Preparation and antinutritional characteristics of dry bean (Phaseolus vulgaris L.) protein concentrates

Protein concentrates and starches were prepared by a wet extraction process from five dry bean (Phaseolus vulgaris L.) cultivars. The protein contents ranged from 69.7–76.4%. Concentrates prepared from dehulled beans under similar conditions had higher protein contents (80.6–87.9%). Each additional washing of the concentrates with distilled water increased their protein content. However, the protein recovery progressively decreased. The yield of starch ranged from 48.0–51.1% of the starting material. The solubility of bean proteins was minimal at pH 4.0, and under alkaline conditions, it was influenced by the tannin contents of the concentrates. Protein concentrates had lower trypsin, chymotrypsin, and amylase inhibitory activities as well as lower phytic acid and tannin contents compared to whole bean flours.     

Chemical characterization of high-yielding varieties of cashew (Anacardium occidentale)

Cashew apples and kernels from sixteen high-yielding varieties were chemically characterized. Protein, starch, amino acids and sodium contents in cashew kernels did not vary significantly among the high-yielding varieties. Reducing sugar content in the kernel was negligible compared to total sugar. Ascorbic acid, amino acid, phenol and tannin contents in cashew apple showed a significant variation among high-yielding varieties. Non-reducing sugar content in cashew apples was negligible. Varieties M 6/1, Bla 256-1, M 10/4 and M 44/3 appeared to be better for apple juice extraction because of their low tannin content. No varietal difference was noticed with respect to qualitative composition of sugars, organic acids and phenols.CPCRI Contribution No. 459     

The nutritive value of amaranth grain (Amaranthus caudatus)

The nutritional value of three pale seeded and one dark seeded variety ofAmaranthus caudatus was studied by chemical analyses and in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 14% protein, 10% fat, 2.5% ash, 64% starch and 8% of dietary fibre. The black seeds had a much higher content of fibre (16%). The concentration of essential amino acids were high. Lysine ranged from 5.2–6.0 g/16 g N in the grains, and the limiting amino acids were leucine followed by valine or threonine. The grains contained small amounts of tannin (0.3%) and heat-labile protease inhibitor activity, at levels typical of common cereal grains. Digestibility of protein in the pale seeds was high (87%) and quite unaffected by processing. Protein digestibility of the black seeds was lower, and the digestibility was further reduced by toasting. The biological value of the protein was similar in all products, and very high. The content of minerals varied among varieties and was also affected by processing. Phytate: zinc molar ratios were high in most products, and rats fed the amaranth samples with the lowest zinc contents were in negative zinc balance. In general, femur zinc concentrations were rather low. However, amaranth is an unconventional crop which deserves further attention.     

Influence of phytate on in vitro digestibility of casein under physiological conditions

The phytic acid content of four different varieties of beans under different processing conditions was estimated. It was highest in red kidney (1.86–2.13%) slightly lower in pigeon (1.86–2.03%), white (1.80–1.96%) and black eyed beans (1.15–1.64%). There was no significant change in phytic acid content of beans after soaking at 25°C for 22 hours. However, both soaking and cooking revealed 26–37% loss of phytic acid in all four varieties of beans.The rate of in vitro casein digestibility with and without phytic acid at concentrations found in legumes was determined at pH 8 and 37°C using multienzyme technique. Addition of 5 mg Na-phytate reduced the casein digestibility up to 20% compared to the control. However, only 25% reduction of casein digestibility was observed in the presence of 25 mg of Na-phytate. Higher concentration of Na-phytate had no significant effect on the rate of casein digestibility. Data strongly suggest the formation of protein phytate complex at alkaline pH of small intestine.Part of this work was presented at the XIII International Congress of Nutrition in Brighton, UK in August 1985.     

Nutritive quality and energy yield of high oil,opaque-2 and waxy maize hybrids compared to normal maize hybrids

Grain yield, chemical composition, protein quality and digestible energy were measured for 18 maize varieties (opaque-2, high oil, waxy hybrids, normal hybrids) cultivated in Yugoslavia. Protein quality assessment was based on amino acid composition, and true protein digestibility, biological value, net protein utilization and utilizable protein as determined in nitrogen balance experiments with rats. The protein concentration in dry matter varied from 8.63–18.81% while the fat concentration varied from 4.45–16.13%. There were only minor differences in ash and crude fibre, while starch and sugar varied inversely to fat and protein concentration. Lysine levels were approximately 30% higher for the opaque-2 varieties compared with normal maize, while leucine levels were about 30% lower. Yields were extremely high for all varieties with the highest value being 10.3 tonnes/ha. Due to the high yields, protein production/ha was high in range of 822–977 kg. This resulted in high yields of amino acids/ha. Protein utilization was very high in the opaque-2 varieties, which had the highest lysine contents. The biological values were close to 80 in these varieties, whereas they were only 60–65 in the normal maize varieties.     

Nutritional evaluation of some commercial wheat varieties grown in Pakistan

The nutritive value of some commercial wheat varieties grown in Pakistan was measured chemically, including amino acid analysis, and biologically in N-balance experiments with growing rats. The protein content ranged from 13.2% in Punjab-83 to 16% in Barani-83. Lysine per 100g protein varied between 2.46 and 2.75%. The available carbohydrate ranged from 67.3 to 74.7%. Iron content was highest in Sonalika while the concentration of zinc and manganese was highest in Sarhad-82. The protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) varied between 92–95%, 56–68% and 53–65% respectively. Level of wheat protein was negatively correlated with available carbohydrate (r=–0.93), lysine per unit protein (r=–0.67) and BV (r=–0.76). The lysine content (g/16gN) of commercial wheat varieties showed a positive correlation (r=+0.95) with the BV. The protein quality was lowered in varieties having higher content of protein.     

Preparation and properties of flours and protein concentrates from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds

In vitro protein digestibility, chemical composition and selected functional properties of flours and protein concentrates prepared from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds were studied. Protein concentrates prepared by an alkaline extraction process had increased crude protein contents (61.5–70.8%) compared to flour samples (46.4–52.7%). The yields of protein concentrates ranged from 24.5% to 29.4% while values for protein recoveries varied between 64.8% and 65.2%. Protein concentrates also had increased foam volume and decreased foam stability (100% decrease over a 2 h period), compared to flour samples. Fermentation and germination were observed to significantly (p<0.05) lower polyphenol and phytic acid contents, but increased protein digestibility of fluted pumpkin seed flours and concentrates. Both raw flour and concentrate were significantly (p<0.05) higher in water absorption capacity than germinated or fermented flours and concentrates. Protein concentrates had comparatively better fat absorption properties than the flour samples. Hence protein concentrates may prove to have useful applications in ground meat formulations.     

Proximate composition and mineral content of selected Tanzanian vegetables and the effect of traditional processing on the retention of ascorbic acid,riboflavin and thiamine

Proximate composition, mineral content and the effect of traditional processing practices on the retention of ascorbic acid, riboflavin and thiamine were studied using amaranth, cowpea, peanut, pumpkin and sweetpotato leaves. Results of this study indicated that, crude protein, crude fat, carbohydrate and ash contents were in the range of 20.64–46.56 percent, 2.57–4.34 percent, 35.43–63.50 percent and 8.92–15.69 percent respectively. The mineral content per 100 g of fresh vegetables was in the range of 83.64–229.34 mg, 145.97–780.19 mg, 11.56–21.31 mg, 43.02–110.30 mg, 0.96–5.90 mg and 0.40–2.24 mg for Ca, K, Na, Mg, Fe and Zn respectively. For ascorbic acid, riboflavin and thiamine, concentrations in 100 g of fresh vegetables were in the range of 43.78–89.00 mg, 0.62–1.71 mg and 0.09–0.30 mg respectively. The traditional processing practices of sun/shade drying and storing in ventilated containers resulted in a significant (P<0.05) decrease in ascorbic acid, riboflavin and thiamine for all vegetables. Conventional blanching and cooking for up to 15 minutes resulted in a significant (P<0.05) increase in riboflavin content in cowpea, peanut and pumpkin greens while in amaranth and sweetpotato leaves, thermal processing resulted in a significant (P<0.05) decrease in the vitamin. Based on the results of this study, the vegetables were good dietary sources of minerals, carbohydrate and protein.     

Fatty Acid Composition of Three Rice Varieties Following Storage

The petroleum ether extractable lipids (PEE-L) and aqueous propan-1-ol extractable lipids (PWE-L) of three varieties of rice were determined gravimetrically and characterised by fatty acid profiles. The content of PEE-L (22·5–28·2 mg g⁻¹) was higher than that of PWE-L (7·4–11·5 mg g⁻¹) in brown rice with the situation reversed in milled rice (3·0–4·5 mg g⁻¹vs. 7·2–8·7 mg g⁻¹). The ratio of unsaturated fatty acid to saturated fatty acid was about two times higher in PEE-L than that in PWE-L for both brown and milled rice reflecting the selective complexation of saturated fatty acids. Rice storage at 37 °C resulted in some minor but statistically significant changes in the fatty acid profile. In the case of brown rice, the only notable changes were a reduction in the amounts of oleic and linoleic acids in the aqueous propan-1-ol extractable fatty acid fraction (PWE-FA) following storage at the higher temperature. Milled rice of all three varieties showed a decrease in linoleic acid content of PEE-L following storage at 37 °C for 4 and 7 months compared to storage at 4 °C. There was no change in fatty acid contents of PWE-L of milled rice when stored at 4 and 37 °C for 4 and 7 months. This implies that the PWE-L (or bound lipids) were more stable than PEE-L (or free lipids) during storage.     

Seed protein fractions and amino acid composition in gram (Cicer arietinum)

Six chickpea strains were analysed for their protein content and various protein fractions. The protein content ranged from 20.9–25.27%. Albumin, globulin, prolamin and glutelin contents ranged from 8.39–12.31%; 53.44–60.29%; 3.12–6.89% and 19.38–24.40% respectively. Salt soluble proteins (albumin + globulin) and globulins resolved into 19–23 bands whereas albumin proteins resolved into 30–34 bands. The molecular weights of various polypeptides ranged from 10–91 kD. Amino acid analysis of total proteins revealed that glutamic acid was present in maximum concentration followed by aspartic acid and arginine. Just like other pulse proteins, chick pea proteins were also found deficient in sulphur containing amino acids.     

湖北省三个油茶主栽品种的授粉品种选择研究

油茶是中国第一大木本食用油料树种。油茶自交结实率低,合理配置授粉品种是提高产量的关键之一。为筛选湖北主栽油茶品种（长林4号、鄂油81号及鄂油102号）合适的授粉品种,促进高产优质栽培,以长林3号、长林4号、长林40号、鄂油81号和鄂油102号为授粉品种,设计人工授粉组合,以自然授粉为对照,测定分析授粉后的坐果率和果实性状,筛选适宜的授粉品种。长林4号和鄂油81号的自交坐果率很低,鄂油102号的自交坐果率较高。授粉品种对坐果率有显著影响。授粉品种对长林4号的单果鲜重、干果出籽率、干籽出仁率、种仁含油率及油酸含量无显著影响,对坐果率和果实大小有显著影响;授粉品种对鄂油81号的干果皮厚度、干籽出仁率及种仁含油率无显著影响,对坐果率、果实大小和单果鲜重有显著影响;授粉品种对鄂油102号的坐果率、干果皮厚度、干果出籽率及种仁含油率有显著影响,对其它性状无显著影响。综合坐果率和果实性状,认为长林4号的最佳授粉品种为长林3号,其次是长林40号和鄂油102号;鄂油81号的授粉品种宜选择长林4号和鄂油102号;鄂油102号的最佳授粉品种为鄂油81号,其次是长林3号、长林4号及长林40号。     

Effect of processing and storage on the ascorbic acid (vitamin C) content of some pineapple varieties grown in the Rivers State of Nigeria

Ascorbic acid contents of the juice of four different pineapples species grown in the Rivers State of Nigeria were determined before and after storage of whole pineapple and processing and storage of the juice for two months. Ascorbic acid of the fresh juice ranged from 22.5 mg to 33.5 mg/100 g sample. After storage at room temperature (30–32 °C) of whole pineapple for two weeks, ascorbic acid was reduced to between 59 and 65 percent of the fresh juice. Processing the juice by pasteurisation reduced the ascorbic acid to between 28 and 46 percent while storage in plastic bottles for two months further reduced the ascorbic acid content to between 10 and 21 percent.     

Nutritional assessment of yam (Dioscorea alata) tubers

The nutrient and antinutrient components of tubers from seven cultivars ofDioscorea alata were determined. The average crude protein content ofD. alata tubers was 7.4%. Starch (75.6–84.3%) was the predominant fraction of the tuber dry matter. Significant differences in crude protein and starch contents were observed among cultivars. Vitamin C content of the yam tubers ranged from 13.0 to 24.7 mg/100 g fresh weight. The results showed yams to be reasonably good sources of minerals. Phytic acid contents of the yams were low, with values ranging from 58.6 to 198.0 mg/100 g dry matter. Total oxalate levels in yam tubers were found to be in the range of 486–781 mg/100 g dry matter, but may not constitute a nutritional concern since 50–75% of the oxalates were in the water-soluble form. The overall results are suggestive of the nutritional superiority of yams compared to other tropical root crops.     

Nutrient composition and biological evaluation of mesta (Hibiscus sabdariffa) seeds

Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.     

Proximate composition and functional properties of four cultivars of bambara groundnut ( Voandezeia subterranea)

Proximate composition and selected functional properties of four cultivars of bambara groundnut ( Voandezeia subterranea Thoura) were ascertained. Crude protein ranged from 17.5 to 21.1 percent; crude fat 7.3–8.5 percent; total ash 4–5 percent; crude fiber 1.8–2.0 percent; carbohydrate and moisture content for the different cultivars were 53.0–60.8 percent and 7.5–12.3 percent, respectively. The results of functional property determinations indicated that the bulk density ranged from 0.65 to 0.75 g/ml; water binding capacity 2.1–2.9 g/2g sample; oil binding capacity 0.9–1.6 g/2g sample; emulsifying activity 55.-1–60.0 percent and emulsifying stability 10–12 percent. The results show that bambara groundnut has great potential for incorporation into various human foods where it could provide useful plant proteins.     

Protein quality traits of vegetable and field peas: Varietal differences

Four high yielding varieties of field (Rachna and RFP₄) and vegetable peas (Bonnivielle and Arkal) were studied for their protein quality. Crude protein and true protein content of all four pea varieties varied from 19.5 to 20.6 percent and 18.7 to 19.8 percent, respectively. Non protein nitrogen formed only 3.94 to 4.84 percent of total nitrogen. Globulins were the major fractions followed by albumins and glutelins. All the four varieties of peas had similar methionine and tryptophan content. Lysine content of four pea varieties ranged from 7.56 to 9.65 g per 16 g of N. Cooking brought about an increase in in vitro protein digestibility of peas by 10 percent. The sodium dodecyl polyacrylamidegel electrophoresis of total protein revealed the presence of 22–25 bands with some difference in banding pattern of all four varieties. Some differences were observed in banding patterns of globulin and albumin of all four varieties, suggesting that composition of protein of pea varieties differed.     

Oil and protein quality of groundnut mutants

Variability in oil quality was observed in four groundnut mutants (TG-1, TG-3, TG-14, TG-16) induced by -irradiation. The fatty acid composition of the mutants differed from their parent Spanish Improved. All the mutants had lower linoleic and higher oleic acid than the parent Spanish Improved. TG-3 and TG-14 had substantially higher linoleic acid and lower oleic acid as compared with TG-1 and TG-16. Other fatty acids also showed minor variation amongst mutants and Spanish Improved. The ratio of oleic to linoleic acid, which is an index of oil stability, was 2.7 and 3.3 fold respectively in TG-16 and TG-1 as compared with Spanish Improved.Protein percent in TG-1, TG-14 and TG-16 was higher than in Spanish Improved. Amino acid analysis of protein from mutants indicated decreases in methionine and cystine and an increase in tryptophan as compared with Spanish Improved. Other amino acids did not show any major variation between the mutants and Spanish Improved. In all varieties except TG-16, lysine was the first limiting amino acid; threonine was second limiting in all mutants. The essential amino acid content per kernel was higher in mutants than in Spanish Improved.     

The toxicants and phosphorus content of some Nigerian vegetables

The oxalate, hydrocyanic acid, phytic acid and phosphorus contents of twelve leafy vegetables were determined. The values ranged from 47.7–194.3 mg/100 g DM, 4.32–23.8 mg/100 g DM, 90–260 mg/100 g DM and 215–1110 mg/100 g DM, respectively. The ratio of phytic acid to phosphorus ranged from 13.9–90.7. The leaves contained low levels of hydrocyanic acid, while the oxalate, phytic acid and phosphorus contents were high. The results are discussed in terms of their clinical implications and nutritive values.     

Difference of Phytic Acid Content and its Relation to Four Protein Composition Contents in Grains of Twenty-nine japonica Rice Varieties from Jiangsu and Zhejiang Provinces, China

Twenty-nine japonica rice varieties collected from Jiangsu and Zhejiang Provinces, China were planted in Hangzhou, China, to investigate the phytic acid content in brown rice and its frequency distribution as well as the correlation among the contents of phytic acid, total protein and four protein compositions in brown rice. The phytic acid content in brown rice ranged from 0.699% to 1.034%, with a mean of 0.868% for the 29 tested rice varieties. Xiushui series rice varieties generally exhibited lower phytic acid level than Wuyujing and Huai series rice varieties. A rough normal distribution, with a mean of 8.722%, was observed for the total protein contents in the tested varieties. Of the four protein compositions, the glutelin, globulin and albumin contents had larger coefficient of variation than the prolamin content, although the difference in prolamin content was genotype-dependent. No significant correlation was found between the phytic acid and four protein composition contents, whereas the total protein content was significantly and positively related to the glutelin content in brown rice.     

啤酒大麦与饲用大麦籽粒结构和淀粉粒的比较研究

为了探索大麦籽粒结构和淀粉粒与其用途的关系，利用扫描电子显微镜（SEM）和差示扫描量热分析仪（DSC）对啤酒大麦（港啤1号和扬农啤2号）与饲用大麦（扬饲麦1号）的籽粒结构和淀粉粒进行了比较研究。结果表明，3个品种表现相似的胚乳结构，但啤酒大麦的淀粉粒与蛋白质结合不紧密，饲用大麦的淀粉粒和蛋白质结合较紧密，且饲用大麦的蛋白质基质含量高于啤酒大麦。采用碱处理和差速沉淀法分离了籽粒胚乳大、中、小淀粉粒，虽然品种间淀粉粒的形态无明显差别，但大、中、小淀粉粒的大小和含量差异很大。DSC分析所得参数表明，大淀粉粒糊化时的起始温度（To）、峰值温度（Tp）和终结温度（n）高于相同品种的中、小淀粉粒，且糊化过程所需的热焓（△H）也较高。