Distribution of seed protein fractions and amino acids in different anatomical parts of chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan L.)

Studies on protein fractionation in seed coat, embryo, cotyledons and whole seed were made to observe the differences, if any, between chickpea and pigeonpea. Results indicated that globulin was the major fraction of embryo and cotyledons of these legumes. Seed-coat nitrogen was observed to be mostly comprised of nonprotein nitrogen and glutelin fractions and thus differed from other components in both chickpea and pigeonpea. The albumin fraction of cotyledons of both crops had the highest concentration of sulphur amino acids, methionine and cystine. Glutelin contained a considerably higher concentration of methionine and cystine than did globulin in chickpea and pigeonpea. This suggests that lines with higher glutelin should be identified to improve their protein quality. The amino acid compositions of different seed components did not show large differences between these two pulse crops.Submitted as JA no. 180 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).     

Characterization of seed storage proteins of urdbean (Vigna mungo)

Dehulled and defatted flour of urdbean (Vigna mungo), Var T-9, contained 25% protein with maximum contribution by globulins (63%). Albumins and glutelins contributed 12% and 21% respectively, whereas prolamins were present only in traces (1%). Globulins were further fractionated into legumin and vicilin type proteins which were present in the ratio of 4:1. All the protein fractions were heterogenous in nature as revealed by high performance liquid chromatography. SDS-polyacrylamide gel electrophoresis revealed the total protein sample to contain 21 different components with molecular weights ranging from 8.92 to 117.49kd. Albumins, globulins, prolamins and glutelins resolved into 4, 8, 6 and 13 different sized components of molecular weights ranging from 10.23 to 25.53, 10.84 to 112.72, 10.33 to 51.52 and 8.91 to 112.72kd, respectively. Amino acid analysis of all fractions revealed that glutamic acid was present in maximum concentration followed by aspartic acid and lysine. Just like other pulse proteins, the urdbean proteins were also deficient in sulphur containing amino acids.     

Amino acid compositions of different protein fractions in developing grains of NP 113 barley and its high lysine Notch-2 mutant

The percent distributions of protein fractions namely albumin + globulin, prolamine and glutelin were studied in developing grains of NP 113 barley and its high lysine mutant Notch-2. During development the percentage of albumin + globulin fraction decreased in NP 113, while those of prolamine and glutelin remained unchanged. The increase in prolamine was substantial from 24 to 31DAA. In Notch-2 the trend followed by albumin + globulin and prolamine was like that in NP 113, while the glutelin fraction showed an increase as compared to 10 DAA. The percent of albumin + globulin was slightly higher in Notch-2 as compared to NP 113. The absolute amount (mg/grain) of all the protein fractions increased during development in both NP 113 and its mutant Notch-2. During the grain development the prolamine content was substantially lower in the mutant than in the parent NP 113. The albumin + globulin content per endosperm was in general also higher in NP 113 than Notch-2. Amino acid analysis of the protein fractions did not reveal significant changes in lysine between NP 113 and Notch-2. Thus, the improvement in lysine in the mutant is primarily due to reduced synthesis of the prolamine fraction and not due to an increase in lysine in the mutant hordein fraction. Part of the improvemenht in lysine may also be due to increase in the percentage of albumin + globulin fractions which is lysine rich.Part of the Ph.D thesis submitted by S. Joshi to P.G. School, IARI, New Delhi.     

Studies on green gram (Phaseolus aureus) protein concentrate and flour

Protein isolate from green gram (Phaseolus aureus) was prepared and the chemical composition was determined. It contained 64.04% protein, 1.8% total lipids, 27.64% total carbohydrates, 1.68% crude fibre and 4.84% ash. Iron, calcium, magnesium, copper, zinc, potassium and sodium were determined. The limiting amino acid in the protein isolate was lysine. In vitro digestibility pepsin followed the pancretion was the highest and the lowest was the digestion by pepsin alone. Water absorption, oil absorption, emulsion capacity and nitrogen solubility index (NSI) of the protein isolate were 2.26g/g, 1.24g/g, 31.4g/g and 6.8g/g, respectively. For comparison the same functional properties were determined for the flour of green gram. Replacing 5 and 10% of the wheat flour with green gram flour improved the mixing properties of dough and produced good acceptable bread. However, the addition of 15% green gram flour weakened the dough and lowered the quality of bread. Replacing 2.5, 5 and 7.5% of wheat flour with protein concentrate also weakened the mixing properties of the wheat dough and decreased the bread quality.     

Studies on protein quality of green gram (Phaseolus aureus)

Raw green gram contains trypsin inhibitor (5.6 × 10^–3 units/0.1 g) while cooking destroyed the trypsin inhibitor in green gram. No destruction was observed in the case of lysine, methionine, cystine, threonine and tryptophan. Sulphur containing amino acids have been found to be the only limiting amino acids in green gram from studies on blood levels of amino acids and PER experiments. Raw green gram, when fed as a sole source of protein promoted an extremely low growth rate, (13.2 g/4 weeks) and PER (0.77) in rats. Cooking slightly improved the nutritive value of the gram, as indicated by increase in gain in body weight (24 g/4 weeks) as well as PER (1.22). The presence of inhibitors in green gram did not appear to affect some of the essential amino acids as observed from the blood amino acid levels.     

Protein and amino acid composition ofFagopyrum (buckwheat)

Seven varieties of buckwheat, two Indian selections (F. esculentum, F. tetaricum) and five from Poland (Czernoplodna, Hruszowska, Jubilejna, Emka and Iskra) were cultivated under North Indian conditions and analysed for their protein and amino acid composition. The present studies revealed that European selections can also be successfully cultivated in India. Buckwheat is a good source of lysine, and some other essential amino acids.     

Sensory evaluation of and acceptability trials on biscuits prepared from raw and malted wheat (Triticum aestivum)-Bengal gram (Cicer arietinum) mixes with or without a green leafy vegetable

Biscuits were prepared by varying the amounts of the basic ingredients to arrive at the most acceptable recipe. The final recipe contained 40 g of mix, 40 g of jaggery and 20 g of ghee. Sensory evaluation of biscuits containing 5 or 10% colocasia leaf powder by composite scoring test and hedonic scale showed that the former type of biscuit was preferred over the latter. The acceptability trial conducted on 42, 3 to 6 year old children showed that biscuits from either malted mix with or without 7.5% colocasia leaf powder and raw mix were equally acceptable as shown by the analysis of variance.     

Amino acid composition protein quality and water-soluble vitamin content of germinated cowpeas (Vigna unguiculata)

Amino acid composition, protein digestibility, calculated protein efficiency ratio (C-PER and DC-PER), chemical scores and water-soluble vitamin content of cowpea seeds germinated at 25°C or 30°C for 24h were determined. Also, the effect of processing steps (heated-air drying, decortication and cooking) on these parameters were examined. Germination had little effect on amino acid profile of cowpeas. In vitro protein digestibility was not improved significantly by germination nor by decortication but was improved by cooking. C-PER and DC-PER ranged from 1.95 to 2.21 and from 1.63 to 1.82, respectively. DC-PER compared well withreported rat PER of cowpea products and seemed more sensitive than C-PER. Based on whole egg values, chemical scores ranged from 37.7 to 45.8% (mean±SD; 42.2±2.4%). Germination increased the contents of niacin, thiamin and riboflavin significantly. Decortication resulted in up to 30% loss in niacin while thiamin content was reduced 41% by cooking.     

Chemical composition and nutritional value of Mexican varieties of chickpea (Cicer arietinum L.)

Chemical composition and protein quality of the main chickpea varieties cultivated in Mexico were determined. The raw and cooked chickpeas analyzed were: Surutato, Surutato 77, Sonora, Sonora 80, Porquero, Macarena, Breve Duro and a mixture of broken seeds used mainly for animal feeding. The chemical composition of the raw chickpea studied was very similar; the average values of the nutrients were: ash 3.1±0.2, fat 5.0±1.0, protein 19.5±1.2 and fiber 3.7±2.1. Cooking diminished only the ash content and the Porquero variety was the only one that had a high content of crude fiber (9.1%). There was not found agglutinating activity to rabbit RBC in any of the raw chickpeas studied and the trypsin inhibitor activity average was 11.8±2.4 TUI/mg sample. Cooking destroyed 57% of this activity. Digestibility was the same in the raw and in the cooked chickpea (78%). There were not found significant differences in the PER values of the raw and cooked seeds: 1.65–2.30 and 1.80 to 2.61 respectively. The Surutato and Breve Duro varieties were statistically similar to the casein PER (2.5). It could be recommended to use these two varieties mainly for infant feeding.     

Relationship between amino acid scores and protein quality indices based on rat growth

Protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR) and relative NPR (RNPR) values, and amino acid scores were calculated for 20 food products (casein, casein + Met, beef salami, skim milk, tuna, chicken frankfurters, sausage, heated skim milk, peanut butter, rolled oats, soy isolate, chick peas, pea concentrate, kidney beans, wheat cereal, pinto bean, lentils, rice-wheat gluten cereal, macaroni-cheese, and beef stew). In most cases, PER, RPER, NPR or RNPR ranked the products in the same order and positive correlations among the protein quality methods were highly significant (r=0.98–0.99). Amino acid scores (based on the first limiting amino acid, Lys-Met-Cys, Lys-Met-Cys-Trp or lys-Met-Cys-Trp-Thr) were positively correlated to the PER, RPER, NPR or RNPR data (r=0.61–0.75). Inclusion of the correction for true digestibility of protein improved the correlations between amino acid scores and the indices based on rat growth. The correlations were especially high between Lys-Met-Cys scores (corrected for true digestibility of protein) and PER, RPER, NPR or RNPR (r=0.86–0.91). Inclusion of the correction for true digestibility of individual amino acids did not result in further improvements of the correlations in most cases. It is concluded that adjusting amino acid scores for true digestibility of protein would be sufficient and further correction for digestibility of amino acids would be unnecessary in mixed diets.This paper was presented in part at the 71st annual FASAB meeting, Washington, DC, March 29–April 2, 1987.     

Nutritional composition and antinutritional factors of chickpeas (Cicer arietinum L.) undergoing different cooking methods and germination

The effects of cooking treatments (boiling, autoclaving and microwavecooking) and germination on the nutritional composition and antinutritionalfactors of chickpeas were studied. Cooking treatments and/or germinationcaused significant (p < 0.05) decreases in fat, total ash, carbohydratefractions, antinutritional factors, minerals and B-vitamins. Germination wasless effective than cooking treatments in reducing trypsin inhibitor,hemagglutinin activity, tannins and saponins; it was more effective inreducing phytic acid, stachyose and raffinose. Cooking treatments andgermination decreased the concentrations of lysine, tryptophan, totalaromatic and sulfur-containing amino acids. However, cooked andgerminated chickpeas were still higher in lysine, isoleucine and totalaromatic amino acid contents than the FAO/WHO reference. The lossesin B-vitamins and minerals in chickpeas cooked by microwaving weresmaller than in those cooked by boiling and autoclaving. Germination resultedin greater retention of all minerals and B-vitamins compared to cookingtreatments. In vitro protein digestibility, protein efficiency ratio andessential amino acid index were improved by all treatments. The chemicalscore and limiting amino acid of chickpeas subjected to the varioustreatments varied considerably, depending on the type of treatment. Basedon these results, microwave cooking appears to be the best alternative forlegume preparation in households and restaurants.     

Relationship between total sulphur and sulphur amino acids in chickpea (Cicer arietinum L.) and pigeonpea (Cajanus cajan [L.] Millsp.)

Total sulphur was determined in seed meal of 30 chickpea and 24 pigeonpea cultivars by the wet digestion procedure and by using the Leco sulphur analyser. Methionine and cystine were determined after performic acid oxidation in an amino acid analyser. The two methods used for total sulphur determinations were highly correlated (r=0.943). Percent meal protein was significantly correlated (r=0.476) with total sulphur in chickpea but not in the case of pigeonpea. Total sulphur content exhibited a significant positive correlation (r=0.651) with sulphur amino acids of pigeonpea when expressed as percent of protein but not in the case of chickpea. Correlation coefficients between total sulphur and sulphur amino acids when the results were expressed as percent of sample were positive for both chickpea (r=0.494) and pigeonpea (r=0.534). The amount of sulphur in methionine and cystine accounted for 54.8% of the total sulphur in chickpea and for 75.5% in pigeonpea. In both chickpea and pigeonpea, methionine was positively and significantly correlated with cystine when they were expressed either as percent of sample or as percent of protein.Submitted as J.A. no. 159 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).     

椰麸组分蛋白的氨基酸组成、结构与乳化性分析

为提高椰子加工副产物的利用,本研究从椰麸中依次提取4种组分蛋白,包括清蛋白、球蛋白、谷蛋白-1和谷蛋白-2.分析这4种组分蛋白的氨基酸组成,并利用SDS-PAGE技术分析其亚基组成和分子量.同时分析其表面疏水性,并研究不同离子强度对椰麸各组分蛋白的乳化性和乳化稳定性的影响.结果表明,椰麸蛋白质中清单白、球蛋白、谷蛋白-...     

Estimation of optimum amino acid supplements to triticale

Based on the nitrogen balance (NB) data and the efficiency of amino acid utilization, optimum supplements of limiting amino acids (AA) to triticale were calculated and their effect on true N digestibility (TD), biological value of protein (BV) and net protein utilization (NPU) of a triticale-based diet was evaluated. To determine if AA balance must be considered in the calculation of the optimum supplements, the effect of a 20% of 40% excess of essential AA in lysine-, methionine-, threonine- or tryptophan-deficient diets was also studied. The AA excess had no significant effect on NB in diets deficient in lysine, methionine or threonine. However, NB in rats fed on the tryptophan-deficient diet increased as the AA excess increased. BV of the diet containing the optimized supplements of lysine, threonine, methionine and valine was comparable to that of lactalbumin or to the diet supplemented with all essential AA. The deletion of valine from the optimized supplement caused an insignificant decrease in BV. Due to the lower TD, NPU of diets containing the optimized AA supplements was lower than that of the diet containing all essential AA or of the lactalbumin-based diet.     

Chemical composition and nutritional potential of the tribal pulse (Bauhinia malabarica Roxb)

Proximate and mineral composition, seed protein fractions, amino acid composition, fatty acid profiles and antinutritional factors were analysed for the seeds of the tribal pulse,Bauhinia malabarica. The seeds contained higher amount of crude lipid when compared with most of the domesticated pulses. The seeds were rich in minerals like Ca, Mg and Fe. Glutelins (45%) constituted the major seed protein fraction followed by globulins which accounted for about 34%. Cystine and methionine were found to be the limiting essential amino acids; whereas tyrosine and phenylalanine content were fairly high when compared with WHO requirement pattern. The unsaturated fatty acids, oleic acid and linoleic acid, were predominant in seed lipids. Presence of antinutritional substances like total free phenols, tannins, L-DOPA and haemagglutinating activity also were analysed/assayed.     

Protein and amino acid composition of some wild leguminous seeds

The seeds of five different species ofAcacia, twoAlbizzia, twoErythrina and two species ofMucuna were analysed for their protein and amino acid composition. Some of these seeds are comparable to a popular food legume,Cicer arietinum, in protein and amino acid composition.     

Amino acid composition, available lysine content and in vitro protein digestibility of selected tropical crop seeds

As the search for alternative sources of food to alleviate hunger continues, this study was undertaken to determine nitrogen and amino acid content, chemical score, protein digestibility corrected amino acid score, available lysine and in vitro digestibility of 8 lesser known, wild tropical seeds, gathered in Nigeria. Results were contrasted with a tropical soybean variety (Glycine max, TGX 1660-15F). The investigated seeds wereMillettia thonningii, Gliricidia sepium, Lonchocarpus sericeus, Albizia zygia, Daneillia ogea andAfzelia bella from the family of Leguminosae,Diospyros mespiliformis (Ebenaceae) andEntandrophragma angolense (Meliaceae). The crude protein content, based on nitrogen determination, was found to be lower in the wild seeds compared to soybean, which was partly due to the relatively high content of non-protein nitrogen. With reference to amino acid requirement and digestibility in most seed samples, lysine, followed by sulphur amino acids and threonine, were the limiting amino acids. It was concluded, that these less familiar wild seed plants may be used as valuable food or feed complements. However, further investigation is necessary to elucidate potential toxic and antinutritional factors.     

Isolation and chemical evaluation of protein from water hyacinth

Leaf protein isolate from water hyacinth (Eichornia crassipes) was prepared and the chemical composition was studied. It contained 49.6% protein, 16.0% total lipids, 26.9% total carbohydrates, 1.7% fibre and 5.8% ash. Calcium, magnesium, copper, zinc, manganese and potassium were determined. Nutritional properties of the isolate are discussed in relation to its amino acid composition and to its in vitro digestibility by proteolytic enzymes. Comparison with the FAO/WHO reference pattern showed that all of the essential amino acids were present at high levels in the leaf protein isolate. The limiting amino acid in the isolate was methionine (i.e., methionine + cystine). In vitro digestibility was highest with digestion by pepsin followed by pancreatin and lowest with digestion by pepsin alone. Digestion with pancreatin alone gave intermediate values.     

Nutritional quality of chickpea (Cicer arietinum L.): current status and future research needs

The nutritional composition and the affects of processing and storage and anti-nutrients on nutritional value of chickpeas are reviewed. Future research needs are discussed.Submitted as J.A. No. 431 by the International Crops Research Institute for the Semi-Arid Tropics (ICRASAT).     

Nutritive value of rapeseed proteins and fractions supplemented with methionine and tyrosine in rats

Rapeseed protein concentrate (RPC), rapeseed 2S and 12S fractions, a blend of 2S and 12S fractions, retentate (RET) and precipitate (PRE) proteins obtained during rapeseed fractionation were compared to casein for nutritive value as determined by net protein ratio (NPR) and apparent digestibility coefficient (ADC). Tyrosine concentration in rapeseed 2S fraction was the lowest compared to all other protein sources and methionine was the first limiting amino acid. The NPR and ADC of RPC, RET, and fraction 12S did not change significantly (P<0.05) following supplementation with methionine, but for PRE the NPR was decreased significantly (P<0.05). However, the rapeseed 2S fraction supplemented with tyrosine had a NPR significantly (P<0.05) higher than that of RPC and not significant (P<0.05) different from that of casein. The NPR of the 2S and 12S blend was significantly (P<0.05) higher than that of RET and PRE; however, no significant (P<0.05) difference was observed in NPR and ADC of the blend when supplemented with tyrosine. The nutritive value and digestibility of rapeseed 2S fraction were improved by supplementation with tyrosine and by blending with the 12S fraction.