Amino acid profile of the seed and other parts of the winged bean

The chemical composition of the seeds and other parts of the winged bean shows some variation in their nutrient content. The protein content in the seeds is similar to that in soybean while the roots have a protein level higher than that of any known tropical root crop. The amino acid composition of the different parts of the winged bean indicates high amounts of lysine and threonine with total essential amino acids similar—or even superior—to that of soybean seeds. All the parts studied except the roots, the unripe pods and the entire plant contain less total S-amino acids than soybean seeds. In terms of their percentage of FAO values adjusted for digestibility, all the different parts show good quality protein which can be utilised in supplementing cereal-based diets.     

Physicochemical and Functional Properties of Winged Bean Flour and Isolate Compared with Soy Isolate

The proximate composition, amino acid profile and functional properties of isolated winged bean proteins were determined and compared with soy protein isolate. Winged bean protein extracted at pH 10 and pH 12 had protein contents of about 90% and 80%, respectively. Alkali extraction of winged bean proteins at pH 10 and pH 12 did not affect the amino acid distribution of the isolated proteins. Oil and water absorption, emulsion, and foaming properties of winged bean isolated compared favorably with soy isolate. Least gelation concentration for winged bean isolate was 18% compared to 14% for soy isolate. Thus, winged bean protein isolate with its high protein content, high lysine and other essential amino acid content and good functionality has a good potential as an ingredient in food products.     

Electrophoretic separation and properties of winged bean seed trypsin inhibitor

Separation of the major trypsin inhibitor protein from crude extracts of winged bean seeds (WBTi) was accomplished using a cathodic polyacrylamide disc gel electrophoretic system. The molecular weight of the WBTi protein was determined to be about 20 000. Winged bean seed extracts showed trypsin-inhibiting (Ti) activity similar to soya bean seed extracts, but large genotypic differences of the Ti activity in winged beans were found. Preliminary studies on the effects of processing on WBTi indicate that aqueous extracts of WBTi are at least as heat-labile as the Ti of aqueous extracts of soya bean seeds. Autoclaving winged bean seed meal prior to protein extraction resulted in considerable reduction of protein solubility.     

Soaking Studies on Winged Bean (Psophocarpus tefragonolobus L.DC) to Process Full-Fat Flour and Determine It's Shelf-Life Stability

Suitable methods to process full-fat flour from dried winged bean seeds, their effect on trypsin-inhibitor activity and keeping qualities of the flour were studied. Soaking in 0.5% or 1% sodium bicarbonate solution and boiling for 30 – 45 min was found to be suitable process for hull removal. Dry dehulling methods resulted in only 14 – 22% hull separation, while wet processing treatments were not effective. Soaking the winged bean seeds (12 hr) in 0.5% sodium bicarbonate, sodium carbonate and sodium chloride solutions reduced 30 – 40% of the trypsin inhibitor activity. Winged bean full-fat flour could be stored for 4 wk under ambient conditions.     

四棱豆油脂、脂肪酸、蛋白质、氨基酸的分析

以4 个四棱豆品种的种子为材料,采用索式提取法、毛细管柱测定总脂肪含量及分析各脂肪酸含量;利用凯氏定氮法、全自动氨基酸分析仪测定蛋白质总量及各蛋白氨基酸组成。结果表明,四棱豆种子中油脂总量在20%～22%,主要含有28 种脂肪酸,油酸占单不饱和脂肪酸的90.7%;多不饱和脂肪酸主要为亚油酸、α - 亚麻酸和EPA;饱和脂肪酸平均含量为25.76%,主要为棕榈酸和硬脂酸。蛋白质总量在38% 左右,必需氨基酸含量丰富。     

Extraction of nitrogenous material from winged bean [Psophocarpus tetragonolobus (L.) DC] flour and the preparation and properties of protein isolates

The extractability of nitrogenous material from the seeds of 12 winged bean accessions has been investigated. Little variation in nitrogen content and extractability in water or salt solution was obtained, although decortication considerably reduced the levels of extraction. The effect of three oil extraction procedures on the extractability of nitrogenous material at different pH values is reported. Protein isolates were prepared and simple laboratory tests were used to evaluate their functional properties. The prepared winged bean isolates possessed very low bulk densities and high fat absorption values and the relationship between these factors was investigated further. Winged bean isolates showed high (100%) nitrogen dispersibilities and were able to form heat-stable emulsions. They did not form gels under the conditions used except in the presence of CaCl₂. Isolates prepared from unheated winged bean flour formed stiff but unstable foams. The relationship between the oil extraction procedure and isolate yield, purity and functional properties is discussed.     

Laboratory Scale Production of Winged Bean Curd

Procedures for the preparation of 100% winged bean or mixed winged bean-soybean curd employing the essential steps of soy curd production have been developed and optimized. Use of magnesium chloride, gluconodelta lactone, acetic acid and calcium sulfate as coagulants was investigated. The results showed that while curd formation was not facilitated by acetic acid, sticky and less cohesive curds could be formed with magnesium chloride and gluconodelta lactone. Calcium sulfate precipitation resulted in a semi-solid and appreciably cohesive curd from winged bean. Winged bean curd had very low hardness value in comparison to soy tofu. Curd products prepared from five ratios of winged bean-soybean mixtures indicate that 50:50 and 25:75 winged bean-soybean combinations by weight resulted in satisfactory products.     

Effect of pH on Formation, Proximate Composition and Rehydration Capacity of Winged Bean and Soybean Protein-Lipid Film

The effect of various pHs on winged bean and soybean protein-lipid films formation, proximate composition and rehydration capacity were studied. Film can only form within a specific range of pH. Films prepared at high pHs (7.5, 9.0, 10.0 and 11.0) contained higher proportions of proteins, ash and carbohydrate but lower proportion of fat than those at pH 6.7, 2.5 and 2.0. Winged bean and soybean films were found to have different pattern of rehydration, however both tended to absorb more water at high pH. With regard to film formation efficiency, nutritional value (higher protein content) and rehydration capacity, soybean film is better than winged bean film.     

四棱豆蛋白质提取工艺研究

以四棱豆为原料,采用碱溶酸析法,通过正交试验,以凯氏定氮法测得四棱豆蛋白质含量和提取率,对碱溶pH值、酸析pH值、提取温度、料液比4个因素进行优化研究,以寻求四棱豆蛋白质提取的最佳提取方法.结果表明,四棱豆蛋白质提取的最优工艺条件为碱溶pH值10.0,酸析pH值4.0,提取温度35 ℃,料液比1:15( m:v).     

Composition of some tropical tuberous foods

Four tropical root tubers were evaluated for their chemical compositions and amino acid patterns. These were winged bean (Psophocarpus tetragonolobus (L.)DC., yam, sweet potato and cassava (Manihot utillisima, Pohl.). Winged bean tubers had protein contents ten times higher than those of cassava and sweet potato and five times higher than yam and contained a high level of carbohydrates. The minerals analysed were about the same in concentration but winged bean tubers had about three times more iron than other root tubers.Although cassava roots have the highest content of S-containing amino acids, winged bean roots have the highest values for lysine, tyrosine, tryptophan and threonine. The total content of essential amino acids is much greater in winged bean tubers than in the other tuberous roots.     

Chemical composition of some less commonly used legumes in Ghana

Three legumes, viz. mung bean, winged bean (seeds, pods and roots) and the yam bean have been analysed with respect to their moisture, protein, fat, soluble carbohydrate, fibre, mineral and energy content. The seeds provide a valuable source of protein, the winged bean having 29%, the mung bean 23% and the yam bean 19%. They are also high in energy content, the winged bean having $\text{400}\text{kcals}\text{100}\text{g}$, the mung bean $\text{310}\text{kcals}\text{100}\text{g}$ and the yam bean $\text{327}\text{kcals}\text{100}\text{g}$. In addition to having the highest protein content, the winged bean seeds provide fair amounts of fat (17·7%) and calcium ($\text{204}\text{mg}\text{100}\text{g}$). The winged bean is significant in that most parts of the plant are edible such as the young leaves, pods and the roots. The roots contain significant amounts of protein and carbohydrate. The production and increased consumption of these legumes has been stressed.     

四棱豆种子及其发酵物挥发性风味成分变化

采用气相色谱- 质谱的分析方法,对四棱豆种子及其发酵物挥发性成分变化进行分析,共鉴定出88 个化合物。结果表明：种子经微生物发酵后成分发生很大变化,同时产生大量新的挥发性成分,发酵前后只有苯乙醛、3,3,5- 三甲基环己酮两种完全相同的物质;在种子挥发性成分中含量较高的是醇类、酮类、烯烃类;种子发酵物主要挥发性成分是酯类、醚类、烯烃类。     

Volatiles derived from lipoxygenase-catalysed reactions in winged beans (Psophocarpus tetragonolobus)

Volatiles formed by the decomposition of hydroperoxides generated by lipoxygenase-catalysed oxidation of linoleic acid contribute a beany flavour to legumes. Eleven volatiles have been identified after treatment of linoleic acid by lipoxygenase extracted from winged bean seeds. Five of these volatiles; namely, hexanal, 2-heptanone, 2-pentyl furan, undecane and tridecane, have been detected in the headspace of a sample of winged bean flour after storage. Moisture levels below 10% appear to inhibit lipoxygenase activity, since headspace samples from raw and heat treated samples had very similar composition, and the peroxide value remained low after 10 months' storage at 37°C. Incubation of a lipoxygenase extract with linoleic acid gave rise to a larger concentration of volatiles at pH 9 than at pH 6·5 due to the increased lipoxygenase activity at the higher pH.     

Variation in protein and trypsin inhibitor activity with maturity and amino acid composition of winged bean (Psophocarpus tetragonolobus) seeds

The protein and trypsin inhibitor activity in pods and seeds of winged bean (Psophocarpus tetragonolobus (L) DC) increase, and in the pod hull decrease, with the maturity of plant. The seeds of 21 cultivars both exotic and of Indian origin cultivated on marginal alkaline soil (pH 8.7) were analysed for protein (36.4–45.3) and amino acid composition (lysine 4.8 to 6.7).     

The protein,trypsin inhibitor and lipid of the winged bean [Psophocarpus tetragonolobus (L) DC] seeds

The protein, trypsin inhibitor and lipid of the seeds from 15 New Guinea and 15 Thai winged bean varieties grown in Malaysia were analysed. The results show that winged bean seeds have a high protein content, ranging from 27.8 to 47.2% (based on dry seed wt). The trypsin inhibitor contents vary from 1.6 to 3.6 million i.u. 100 g^?1 of seeds; these trypsin inhibitor activities could be destroyed almost completely by a simple heat treatment. The oil content varies from 15.2 to 27.8% of the dry seed wt. Saturated fatty acids account for 31–37% of the total fatty acids and behenic acid (22:0) alone constitutes about 14–17% of the saturated fatty acid content. Unsaturated fatty acids account for 63–69% of total fatty acids; oleic and linoleic acids together constitute 57–64% of the unsaturated fatty acids.     

Nutritional composition, processing, and utilization of horse gram and moth bean

Horse gram and moth bean are the unexploited legumes of the tropics and subtropics grown mostly under dry-land agriculture. The chemical composition is comparable with commonly cultivated legumes. Like other legumes, these are deficient in methionine and tryptophan. Horse gram is an excellent source of iron and molybdenum. Comparatively, horse gram seeds have higher trypsin inhibitor and hemagglutinin activities and polyphenols than moth bean seeds. Dehusking, germination, cooking, and roasting have been shown to produce beneficial effects on nutritional quality of both the legumes. Both the legumes require prolonged cooking to obtain product of acceptable nature. A soak solution (1.5% NaHCO3 + 0.5% Na2CO3 + 0.75% citric acid) treatment has been shown to reduce cooking time and improve protein quality. Moth bean is mostly consumed as dhal or sprouts. The whole seeds of horse gram are generally utilized as cattle feed. However, it is consumed as a whole seed, sprouts, or whole meal by a large population in rural areas of southern India. Medical uses of these legumes have been discussed.     

Some characteristics of the roots of the winged bean [Psophocarpus tetragonolobus (L.) DC]

Three accessions of winged bean [Psophocarpus tetragonolobus (L.) DC] tuberous roots from Thailand were examined for their crude protein (N × 6.25), non-protein nitrogen and starch contents. The roots were further analysed for their trypsin inhibitor and urease activities and for the presence of tannins and cyanogenic compounds. Crude protein was found to be high in comparison with other root crops (5.7–6.7% fresh weight) and this contained a high proportion of non-protein nitrogen (7.4–15.0%). Amino acid content of the crude protein, when compared with mature winged bean seeds, revealed a deficiency in the sulphur-containing amino acids but an exceptionally high aspartic acid content. Starch was the major carbohydrate present in the flesh of the roots (21.7–32.1% fresh weight). Root samples were found to contain high levels of trypsin inhibitory activity (13.5–30.1 TIU mg^?1 fresh weight). No urease activity or cyanide could be detected in any of the root accessions studied.     

THERMODYNAMICS OF MOISTURE SORPTION IN WINGED BEAN SEED AND GARI

Experimental data on sorption isotherms of gari and winged bean seeds were used to determine their thermodynamic functions (heat of vaporization, spreading pressure, net integral enthalpy and entropy). The heat of vaporization of both products reduced with increase in moisture content and approached that of saturated water at moisture contents of about 15%. Within the moisture content range of 2.0 and 18.0%, the net integral enthalpy and net integral entropy of gari were respectively higher and lower than those of winged bean seeds. The maximum net integral enthalpy for gari was 556 kJ/kg and was 335 kJ/kg for winged bean seeds. The difference in the values of the thermodynamic functions were attributed to the higher amount of oil/fat in winged bean seeds and the presence of gelatinized starch in gari.     

四棱豆硒蛋白与其它硒源的生物利用研究

以雌性SD大鼠为研究对象建立低硒的动物模型,通过灌胃的形式给大鼠分别补充不同剂量的亚硒酸钠、富硒酵母和四棱豆硒蛋白。检测大鼠血清和肝肾中的硒含量、谷胱甘肽过氧化氢酶(GSH-px)、超氧化物歧化酶(SOD)、硫氧还蛋白还原酶(TrxR)的活性和丙二醛(MDA)的含量来比较其生物利用的效果。结果表明:与低硒对照组相比,所有加硒处理组的大鼠血、肝、肾中的硒含量以及所含的硒酶活性均明显提高(P<0.05),在同一补硒水平上,亚硒酸钠组的肝肾硒含量低于富硒酵母组和四棱豆硒蛋白组(P<0.05);亚硒酸钠组的血清和肝肾的谷胱甘肽过氧化氢酶(GSH-px)、超氧化物歧化酶(SOD)、硫氧还蛋白还原酶(TrxR)的活性和丙二醛(MDA)的含量都低于富硒酵母组和四棱豆硒蛋白组(P<0.05)。结论:四棱豆硒蛋白和富硒酵母增加大鼠的硒含量高于亚硒酸钠组(P<0.05),其它硒酶的影响是四棱豆硒蛋白最优,硒蛋白能更好地被低硒大鼠吸收利用。     

Carbohydrate Composition of Winged Bean (Psophocarpus tetragonolobus)

The carbohydrate composition of winged bean has been studied. The seeds contain about 42.2% total carbohydrates of which starch alone accounts for 36.2%. The total monosaccharides constituted 2.7% and were identified as glucose (1.17%) and fructose (1.5%); oligosaccharides amounted to only 0.61% and were identified as sucrose, raffinose, stachyose, and verbascose, on a dry defatted basis. The cold water soluble gum of winged bean contains glucose and xylose as the major sugars together with a small amount of arabinose while hot water soluble gum was found to be a glucantype polymer. Hemicellulose A consisted of glucose, xylose, and arabinose (15.5:9:1) whereas hemicellulose B consisted exclusively of glucose indicating that it is also a glucan-type polymer.