Protein quality of some Nigerian feedstuffs. I. Chemical assay of nutrients and amino acid composition

The nutrient and amino acid composition of a range of Nigerian feedstuffs were studied by chemical analysis and column chromatography for amino acids. Nearly all feedstuffs studied showed low crude fibre value except the palm kernel meal and the African locust bean seeds which gave high values, range 8.1 to 12.3% and 8.76 to 12.64%, respectively. All the animal protein concentrates studied, namely, skim milk powder, blood meal and fish meal showed desirable feedstuff characteristics such as a low crude fibre content, high crude protein content and fairly high gross energy values, lysine, methionine and tryptophan were the amino acids in shortest supply in most of the feedstuffs.     

Some aspects of the biochemistry and nutritive value of the water melon seed (Citrullus vulgaris, Schrad).

The proximate composition, amino acid profile of the protein, mineral and fatty acid constituents of melon seed were studied by chemical analysis, column chromatography for amino acids and gas chromatography for fatty acids. Two hundred and sixteen, male weanling albino rats of the Wistar strain, 28–30 days old and weighing on the average 50–55 g were used in three experiments to study the protein quality of melon seed meals with and without amino acid supplementation. The raw and fried undefatted melon seed meals (RUM and FUM), had crude protein and fat contents of between 31–37% and 54–57%, depending on the variety, while the raw and fried defatted meals (RDM and FDM) had 69–78% and 1.1–2.7% respectively. Crude fibre levels were low in all samples. Melon seed contained high amounts of Ca, P, Mg, K, Zn and Fe. The fat comprised the following percentage acids: linoleic (52.3–57.9), oleic (13.6–21.7), palmitic (11.1–18.6), and stearic (13.0–16.8). The fairly high iodine value (113.1–118.7) and saponification number (192.8–194.6) confirmed the unsaturated nature of the melon seed oil. Lysine and methionine were the amino acids in shortest supply while threonine was marginal. The tryptophan content (2.21 g/16 g N) was higher than in most other plant protein sources. In studies with rats, the true digestibility of RUM, FUM, RDM and FDM were similar (range, 91–93%) and were comparable to that for soyabean meal (SBM), (91.74%), but lower than for whole hen's egg (WHE), (98.8%). RDM and FDM had superior protein quality indices compared to RUM and FUM. RUM, RDM, FUM, and FDM had p.e.r., n.p.r., n.p.u. and b.v. of 0.33, 1.53, 41.30 and 46.84; 0.93, 2.58, 49.74 and 52.84; 0.75, 2.02, 44.64 and 48.79; and 1.01, 2.67, 50.12 and 54.18 respectively, which were significantly (P<0.05) inferior to those for SBM and WHE (1.91, 3.89, 61.33 and 65.85; and 4.77, 6.14, 94.86 and 96.94). Feeding FDM at increasing protein levels (10, 15, and 20%) resulted in increasing liveweight gains, improved p.e.r. up to 15%, but did not significantly alter the n.p.u. and b.v. Amino acid supplementation of 10% protein FDM diet, confirmed that lysine is the most limiting amino acid in melon seed meal for rat growth, followed by methionine and threonine. The levels of tryptophan and isoleucine were found to be adequate.     

Nutritional value of mixtures of baladi bread and broad beans

Several supplementation mixtures to the local Egyptian bread were designed and tested for their p.e.r. and n.p.u. values using weanling rats. In the first experiment, broad beans (var. baladi) were subjected to five different methods of preparation and each of the products was added to bread-based diets at 50 : 50 nitrogen ratio. When the p.e.r. (1.78) and n.p.u. (53) values of the raw beans were set as 100 and 100, the respective following values are obtained: 94, 98 for soaked; 94, 87 for germinated followed by boiling and 59, 79 for autoclaved beans (1 h). In the second experiment 11 different protein mixtures were tested for their p.e.r. values. The tested protein mixture with the lowest p.e.r. value is that from bread + 0.5% DL-Met (p.e.r. = 1.3). The most favourable mixture found is bread + Met + Lys + Thr (p.e.r. = 3.3) to bring it to level furnished by whole egg, followed by the mixtures bread N and raw broad bean N 40:60 (p.e.r. = 3.0); bread N and stewed broad bean N 70:30 (p.e.r. = 2.8). Upon supplementation with 0.5% DL-Met mean p.e.r. values of 3.0 and 2.7 were obtained for raw and stewed broad beans diets, respectively. The amino acid analyses showed losses of 10 and 35% in the lysine and S-containing amino acids, respectively, after autoclaving the beans for 1 h.     

人造腰果酥饼的研制

人造腰果酥饼是以花生、核桃、杏仁为主要原料,适当添加乳化剂、泡打粉、白砂糖等辅料用微波烘烤而成。其风味近似于腰果,组织酥脆,口感香甜,营养价值高,是一种理想的腰果替代品。     

Chemical and biological evaluation of protein quality of locally produced and processed full-fat soya bean flour from three Tanzanian villages

Samples of locally produced and processed full-fat soya bean flour from three Ujamaa villages in Tanzania were tested for protein quality and trypsin inhibitory activity. Differences were found in true digestibility (t.d.), biological value (b.v.) and net protein utilisation (n.p.u.) of the three flours as tested in balance experiments with rats under standardised conditions. A possible explanation for the differences is suggested on the basis of variations in amino acid content and trypsin inhibitory activity. The possible reasons for the variation in inhibitory activity are discussed.     

人造腰果酥饼工艺

人造腰果酥饼是以花生、核桃、杏仁为主要原料,适当添加乳化剂、泡打粉、白砂糖等辅料微波烘烤而成。其风味近似于腰果,组织酥脆,口感香甜,营养价值高,是一种理想的腰果替代品。     

Functional Properties of Flax Seed Mucilage

Flax seed (Linwn usitatissimum L.) mucilage was prepared by extraction of seeds with water followed by evaporation, precipitation with ethanol and freeze drying of extract. Proximate composition, solubility, foamability and moisture sorption characteristics were determined. The mucilage contained less carbohydrates, more minerals and more protein than commercial locust bean and guar gums. Its solubility, however, was higher than locust bean and guar gums, and lower than gum arabic. Flax seed mucilage exhibited good foam stability properties in aqueous solutions at 1.0% (w/v). Very diluted solutions exhibited Newtonian-like behavior while shear thinning was shown at concentrations above 0.2% (w/v). The viscosity was maximum at a pH range 6.0–8.0 and it was reduced in solutions containing NaCl.     

Nutritional quality and protein value of exotic almonds and nut from the Brazilian Savanna compared to peanut

The aim of this study was to determine the nutritional quality and protein value of the baru almond, pequi almond, and cerrado cashew nut compared to the peanut. We determined the proximate chemical composition, mineral content, and amino acid profile. A biological assay was carried out to assess the protein value, by net protein ratio (NPR), relative net protein ratio (RNPR), and protein digestibility-corrected amino acid score (PDCAAS) indexes. We found that the exotic almonds and the nut are rich in proteins (22.7-29.9 g/100 g), lipids (41.9-50.0 g/100 g), fibres (baru and pequi almonds, around 10.0 g/100 g), iron and zinc (4.3-7.4 mg/100 g). Baru almond's protein did not show deficiency in essential amino acids and lysine was the first limiting amino acid in the proteins of the pequi almond and cerrado cashew nut. The baru almond showed a RNPR of 86%, similar to that of the cerrado cashew nut (78%), but higher than that of the peanut (72%) and of the pequi almond (54%). The PDCAAS value of the baru almond (91%) was the highest and cerrado cashew nut and peanut presented similar values of this index (82%), which were higher than that of the pequi almond (55%). The baru almond has the highest protein quality, but the cerrado cashew nut and peanut are sources of good quality protein, too. We recommend the inclusion of these exotic foods in healthy diets and in food industry, and the baru almond and cerrado cashew nut as sources of complementary protein.     

Analysis of mesocarp and kernel oils from the American oil palm and F1 hybrids with the West African oil palm

The mesocarp oil of the American oil palm is more unsaturated than that of the West African oil palm. Mesocarp oils obtained from F₁ hybrids of these two oil palms exhibit an intermediate degree of unsaturation. Hybrid kernel oils are similar in composition to that of their West African oil palm parent, whereas kernel oils from the American oil palm are considerably more unsaturated and exhibit a unique fatty acid composition among seed fats of the Palmae family.     

Composition and protein quality of sweet lupin seed

The proportion of seed coats (hulls) of four varieties of sweet lupin seeds ranged from 19 to 25%. The amount of hull varied inversely with the weight of the seed, within each variety. Lupinus luteus cv Weiko III had 40.1% protein (dry basis); of 3 cultivars of L. angustifolius cv Uniharvest had the highest protein (36.2%), while cv Uniwhite had the lowest (28.6%). The protein content of dehulled lupins was about 20% higher than that of the whole seeds. L. angustifolius cv Uniwhite and L. luteus cv Weiko III were analysed for moisture, protein, lipid, ash, fibre, amino acids, carbohydrates, calcium, phosphorus, zinc, iron, copper and manganese. Whole seed, hulls and kernels were examined. Sulphur amino acids were limiting. The protein efficiency ratios of the two varieties, supplemented with methionine, were 2.40 and 2.56, respectively; these values increased by about 10% when the protein of the dehulled lupin seeds were tested. The requirement for added methionine for maximum p.e.r. was 0.65 g/kg diet. When dehulled lupin seed was steeped in water for a day and boiled and included in the diet of rats, slightly superior growth and p.e.r. resulted. The two varieties of dehulled lupin seeds effectively supplemented the protein of barley meal in the diet of rats, especially when methionine supplements were added, but were less efficient in supplemental value than was casein.     

Optimization of the Acceptance of Prebiotic Beverage Made from Cashew Nut Kernels and Passion Fruit Juice

The aim of this research was to develop a prebiotic beverage from a hydrosoluble extract of broken cashew nut kernels and passion fruit juice using response surface methodology in order to optimize acceptance of its sensory attributes. A 2² central composite rotatable design was used, which produced 9 formulations, which were then evaluated using different concentrations of hydrosoluble cashew nut kernel, passion fruit juice, oligofructose, and 3% sugar. The use of response surface methodology to interpret the sensory data made it possible to obtain a formulation with satisfactory acceptance which met the criteria of bifidogenic action and use of hydrosoluble cashew nut kernels by using 14% oligofructose and 33% passion fruit juice.     

Extracellular proteinases ofBacillus spp. isolated from fermented African locust bean,Iru

Extracellular proteinase production by seven strains ofBacillus subtilis group isolated from fermented African locust bean was compared. The seven strains, which were designated BS1, BS2, BS3, BL1, BL2, BL4 and BP2, showed significant differences (α = 0·05) in extracellular proteinases production. The order of proteolytic activity (in descending order) of the strains in nutrient broth medium containing African locust bean was: BL2 > BP2 > BS2 > BL4 > BS3 > BL1 > BS1. The proteinases of strains BL2 were purified and characterized by ammonium sulphate precipitation, ion-exchange chromatography. Three proteinases (serine proteinase, neutral proteinase and an esterase) were identified with MW of 18·2–19·7, 22·6 and 33·5 kDa, respectively. The serine proteinase was highly hydrophobic while the esterase was characterized by low specific activity.     

Functional properties of raw and heat processed cashew nut (Anacardium occidentale, L.) kernel protein isolates

The functional properties viz. solubility, water and oil absorption, emulsifying and foaming capacities of the protein isolates prepared from raw and heat processed cashew nut kernels were evaluated. Protein solubility vs. pH profile showed the isoelectric point at pH 5 for both isolates. The isolate prepared from raw cashew nuts showed superior solubility at and above isoelectric point pH. The water and oil absorption capacities of the proteins were slightly improved by heat treatment of cashew nut kernels. The emulsifying capacity of the isolates showed solubility dependent behavior and was better for raw cashew nut protein isolate at pH 5 and above. However, heat treated cashew nut protein isolate presented better foaming capacity at pH 7 and 8 but both isolates showed extremely low foam stability as compared to that of egg albumin.     

Rapeseed meal. IV. Continuous water extraction and short-term feeding studies in rats with the detoxified product

A continuous two-hour water extraction procedure is proposed instead of the former 14-hour method to remove the thioglucosides from rapeseed presscake meal (RSM). This new procedure produced a complete removal of isothiocyanates (ITC) and a reduction of 97% in oxazolidinethiones (VTO). Net protein utilisation (n.p.u.) increased from 40 to 69% and protein efficiency ratio (p.e.r.) from 0.8 to 1.94. The detoxified material showed a satisfactory growth-promoting capacity for the rat at the level of 10% dietary protein. It did not cause hypertrophy of the thyroid, as compared to the untreated meal, but it produced histopathological damage of variable intensity to this gland. It also caused a slight increase in the size of the liver although the histology of this organ does not show signs of damage. The importance of the minimal residual VTO content in the washed rapeseed meal upon the effect of thyroid histology is discussed and the presence of substances other than VTO and ITC which could be responsible for such adverse effects is postulated.     

霉变大豆对豆粕质量的影响

大豆霉变后，营养物质含量减少，籽粒变色变味，某些微生物分泌的毒素富集在大豆上可能使籽粒感染上毒素。通过对霉变大豆含量不同的大豆样品和豆粕样品进行油脂含量、粗蛋白含量、氢氧化钾蛋白质溶解度、尿素酶活性、色泽和气味等质量指标的测定，分析和研究霉变大豆对豆粕质量的影响。结果显示，随着霉变大豆含量的增加，豆粕粗蛋白含量有所升高，豆粕氢氧化钾蛋白质溶解度降低，豆粕尿素酶活性降低，豆粕颜色灰暗无光泽，霉变味加重。由此得出。用豆粕蛋白质含量作为评价霉变大豆加工所得豆粕质量的指标是不合适的，而采用豆粕氢氧化钾蛋白质溶解度作为评价指标更为合理。这一结果应在大豆油脂生产和豆粕贸易中受到重视。     

Study of emulsions stabilized with Phaseolus vulgaris or Phaseolus coccineus with the addition of Arabic gum, locust bean gum and xanthan gum

The properties of o/w emulsions stabilized with 1%w/v common bean (Phaseolus vulgaris L.), V or scarlet runner bean (P. coccineus L.), Coc extracted by isoelectric precipitation or ultrafiltration, at pH 7.0 and 5.5, with the addition of Arabic gum, locust bean gum, xanthan gum and a mixture of xanthan gum–locust bean gum (0.1 %w/v and 0.25 %w/v) are studied. The stability of emulsions was evaluated on the basis of oil droplet size, creaming, viscosity and protein adsorption measurements. The addition of Arabic gum, caused an increase in D[4,3] values and a decrease in the amount of protein adsorbed at the interface. The addition of locust bean gum in some emulsions reduced the amount of protein adsorbed. The addition of xanthan and to a less extend of the polysaccharide mixture, promoted a decrease in D[4,3]. So, emulsion stability was affected by the polysaccharide nature. Differences were also observed with respect to the protein nature, the method of its preparation and emulsion's pH. All polysaccharides enhanced the emulsions viscosity with xanthan and xanthan–locust bean gum exhibiting the higher values. V isolates and isoelectricaly precipitated isolates of both V, Coc showed higher viscosity values. The stability was enhanced by the increase of the viscosity of the continuous phase and the creation of a network, which prevents the oil droplets from coalescence.     

Domestication of Irvingia gabonensis: 4. Tree-to-tree variation in food-thickening properties and in fat and protein contents of dika nut

Dika nut kernels were extracted from the nuts of 24 Irvingia gabonensis fruits collected from 151 trees in three villages in Cameroon and Nigeria. Methods were developed for the milling, de-fatting, hot-water pasting and rapid visco-analysis of the samples, to simulate the cooking of dika nut meal as a food-thickening agent. Two parameters (viscosity and drawability), thought to relate to the soup-thickening quality of dika nut meal, were derived from the traces. The samples exhibited significant tree-to-tree variation in viscosity, drawability and fat content, and differences between their villages of origin were significant. Thickening was found not to be directly associated with protein content. Similarly, the fat content did not contribute to the thickening properties at temperatures above fat melting point. Fat determination and fatty acid profiling indicated that the fat content ranged from 37.5% to 75.5% and identified myristic and lauric acids as the major fatty acid components. This study is part of a wider tree domestication project characterising tree-to-tree variation in fruit, nut and kernel traits of I. gabonensis with the aim of improving the livelihoods of subsistence farmers.     

A survey of the bacteriological quality of preroasted peanut, almond, cashew, hazelnut, and brazil nut kernels received into three Australian nut-processing facilities over a period of 3 years

There is little information about bacteriological quality of preroasted kernels available in the public domain. An investigation of the bacteriological quality of preroasted peanut, almond, cashew, hazelnut, and Brazil nut kernels received into three Australian nut-processing facilities was performed over a period of 3 years. A total of 836 samples were analyzed for aerobic plate count, and 921 samples for Salmonella and Escherichia coli. The 921 samples included 653 peanut, 100 cashew, 60 almond, 60 Brazil nut, and 48 hazelnut kernels. There was no E. coli detected in any sample. Salmonella subsp. II (Fremantle) was detected in one raw almond sample. The aerobic plate count percentages of positive samples with counts above the detection level of the plating method used (100 CFU/g) for peanuts, almonds, cashews, hazelnuts, and Brazil nuts were 84, 78, 74, 50, and 45%, respectively. Of the samples containing more than this detection limit, the means were 4.5, 4.4, 3.1, 2.5, and 3.8 log CFU/g respectively. Although roasted kernel quality was not within the scope of this survey, raw microbial bioload would be expected to reduce on roasting. The bacteriological quality of preroasted peanut, almond, cashew, hazelnut, and Brazil nut kernels received into nut-processing facilities in Australia does not appear to suggest a public health concern.     

Cashew nut oil: effect of kernel grade and a microwave preheating extraction step on chemical composition,oxidative stability and bioactivity

The cashew nut kernels can be broadly classified by colour, size, quality and integrity, into whole (W), butts (B), splits (S) and P (pieces). This work evaluated seven sizes and qualities of cashew kernel (B1, S1, W4, SP1, SP2, P2 and W240), for oil extraction. Then, two oil extraction methods, using cold pressing (CP) and microwave preheating (MP), respectively, were investigated. In evaluation of cashew kernel grades, the fat content varied between 51.6 and 57.6 g 100 g^?1, and the acidity and peroxide were low, indicating good chemical quality for all grades. The oil extracted by MP showed a higher induction time in the Rancimat test (46.25 h). The cashew nut oil showed bioactivity, mainly associated with the level of total phenolic compounds (CP: 202.17 mg 100 g^?1; MP: 371.95 mg 100 g^?1), and showed antiproliferative activity against cancer cells (lung, breast and liver) but only at high concentrations. The MP extraction preserved many components and increased the phenolic compounds in the cashew kernel oil, without promoting negative changes in its physicochemical and oxidative qualities.     

Surface tension of Phaseolus vulgaris and coccineus proteins and effect of polysaccharides on their foaming properties

The surface tension of protein isolates from common bean (Phaseolus vulgaris L.) and scarlet runner bean (Phaseolus coccineus L.), prepared by isoelectric precipitation and ultrafiltration was evaluated, with respect to protein concentration (0.001–0.1% w/v) and pH (pH 4.5, 5.5, 7.0 and 8.0). Surface tension was most reduced, and with a higher rate of reduction at higher protein concentration and at pH 8.0. Foams (1, 2% w/v protein), at the same pH values, with and without the addition of polysaccharides, were studied. The proteins’ foaming behaviour was related to their adsorption behaviour. Arabic gum, locust bean gum (0.1% and 0.25% w/v), xanthan gum and a xanthan/locust bean gum mixture (0.1% w/v) had a positive effect on foam creation. All polysaccharides increased foam stability, probably due to the viscosity increase and to the creation of a network, which prevents the air droplets from coalescence. Isolates from P. coccineus and isolates obtained by ultrafiltration seemed to exhibit better foaming properties.