Chemical evaluation of multimixes formulated from some local staples for use as complementary foods in Nigeria

The nutrient composition of eight multimixesformulated for use as complementary foods fromprocessed soybeans, cowpeas, maize, sorghum, yams,cocoyams, plantains and sweet potatoes were examined. The foods were processed by sprouting, cooking andfermentation. The samples were separately dried andmilled to fine flours. A ratio of 65% cereal, 30%legume and 5% starchy staple (65:30:5) calculated ona protein basis was used to formulate the multimixes. The blends were chemically analyzed using standardprocedures. The mixtures containing soybeans hadhigher protein, lipid, energy, crude fiber and calciumlevels but lower carbohydrate content than thosemixtures without soybean. The protein and energylevels of the multimixes were higher than those ofsome commercial infant foods (Cerelac, Farex andNestrum) in Nigeria but were comparable to that of`soy-ogi'. The multimixes contained fair quantitiesof calcium and phosphorus and an adequate amount ofsome of the essential amino acids. Methionine was themost limiting amino acid in all the mixtures. Blending cowpeas with maize produced a higher proteinscore than blending cowpeas or soybeans with sorghum. The cowpea/maize/sweet potato mixture had the highestprotein score.     

盐胁迫对大豆发育子叶愈伤组织的生化影响

在含不同浓度ＮａＣｌ的ＭＳ培养基上，继代５次培养大豆发育子叶的愈伤组织，分析了不同盐浓度培养的大豆愈僵组织的蛋白质，氨基酸和可溶性糖的含量。经测定表明，盐胁迫下，大豆愈伤组织的蛋白质，总氨基酸含量都比对照高，可溶性糖含量比对照低。ＮａＣｌ浓度在０－０．１％范围内，随ＮａＣｌ浓度的增加，蛋白质与总氨基酸的含量逐渐增加，当ＮａＣｌ浓度增至０．１５％时，蛋白质和总氨基酸含量又降低。     

诸葛菜的营养成分分析

宏量营养物、氨基酸、维生素和微量元素的分析结果表明，诸葛荣富含蛋白质、人体必需氨基酸、矿物元素和维生素，是营养优良的食物源。     

Protein quality of some Nigerian traditional diets based on the African yambean (Sphenostylis stenocarpa) and pigeon pea (Cajanus cajan)

The protein quality of Nigerian traditional diets based on the African yambean (AYB) and pigeon pea (PP) were performed by in vivo and in vitro bioassays. The individual foods were processed, cooked, dried and mixed to resemble the traditional diets. Weanling male Wistar rats (45–55 g) were used for the bioassay. The rats were fed ad libitum for 35 days of which 28 days were for growth and 7 days for N-balance. All the eleven diets including casein (control) provided 1.6 g N/100 g diet. The parameters tested include PER, growth, N-balance, BV, NPU and apparent digestibility (AD). The rats fed the AYB diets, except AYB: Agidi (Ag), showed superiority in most of the parameters tested. There were significant positive correlations between PER and NPU (r=0.925;p<0.001); PER and AD (r=0.908;p<0.001); PER and body weight gain (r=0.969;p<0.001). The in vitro protein digestibility of the diets was significantly correlated (r=0.80;p<0.01) with the in vivo apparent digestibility. These parameters were used to rank the various diets. Crayfish protein was a better supplement to legume/cereal or legume starchy staple mixtures than leguminous oil seed. However, supplementation of PP: steamed corn (SC) diet with crayfish did not prove beneficial. The result showed that diets based on the African yambean, an under-exploited legume, are nutritious. The need for its reintroduction into the fare of the populace through increased production and appropriate processing technology is stressed. The results of this study can form a base for the standardization of Nigerian diets based on these legumes.     

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.     

不同生态条件下氮磷钾配施对强筋小麦陕253品质的影响

以优质强筋小麦品种陕253为材料．在不同生态条件下．研究了不同N、P、K配置施肥对籽粒蛋白质含量、吸水率、硬度、容重、湿面筋、沉淀值、出粉率、稳定时间和降落值9个主要品质指标的影响。结果表明，在不同N、P、K肥配置处理后籽粒蛋白质含量、吸水率、硬度、容重、湿面筋、沉淀值和出粉率变化不大，但不同生态环境条件对其影响明显，降落值受N、P、K配置和生态环境条件共同影响，稳定时间对N、P、K肥料配置反应比较敏感，以每公顷施N135kg、P2O5 225kg和K2O 120kg处理的稳定时间最长，达24．6min。     

Effects of Soybean Fortification on Protein Quality of Tortilla-Based Diets Produced from Regular and Quality Protein Maize

The physiological development of laboratory rats fed with a typical indigenous tortilla diet was studied for two generations. The experiment compared casein control diet and five different types of diets: (1) a diet of tortillas obtained from fresh masa (FM); (2) regular tortillas produced from enriched dry masa flour containing vitamins B₁, B₂, niacin, folic acid, and the microminerals iron and zinc (REDMF); (3) tortillas produced from enriched dry masa flour fortified with 6% defatted soybean meal (FEDMF); (4) tortillas produced from enriched quality protein maize flour (EQPM); and (5) and, tortillas produced from enriched quality protein maize flour fortified with 3% defatted soybean meal (FEQPM). The growth of rats fed FEDMF and FEQPM diets was significantly higher (P<0.05) in both generations than their counterparts fed EQPM, REDMF, or FM diet. Animals fed quality protein maize (QPM) tortilla had the highest protein digestibility, but the FEQPM and FEDMF diets had the highest biological value (BV), net protein utilization (NPU), and protein-digestibility-corrected EAA scores (PDCEAAS). The difference among treatments was more evident in the second-generation rats. The pregnancy rate, number of newborns/litter, litter weight, and newborn survival rate was also higher for rats fed FEDMF, EQPM, and FEQPM diets than their counterparts fed REDMF and FM.     

Nutritive characterization of purslane accessions as influenced by planting date

The uniqueness of purslane (Portulaca spp.) asthe richest vegetable source of omega-3 (-3)fatty acids is well documented. However, purslane hasnot been domesticated or fully evaluated for itsnutritive value. The objective of this study was todetermine the influence of planting date on chemicalcomposition of purslane accessions. Eight accessionsfrom different geographical locations were planted 12days apart, and whole plants harvested at full bloom. Chemical analysis (DM basis) of leaves showedsignificant differences among varieties for all thecharacteristics measured. Accession by planting dateinteraction influenced (p < 0.05) levels of crudeprotein, total lipids, and carbohydrate contents. Wild Greek accession had the highest, while aBeltsville (Maryland) wild type had the lowest crudeprotein content (27.1 vs 20.5%) at the secondplanting date. Crude protein, lipid and ash levelswere most influenced (p < 0.05) by planting date. Total lipids varied from 4.0–5.8% and 3.7–5.1% forthe first and second planting dates, respectively. Selected fatty acid content indicated significantly(p < 0.05) higher levels of 18: 26, and18: 33 in the Dutch Garden accession comparedwith other varieties. The Egyptian wild accession hadthe lowest level of 18: 33. The ratio of 3 to 6 acids, which ranged from 5.5 to22.3 indicated a highnutritive value of purslane compared to other oilcrops such as soybeans and perrilla. The high levelsof protein in purslane compete with those of othercommercially important vegetable crops. The studyshows that, in spite of its genetic diversity, purslaneremains one of the most abundant terrestrial vegetablesources of Omega-3 fatty acids and other essentialnutrients potentially beneficial for humans as well asanimals.     

苏云金芽胞杆菌WB5中营养期杀虫蛋白3Aa基因(vip3Aa)的克隆、表达与纯化

营养期杀虫蛋白(vegetative insectcidal protein,Vip)是由苏云金芽胞杆菌(Bacillus thuringiensis,Bt)在营养生长指数中期至稳定期期间分泌产生的一类新型杀虫因子,分为Vip1、Vip2和Vip3三种,以Vip3的研究最为深入。Vip3A对鳞翅目(Lepidoptera)害虫具有广谱杀虫活性,具有重要研究意义。本研究以Bt WB5菌株总DNA为模板,采用PCR方法扩增vip3Aa(Gen Bank登录号:AAM22456)全长,将该片段纯化回收后与p MD18-T连接并转入大肠杆菌(Escherichia coli)DH5α,进行酶切验证和序列测定。将vip3Aa基因片段与经同样酶切的表达载体p Czn1连接,构建重组表达载体p Czn1-vip3Aa,转入大肠杆菌Arctic ExpressTM(DE3),异丙基-β-D-硫代吡喃半乳糖苷(isopropylβ-D-1-thiogalactopyranoside,IPTG)进行诱导表达。SDS-PAGE结果表明,在沉淀和上清中均有约88 k D VIP3Aa蛋白质表达产物;采用Ni亲和树脂对上清中的VIP3Aa融合表达蛋白进行了纯化,获得了纯化蛋白。本研究成功亚克隆了vip3Aa基因,并表达纯化了VIP3Aa蛋白,为后续研究VIP3Aa蛋白在昆虫中肠的作用受体提供了基础资料。     

基因工程及花色素合成途径在花色改良中的研究进展

随着经济的发展,转基因技术在花卉中的应用也越来越关键,通过基因工程使花色发生变化已经在商业中运用。生物碱类、胡萝卜素和类黄酮化合物等一类活性物质共同作用使植物的花色更具观赏性,目前,在花色改良上应用较多的是类黄酮色素,其研究机理也较为清楚。本文主要介绍了F3＇5＇H（类黄酮-3＇,5＇-羟基化酶）和F3＇H（类黄酮-3＇-羟基化酶）的生物合成途径,阐述了基因工程技术对花色修改的作用,综述了目前花卉转基因工程的研究现状和花色素合成的主要途径及影响因素,同时简单介绍了目前改良花色的几种策略和就其存在的问题、发展前景做出了讨论。