produced significantly more gas (P<0.001) than either sole or mixtures of MPTs, but the rate of gas production was significantly greater (P<0.001) for MPTs than for wheat bran. Significantly lower (P<0.05) extent and rate of gas production were observed in sole A. angustissima 15132 than in its mixtures with both accessions of S. sesban. L. pallida 14203 yielded significantly lower (P<0.05) In vitro ammonia than its mixtures with both accessions of S. sesban. Sole L. pallida 14203 and A. angustissima 15132 had significantly lower (P<0.05) In vitro dry matter digestibility (IVDMD), in situ potential and effective degradability of DM and nitrogen (N) than their respective mixtures with both accessions of S. sesban. Acid detergent fibre ADF and NDF had a strong negative impact on the rapidly degradable and potential degradability of DM (P<0.001), whereas neutral detergent fibre-bound N (NDE-N) significantly limited (P<0.05) the rate and effective degradability of DM, as well as the extent and the rate of In vitro gas production. IVDMD was also negatively influenced by contents of NDF (P<0.01), ADF and acid detergent lignin (ADL) (P<0.05). in situ extent of DM degradability, potential and effective degradability of DM were positively correlated (P<0.01) with IVDMD and the rate of In vitro gas production was also positively correlated (P<0.05) with the rate of in situ D.M. degradability, potential and effective degradability of DM were positively correlated (P<0.01) with IVDMD and rate of In vitro gas production was also positively correlated (P<0.05) with the rate of in situ DM degradability. It is concluded that all the MPTs and their mixtures have desirable characteristics as potential feed supplements to tef straw compared with wheat bran or L. purpureus. Within the MPTs, A. angustissima 15132 and L. pallida 14203 could be inferior supplements to tef straw compared to S. sesban 1198 or S. sesban 15019. However, mixing both accessions of S. sesban with either A. angustissima 15132 or L. pallida 14203 has the potential for improving the utilization of the latter MPTs. Moreover, it is concluded that In vitro gas production, in situ DM degradation and IVDMD methods could be alternatively used to evaluate the nutritive value of feeds similar to those used in this study.
A feeding experiment was conducted to determine the performance, nutrient digestibility and egg quality of layers fed with 0.50, 100 or 150 g / kg leaf meal of Lablab. Chemical analysis of Lablab gave (g/kg) crude protein 234.0; ether extract 19.0; crude fibre 83.4; ash 116.0 and nitrogen free extract 467.0. Feeding Lablab at 100 and 150 g / kg significantly reduced feed intake and egg production while egg weight, feed conversion efficiency and body weight changes were not affected (P> 0.05) by dietary treatment. Apparent nutrient digestibility of dry matter and crude protein decreased significantly (P < 0.05) with Lablab, while ether extract was not significantly influenced. Internal and external egg quality values were comparable amongst dietary groups except for yolk colour, which was significantly higher (P< 0.05) in layers fed with Lablab compared to those without. Diet on boiling had no significant effect (P> 0.05) on the proportion of egg components, but boiling affected a percentage reduction of 62, 56 and 52 in the egg yolk colour of 50, 100 and 150 g / kg Lablab fed layers, respectively. The persistence of the colour change after withdrawal of Lablab ranged from 5 days (50 g / kg) to 15 days (150 g /kg). Based on egg quality, lack of mortality and similar biological efficiency, it may be possible to include Lablab in layers diets upto 100 and 150 g /kg in situations of acute scarcity and / or high cost of grain and concentrates.
The effect of processed Lablab (PLB) bean meal supplementation in the diet of Cyprimus carpio was studied. Soybean was substituted for raw Lablab (RLB) and PLB meal on equal nitrogen basis in conventional fishmeal. The diets were subjected to proximate analysis and digestibility studies. Results showed that PLB bean diets have comparable crude protein and lipid digestibility coefficients. The carbohydrates digestibility was highest in fish fed with fermented LB bean diet and lowest in those fed on RLB bean diet. Crude fibre digestibility coefficients of fish fed on control and PLB bean diets differ significantly from those fed with RLB bean diet. Gross energy of PLB bean diet ranged from 17.1 to 17.8 KJ/ g. Energy retention of 15.0, 12.6 and 12% was obtained in fishes fed on cooked, control and fermented diets, respectively. The feed conversion co-efficiency was 166.6 in fish fed with the control diet, which differs significantly (P< 0.05) from those fed on PLB bean diets (152-159). Fish fed with the cooked LB bean diet has the highest specific growth rate and feed convession ratio. A direct positive linear and quadratic relationship exists between final and feeding period in C. carpio fed on the test diets.
This study showed that heat processing (cooking and toasting) and fermentation can significantly improve the digestibility of LB beans. Significant improvement in the growth performance of C. carpio can be obtained by feeding the fishes with cooked LB bean diets. The observed growth pattern can be fully described using quadratic equations.
The cooking quality and composition of the seed of 5 Dolichos lablab cultivars: Pusa early Prolific, IC6857, IC 16863, JDL 53 and JDL-79 were studied. On a dry matter basis, the percentage of crude protein varied from 22.1-28.3%. The crude fat, total carbohydrate and crude fibre contents ranged from 1.6-2.2, 57.5-64.7 and 6.0-10.6%, respectively. The amounts of Ca, P, Fe and K varied from 28-48, 330-415, 5.6-6.9 and 10-15 mg/100 g, respectively. The cultivars exhibited trypsin inhibitor activity (TIA, 8350-8800 TIU /g). The contents of tannin and hydrocyanic acid varied from 672 - 803, 925-2025 and 32-42 mg/100g, respectively. Boiling for 30-60 mts and pressure cooking for 10 mts had significant effects on the contents of mature seeds of D.Lablab. Cooking increased the moisture content and reduced TIA and protein, crude fat, crude fibre and carbohydrate contents of seeds. JDL 79 was superior to other cultivars as it recorded the highest water absorption (124%) and solid dispersion (14%) levels. Pressure cooking for 15 mts had the most favourable effect on seed nutritive value.
Hyacinth bean although used in the Orient as an alternate source of protein, its utilization has not been common in other places. One area of concern is its quality of volatile components. Most often, legumes may contain undesirable beany flavour. But the volatile composition of this legume has not been recorded in literature. Hence this study to determine the volatile composition of this legume and to evaluate its flavour quality. Volatile components collected from steam distillation and extraction were concentrated and analyzed by a gas chromatography / mass-spectrometry. One hundred and eight compounds were identified which were divided into 14 classes including acid (1), aldehydes (13), alkalines (5), aromatic compounds (4), esters (3), furnas (2), miscellaneous compounds (8), naphthalenes (1), alcohols (33), ketones (22), pyrazines (5), pyridine (1), sulfur-containing compounds (4) and terpenes (6). Twenty nine of them were previously found in soybean head space samples. Among the 17 compounds reported in the literature in an off-flavour soybean concentrate, 13 of them were identified in the present sample. Quantitatively, the normalized values of 2-pentafuran, 1-pentanol, 1-hexanol, 1-octen-3-ol and benzaldehyde were much higher than those reported in literature. The results show that Dolichos lablab has similar quality but different quantity of most volatile components responsible for the off-flavour in soybean isolate. This legume may be considered to be unacceptable to consumers who are not familiar with it.
Eight whole legumes, viz., Bengal gram (Cicer aurietinum), broad beans (Vicia faba), cowpea (Vigna catjang), field beans (Dolichos lablab), green gram (Phaseolus aureus Roxb), horse gram (Dolichos biflorus), lentils (Lense esculenta) and French beans (Phaseolus vulgaris), were cooked under pressure or in microwave oven and were analysed for nutrient composition. Raw legumes served as control. The range of nutrients analysed in 100g cooked samples were: moisture-62.8-69.7g, protein-14.7-24.3g, fat-0.9-5.9 g, ash-1.7- 4.6 g and iron-3.3-8.6 mg. Cooking methods did not affect the nutrient composition of legumes. However, thiamine decreased in cooked samples. Cooking altered the dietary fibre content of some legumes. The mean In vitro protein digestibility of pressure-cooked and micro-waved samples was 79.8% and 74.7%, respectively. The In vitro starch and protein digestibility of pressure-cooked samples were higher.
Lablab purpureus is cultivated worldwide and used for forage and food in underdeveloped nations. Small acreages are grown in California and Texas. More than 90 accessions are conserved at the USDA, ARS, plant Genetic Resources Conservation Unit, Griffin, GA. Lablab purpureus contains potential bioactive phytochemicals in sufficient quantity to be utilized in the pharmaceutical markets. The lectin FRIL, which was discovered in Phaseolus vulgaris, is present in significant quantities in the seeds of Lablab purpureus. Lectins are known to play in plant defences against pathogen attack and have been reported to interact with specific glycoproteins on human cells and induce various biological responses. FRIL has been observed to interact with the FLT-3 receptor on human stem cells and prevent them from proliferating or undergoing apoptosis. Seven fold variability in the quantity of FRIL among 22 Lablab purpureus accessions was found. Genotypes with high quantities of FRIL have the potential to be utilized in the natural product or phytopharmaceutical industries.
The lectin FRIL was extracted and assayed from 22 older Lablab purpureus accessions originating from 13 countries, stored at -18°C at the USDA, ARS, Plant Genetic Resources Conservation Unit, Griffin, GA, and from freshly grown L. purpureus genotypes produced in the field at the University of California, San Diego, CA. FRIL was isolated using sugar-based affinity beads and then quantified and examined by SDS-PAGE. FRIL from L. purpureus demonstrates a 5-band pattern on SDS-PAGE. This heterogeneity results from the use of 2 alternate N- termini and 2 alternative glycosylation sites on the alpha chain. More than 7-fold variability in the quantity of FRIL among L. purpureus accessions was found. Fresh and older L. purpureus seeds were consistent in terms of high FRIL producers and low FRIL producers. It was also observed that a large amount of heterogeneity in the relative size and colouration of the seeds suggesting that sufficient time and distance separates the beans to allow a certain amount of genetic drift. Genotypes with high FRIL indicate their potential to be utilized by the natural product of phytopharamaceutical industries as a new medicine.
Arsibulls and heifers were fed for 111 days with haricot bean residue alone or supplemented with 0.5, 1.0 or 1.5% of their body weight with Lablab hay. Supplementation, especially with 1.0 and 1.5%, increased the dry matter intake and weight gain (P<0.001). The supplements were economically profitable; unsupplemented, there was a loss of 0.275 Ethiopian Birr (ETB)/ day, but with 0.5, 1.0 and 1.5% Lablab supplementation, there was a profit of 0.051, 0.320, 0.425 ETB/day, respectively.
A laboratory study was conducted with field grown pearl millet (Pennisetum americanum) and Lablab (Lablab purpureus) to examine the effects of addition of Lablab in varying amounts on the quality of millet silage. Combinations compared were 0:100, 15:85, 30:70 and 50:50 mixtures of Lablab and millet, respectively. All silage treatments contained similar concentrations of dry matter, organic matter and ether extract. In - corporation of Lablab led to a small increase in crude protein, crude fibre and nitrogen - free extract. All silages showed low crude protein concentrations and would barely supply N requirements for maintenance of cattle. The lactic acid content of the silage increased as the proportion of Lablab in the mixture increased. The silage pH values, which ranged from 4.1-4.5, showed that all Lablab-millet mixtures were adequately fermented with favourable aroma and colour. The Ca and P concentrations increased with higher incorporation of Lablab, while the converse was the case with Mg, Na, K and S. Mineral supplements, in particular S and Na, would need to be fed if these silages constituted a high proportion of the diet of cattle, especially lactating cows. Field studies are required to determine if these results can be duplicated on a practical scale, while feeding studies with ruminants will determine the acceptability of the silages and animal performance.
Effects of selected Hofmeister anions, namely, Na2SO4, NaCl, NaBr, NaCl, NaClO4 and NaSCN, on the functional properties of a protein isolate prepared from Lablab seeds (L. purpureus) were investigated. The results of water absorption capacity indicated that highest water absorption was recorded in solution of Na2SO4 and the lowest in NaSCN solutions. Reduction in water absorption capacity followed the Hofmeister series in the order Na2SO4 > NaCl > NaBr > Nacl > NaClO4 > NaSCN. Protein solutions prepared in chaotropic (Nacl, NaClO4, NaSCN) salts had better foam capacity, foam stability, emulsifying activity and emulsion stability than solutions prepared with kosmotropic salts (Na2SO4, NaCl, NaBr). The results also indicate that increase in foam capacity and stability followed and Hofmeister series in the order Na2SO4 < NaCl < NaBr < NaCl < NaClO4 < NaSCN. When least gelation concentration (LGC) was used as the index of gelation capacity at various salt concentrations, the lowest LGC were observed in NaSCN and the highest LGC in protein solutions prepared with Na2SO4.
The present study reported the purification, characterization of alkaline protease and its possible involvement in moblization of storage proteins. The mobilization of seed storage proteins represents one of the most important post-germinative events in the growth and development of seedling. The proteolytic enzymes play a central role in the biochemical mechanism of germination. The alkaline protease from the cotyledons of 4-day old germinating Indian bean seedlings was purified to 198 folds by a four step procedure comprising-crude extract, (NH4)2SO4 fractionation, DEAE-cellulose and finally casein-alginate affinity chromatography. The alkaline protease was shown to be homogeneity, as attested by a single protein band on both native PAGE and SDS-PAGE. It is a monomeric enzyme with molecular mass of 40 kDa and exhibited sharp pH optima at 8.8 with casein. It has been characterized by seeing the effect of various inhibitors and metal cofactors on the alkaline protease activity. The enzyme activity was markedly increased with Zn and significantly inhibited by the metal chelating agents-EDTA and 1, 10-phenanthroline. These results suggest that the alkaline protease is a metalloenzyme.
The positive correlation between development of acid neutral and alkaline protease (proteinases) (azocaseinolytic) with protein depletion suggest the involvement of these protease in the degradation of proteins in germinating Indian bean (Dolichos lablab). These proteases increased in the early stages of germination and decreased thereafter. However, the activity of the acid proteases was higher throughout the germination period compared with the activities of neutral and alkaline proteases. The acid protease from the cotyledons of 4 - day old germinating Indian bean seedlings was purified to 152 - bold by 5 - step procedure, which consisted of crude extract from cotyledons (NH4)2SO4 fractionation, DEAE - cellulose, CM - cellulose and casein - agarose affinity chromatography. The molecular mass of acidic protease was 32 kDa.
Lablab is an ancient legume species widely distributed in Indian sub-continent, Africa and South East Asia, and is consumed locally as a grain legume and vegetable for more than 3000 years (Fuller, 1999). Uses of Lablab bean varies with the region where it is grown; may be as a vegetable or pulse for human consumption or as a forage crop. Young pods and immature green pods are cooked as vegetable like other beans. Dry seeds are used for various vegetable preparations. Medicinal uses are also reported (Smith, 1976). The forage crop provides hay, silage and greenmanure. Lablab plants may be grazed by cattle, sheep and goats. After the harvest of dry pods, the dried plant material may be used as annual feed. In Australia Lablab bean varieties like HighWorth and Rongai White have been used successfully as cover crops to suppress weed growth and prevent soil erosion, and as a green manure in mixed crop-livestock-systems. Over the past 50 years, it has become an important annual forage crop (Pengelly and Maass, 2003). Lablab bean can be intercropped with finger millet, maize, sorghum and groundnut and it provides both vegetable and animal feed.
Field bean (Dolichos lablab) contains a single isoform of PPO (polyphenol oxidase) - a type III copper protein that catalyses the o-hydroxylation of monophenols and oxidation of o-diphenols using molecular oxygen - and is a homotetramer with a molecular mass of 120 kDa. The enzyme is activated manyfold either in the presence of the anionic detergent SDS below its critical micellar concentration or on exposure to acid-pH. The enhancement of kcat upon activation is accompanied by a marked shift in the pH optimum for the oxidation of t-butyl catechol from 4.5 to 6.0, an increased sensitivity to tropolone, altered susceptibility to proteolytic degradation and decreased thermostability. The Stokes radius of the native enzyme is found to increase from 49.1±2 to 75.9±0.6 Å (1 Å=0.1 nm). The activation by SDS and acid-pH results in a localized conformational change that is anchored around the catalytic site of PPO that alters the microenvironment of an essential glutamic residue. Chemical modification of field bean and sweet potato PPO with 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide followed by kinetic analysis leads to the conclusion that both the enzymes possess a core carboxylate essential to activity. This enhanced catalytic efficiency of PPO, considered as an inducible defence oxidative enzyme, is vital to the physiological defence strategy adapted by plants to insect herbivory and pathogen attack.
A galactose-specific lectin has earlier been isolated from the seeds of Dolichos lablab in our laboratory by conventional protein purification methods. We now established conditions to bind the lectin on Sepharose-galactose gel in the presence of 1.5 M ammonium sulfate in Tris-buffered saline, pH 7.4. It can be specifically eluted with 0.3 M galactose. The purified lectin is a glycoprotein, binds to Con A, agglutinates erythrocytes, and has an apparent native molecular weight of 120 ′ 5 kDa. In SDS-PAGE under reducing conditions, it dissociates into two subunits of molecular mass (Mr) 31 and 29 kDa. Among a number of sugars tested for inhibitory activity of the lectin, galactose was found to be a potent inhibitor. Rabbit polyclonal antibody to the purified lectin specifically reacted with the lectin subunits in Western blot analysis and additionally, an antibody raised to the isolated 31 kDa subunit show reactivity with both the subunits. Amino terminal sequences of both the subunits are identical. The purified lectin is stable up to 40 °C with a pH optimum of 7.4. The lectin has a high content of acidic amino acids and lacks sulfur-containing amino acids. Chemical modification of the lectin with group-specific reagents indicates the possible role of histidine, lysine, and tyrosine residues in lectin activity.
The pattern of mobilization of seed storage protein and the development of proteolytic enzymes have been investigated in Indian bean (Dolichos lablab var. lignosus) seeds during a 10-day germination period. Accumulation of free amino acids synchronized with rapid proteolysis and higher levels were maintained throughout the germination period. The presence of proteases (acid, neutral and alkaline) with three different pH optima increased in the early stages of germination and declined later. While the carboxypeptidase with a pH optimum of 5.5 increased rapidly up to day 4 and declined thereafter, the lencine aminopeptidase with pH optimum of 6.8 reached maximum level by day 2 and declined thereafter. The higher activities of aminotransferases were also observed in the earlier stages of germination. The developmental pattern of proteases during germination period in the degradation of storage proteins in Indian bean appears to suggest that lencine aminopeptidase be involved in the initial stages of germination followed by endopeptidases and carboxypeptidases in the tater stages.
The raw dry Indian bean having a very high trypsin inhibitory activity which progressively decrease by 51% during the 12 h soaking period and further reached to 17% at 32 h germination period. However, the overall fall in polyphenols was 70%, tannins 46%, phytic acids 36%, phytate phosphorus 30 and 40-50% stachyose and raffinose were noticed. The present study also evaluated the changes of anti-nutritional factors of germinating Indian bean by subjecting to boiling, roasting and pressure cooking. Maximum reduction was observed in TIA and phytic acids with roasting, while the boiling and pressure cooking decreases the levels of polyphenols and tannins. Germination was more effective method in reducing trypsin inhibitor activity, tannins, polyphenols and phytic acid than the various cooking treatments.
Hyacinth bean (Lablab purpureus (L.) sweet) seeds from Indonesia were characterized for the purposes of usage as a protein source. Protein isolate was prepared from the seeds using an isoelectric method, which was also used to characterize the physicochemical and functional properties. Hyacinth bean seeds have a moderate concentration of protein (17.1 ± 1.5%), and low concentration of HCN (1.1 ± 0.1 mg/100 g). However, before using the seeds as food, some treatments are needed to reduce their anti-nutritional factors, since the contents of trypsin inhibitor and phytate are 0.15 ± 0.02 TIU/mg and 18.9 ± 0.2 mg/g, respectively. Using the isoelectric preparation, the yield of protein isolate was low (7.38 ± 0.2 g per 100 g of the seeds), but the protein isolate had good colour, neutral odour, high protein content (89.8 ± 0.82%), and low ash (2.97 ± 0.36%). The protein isolate also had good functional properties, such as solubility, foaming capacity, and emulsifying activity. However, the foaming and emulsifying stabilities were low.
Lablab (L. purpureus) is one of the underutilized crops in Africa that have multiple-purpose uses. Despite its wide ecological adaptability and ability to cope with different environmental adversities, it is neglected in research and development as human food. Such lack of interest threatens existing land races by genetic erosion. Participatory evaluation of 29 Lablab accessions included 25 core-collection members and 4 local land- races. Panelists included a broad range of farmers and extension workers from East African countries. Leaf and pod-meal organoleptic taste assessments as well as visual evaluation of pod morphology were conducted at The World Vegetable Centres Regional Centre for Africa (AVRDC-RCA) near Arusha, Tanzania. Logistics regression parameters were used to compare the acceptability of accessions. In addition, principal component analysis (PCA) was applied to reveal patterns of variation among them. It was found that the acceptance of Lablab accessions varied considerably for meals made from leaf (very low selection intensity) or pod (very high selection intensity) as well as for pod morphology.
Participants highly appreciated meals prepared from leaves of accessions ILRI 11632, CPI-30212, CPI. 76996 and CPI 29398, whereas pod morphology of accessions CPI 106002 (cv. Valore) and CPI 81626 was particularly liked due to their long and slender pods. The acceptance of the pod-meal of accession CPI 100602 was also outstading.
Multifunctional proteins or chimeras are structurally single proteins, but exhibit multiple catalytic or binding functions. A 120kDa protein purified to homogeneity as a polyphenol oxidase (PPO) from field bean (Dolichos lablab) with a specific activity of 2954U/mg, is perse a galactose specific lectin. The purified protein is a glycoprotein composed of two subunits (Mr.=31000&29800). The partial amino acid sequence determined by sequential Edman analysis of peptides derived by enzymatic cleavage indicated a high homology to the legume galactose specific lectins. The partial cDNA sequence is homologous to DB58 of Dolichos biflorus. A galactose specific lectin of Indian lablab bean strikingly has the same amino terminal sequence reported for field bean PPO. The agglutinating activity of PPO was 1282 U/mg. These results taken together indicate a chimera of PPO and agalactose specific lectin. The catalytic activity and sugar binding activities are independent of each other. Tropolone a competitive inhibitor of PPO did not inhibit agglutination. Galactose and N-acetylgalactosamine had no effect on PPO activity. The purified protein also exhibits a-galactosidase activity. Field bean PO antibodies cross-react with several legume lectins. Phylogenetic analysis of legumes lectins show a single cluster for the galactose specific lectins suggesting functional and structural conservation. PPO and lectins have both been implicated to play a vital role in the defense mechanism of plants. The occurrence and complementarity's of two independent defense mechanisms exhibited by a single protein needs further investigation.
The changes in nutrient composition, trypsin inhibitors, phytic acid, tannins and in-vitro digestibility of protein of Lablab bean during 5 days of germination were studied. The crude protein content was significantly increased, whereas lipid and carbohydrate contents decreased. Antinutritional study revealed that trypsin inhibitor activity and phytic acid content decreased as germination period increased. In contrast, there was a progressive increase in tannins content with increase in germination time.
The effect of different traditional processing methods, soaking, cooking roasting, autoclaving and germination on the nutrient composition antinutritional factor, and in-vitro digestibility in Dolichos lablab seeds were investigated. Germination significantly increased the protein and moisture content, whereas roasting and autoclaving decreased their contents. Crude lipid content, was significantly reduced by various processing. Ash content varied significantly between raw and processed samples. The trypsin inhibitor activity and phytic acid content significantly decreased by different process methods, while the amounts of tannins significantly decreased. The cooking of presoaked seed appeared to be the most effective method for reducing trypsin inhibitor activity. The reduction in content of phytic acid was found to be somewhat greater in roasted sample compared to others. Germination significantly increased tannins content compared to the other traditional methods. Germination was the most effective in improving protein digestibility when compared to soaking and cooking.
Albumin and globulin fractions of Indian bean seeds exhibit different mobilization patterns during the 8-day germination period. The albumin degradation was lesser in the early stage and reached a maximum in the later stages of germination. However, the globulins were degraded steadily from the start of imbibition. The influence of the embryonic axis on albumin and globulin degradation was also evaluated by using axis-attached and axis-detached cotyledons. The overall loss of globulins and albumins in axis-detached cotyledons was only 49%and 60%of the basal level, while in axis-attached cotyledons it was 81 % and 94 %. These results were confirmed by polyacrylamide gel electrophoresis (PAGE), and reveal the faster degradation of high molecular weight (HMW) polypeptides of globulins in the early stages of germination with increased utilization of albumins in the later stages. The results obtained showed the role of the embryonic axis in seed storage protein mobilization.
Val bean (Lablab purpureus L.) proteins were fractionated using the Osborne protein fractionation scheme and biochemically characterized. The seed flour contained 302 g kg−1 protein (micro-Kjeldahl N × 6.25) on a dry weight basis. Albumin, globulin, prolamin, and glutelin accounted for 22.8%, 45.1%, 1.8% and 30.3%, respectively, of the total soluble seed proteins. Among the solvents tested, 0.1 mol L−1 aqueous NaOH was the most effective protein solubilizer. Isoelectric focusing indicated the seed proteins to be predominantly acidic (pI range was 4-7). Val globulin is a glycoprotein composed of at least three polypeptides in the molecular mass range 51-64 kDa. Albumin fraction had the highest trypsin inhibitory activity, while the globulin fraction registered the highest hemagglutinating activity. Sulfur amino acids were the first limiting amino acids in the total seed proteins. The proportion of essential to total [E/T(%)] amino acids for the bean flour was 36.97%. Among the protein fractions, glutelin fraction had the highest E/T (42.86%) followed by albumin (41.57%), globulin (39.87%), and prolamin (39.15%). Native globulin, although resistant to pepsin, was effectively digested In vitro upon moist heat (100 °C, 30 min) denaturation.
The healthy Indian bean (Dolichos lablab L.) seeds were soaked for 12 h and allowed to germinate (sprout) at room temperature 27±2 C for a period of 32 h. Seedlings were withdrawn at designated time intervals and used for analysis of anti-nutritional factors like trypsin inhibitory activity (TIA), phytic acid, polyphenols and tannins of dried and germinated cotyledons. They were also evaluated regarding their changes by subjecting to different cooking treatments - boiling, roasting and pressure cooking. Findings - The raw dry Indian bean had a very high TIAwhich decreases progressively to 17 per cent at 32 h germination period. An overall fall in polyphenols of 70 per cent, tannins 46 per cent, phytic acids 36 per cent and phytate phosphorus to 30 per cent was noticed during the 32 h germination period. Maximum reduction was observed in TIA and phytic acids with roasting, while the boiling and pressure cooking decreases the levels of polyphenols and tannins. Originality/value - The paper proves that germination is a more effective method in reducing TIA, tannins, polyphenols and phytic acid than the various cooking treatments.
A new unique lectin (galactose-specific) purified from the seeds of Dolichos lablab, designated as DLL-II is a heterodimer composed of closely related subunits α and β. These were separated by SDS-PAGE and isolated by electoelution. By ESI-MS analysis their molecular masses were found to be 30.746 kDa (α) and 28.815 kDa (β) respectively. Both subunits were glycosylated and displayed similar amino acid composition. Using advanced mass spectrometry in combination with de novo sequencing and databse searches for the peptides derived by enzymatic and chemical cleavage of these subunits, the primary sequence was deduced. This reveled DLL-II to be made of two polypeptide chains of 281(α) and 263(β) amino acids respectively. The β subunit differed from α subunit by the absence of some amino acids at the carboxy terminal end. This structural difference suggests that possibly, the β subunit is derived from the α subunit by posttranslational proteolytic modification at the COOH-terminus. Comparison of the DLL-II sequence to other leguminous seed lectins indicates a high degree of structural conservation.
A partially purified protein fraction was isolated from seed flour of the Indian wild bean, Lablab purpureus, by ion exchange and size-exclusion chromatographies. Partially purified L. purpureus proteins had hemagglutination and glycoslyation properties similar to those of lectins or lectin-like proteins from other pulses. Data obtained from two-dimensional gel electrophoresis, MALDI-TOF, and MALDI-TOF/TOF and N-terminal protein sequencing of the isolated polypeptides from L. purpureus demonstrated that the extract contained proteins similar to isoforms of arcelins 3 and 4 and pathogenesis-related protein 1 (PvPR1) of Phaseolus vulgaris. L. purpureus proteins were resistant to degradation by the commercial enzymes trypsin and chymotrypsin and were moderately resistant to pepsin, but were readily hydrolyzed to smaller peptides by papain. Insect feeding bioassays of the extract with the storage pests Rhyzopertha dominica and Oryzaephilus surinamensis, internal and external feeders of grain, respectively, demonstrated that L. purpureus proteins at 2% in the diet resulted in retarded development. However, a 5% dose of the L. purpureus fraction resulted in complete mortality of all larvae in both species. This study has demonstrated that proteins in the partially purified L. purpureus extract have the potential to control storage pests in cereals transformed with L. purpureus defense-related genes, but the need for more studies regarding efficacy and safety is discussed.
The polyphenol oxidase (PPO) of field bean (Dolichos lablab) is a tetramer made up of two subunits of mass 29,000 and 31,000 Da. The amino acid sequence of the tryptic peptides showed approximately 90% sequence identity to the D-galactose specific legume lectins. The haemagglutinating activity of a pure and homogenous preparation of PPO measured using human erythrocytes was 1261 HAU mg−1 protein and was inhibited by D-galactose. Purification by galactose-sepharose chromatography also indicated that the PPO and haemagglutinating activities were associated with a single protein. Crude extracts of other legumes did not exhibit PPO activity, yet cross reacted with anti-PPO antibodies. This dual function protein with PPO and haemagglutinating activity is unique to field bean. The two activities are independent of each other occurring at different loci on the protein. These observations further evidence and strengthen the assumption that galactose specific legume lectins have enzymatic function. Both PPO and lectins are proteins that play a vital role in the defense mechanism of plants. The complementarity of these two simultaneous and independent powerful defense mechanisms exhibited by a single protein renders it a candidate gene for the development of inbuilt plant protection.
Field bean (Phaseolus vulgaris L.) is an important food grain legume in Africa. Its importance in Eastern and Southern Africa has grown in recent years. Information about the preference of sweet bean type and seed sources used by farmers was obtained from a collection campaign conducted in Manicaland, Zimbabwe. Eighty-two bean seed samples were collected and after removal of impurities and off-types, were visually separated into two categories: bad (shrivelled, small and discolored) and good. Fungi were identified on 82 sweet bean types using the Blotter technique. Sweet bean type of any seed size of between 18.4 and 52.8 g/100 seeds (mean: 31.1 g) was the most preferred, being cultivated by 84.1% of the farmers surveyed. Home-saved seed was identified as the main seed source, the source for 73.2% of farmers visited. Some farmers were able to produce good quality seed. About 19% of seed samples had less than 1% impurities; and in 3.7% of the samples sweet bean seed was not mixed with other varieties; 61% of tested samples had less than 10% bad seed. About 3.7% of the seed samples had no seed-borne fungal infection, and for those with infection some samples had infection levels less than individual fungi tolerance levels. The pathogen Phaeoisariopsis griseola was not identified in the seed collected. The most common fungi in the area were: Fusarium oxysporum (identified in 73.2% of seed samples tested), Alternaria alternata (70.7%), and Colletotrichum lindemuthianum (51.2%). A group of relatively minor (less frequent) fungi comprised of Fusarium solani, Cercospora canescens, Phoma exigua, Macrophomina phaseolina and Rhizoctonia solani, and were identified in 23.2, 18.3, 13.4, 34.1 and 6.1% of tested seed samples, respectively. The identified fungi were found alone or more commonly associated together with up to six fungal types per farm (96.3% of the cases with a mean of 3.0 per seed sample). Mean seed infection levels varied from 0.8% for C. canescens and M. phaseolina and 2.2% for F. oxysporum and A. alternata. Some high values per farmer of 13.5, 14.5 and 20.5% were obtained with A. alternata, C. lindemuthianum and F. oxysporum, respectively. Although the preferred sweet bean type was susceptible to several seed-borne fungi some of the farmers produced good quality seed and the production of improved seed by even more farmers could be promoted.
Mucuna pruriens (MP) has been used in the Indian system of traditional medicine (Ayurveda). MP has been proposed as a cognitive enhancer and nutritional supplement due to the high nutritional value and low cost. The object of this study was to access nutritional supplement (NS) and cognitive enhancement (CE) qualities of MP in a group of school children aged 6-9 years from marginal urban area of the City of Guayaquil, Ecuador. The universe consisted of 51, school children 6-9 years old, out of a total school population of 120 students. A pediatric assessment was performed at the school through medical history, anthropometric measurements, and auscultation of vital organs. Blood count, glucose, total protein physico-chemical urine tests were performed. Nutritional supplement studies were sustained for 6 weeks. After 6 weeks, analyzes were repeated by pediatric MD. The Bender-Koppitz Test was selected to measure the maturity level of visual-motor perception in the students. Prior to intervention, children manifested impulsive aggressive behaviour and lacked the capacity to plan. After the intervention both attention and cognitive adjustment tended to improve in the population. MP supplementation proves as a potential candidate for both nutritional and cognitive supplementation.
This underutilized variety of Dolichos lablabbean seed serves as a good source of natural antioxidants, which may be effective in reducing the risk of occurrence of certain diseases. This study was undertaken for the first time to address the limited knowledge regarding the, antioxidant activities, DNA damage inhibitory activity, bovine serum albumin (BSA) damage inhibitory activity, antiacetylcholinesterase, and anti-porcine ɑ- amylase in the lablab bean seed. The antioxidant capacity of lablab bean seeds were evaluated for their potential antioxidant activities using the ferric-reducing/antioxidant power assay (FRAP), free radical-scavenging activity (DPPH), nitric oxide (NO) radical-scavenging assay, and 2,20-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The lablab bean extract exhibited good antioxidant activity by effectively scavenging FRAP, DPPH, NO, and ABTS radicals. Additionally, excellent protective effects against BSA damage, as well as natural ɑ- amylase inhibitors were also shown. The bean extract had protective effects against DNA damage.