Hypocholesterolemic Properties of Protein Isolate from Cowpeas (Vigna Unguiculata) Sprout in Normal and Diabetic Rats

This research was aimed to determine the potency of hypocholestrolemic properties of protein isolate from cowpeas sprout through in vivo bioassay by using Sprague Dawley male rats. The treatments of the research were rat conditions (normal and diabeic rats) and feed treatments (standard and protein isolate feed). Blood triglyceride, cholesterol total, High Density Lipoprotein (HDL), and Low Density Lipoprotein (LDL), of rats were analysed on 3^th, 6 ^th, 9 ^th, 12 ^th, 15 ^th days for the treatment and before treatment as control. The result of this research showed that the blood triglyceride, cholesterol total, LDL decreased and the blood HDL increased in diabetics rats with protein isolate treatment. The potency of hypocholestrolemic activity were shown by the ratio of cholesterol total/HDL and LDL/HDL. The ratio of the rats were normal, exception diabetic rats with standart feed.     

Oligosaccharide Content of 20 Varieties of Cowpeas in Nigeria

Mature dry seeds of 20 varieties of cowpeas (Vigna unguiculata) grown in Nigeria were analyzed for their sucrose, raffinose and stachyose content. The dry seeds were ground into powder, extracted with 80% ethanolandthe extract analyzed by paper chromatography using a mixture of n-butanol, ethanol, water and ammonia solution 8:1:2:1 v/v). The results show a progressive decrease in raffinose and stachyose content with dehulling and cooking and an increase in sucrose level after cooking. The average content of the sugars in whole beans on dry weight basis was sucrose 0.8%, raffinose 2.6% and stachyose 3.3%. The average content for dehulled raw beans were sucrose 0.7%, raffinose 1.8% and stachyose 2.4% while in cooked beans it was 1.6%, 1.3%, and 1.8%, respectively.     

Reversibility of the Hard-to-Cook Defect in Dry Beans (Phaseolus vulgaris) and Cowpeas (Vigna unguiculata)

The hard-to-cook defect, assumed to be a permanent condition in legume seeds, can be reversed. Dry beans (Phaseolus vulgaris) and cowpeas (Vigna unguiculata) which had developed the hard-to-cook defect when stored at 29°C, 65% RH had progressively shorter cooking times after additional storage at 6.5°C, 71% RH. This would suggest that the mechanism(s) leading to development of the defect should be easily reversed. The ability to reverse the hard-to-cook defect in legume seeds would provide several economic and nutritional benefits.     

Gelatinisation of Starch in Cowpeas (Vigna unguiculata)

The course of gelatinisation was followed during the cooking of cowpeas. Dry cowpeas were only gelatinised to the extent of 60% after 5 h cooking but pre-soaking in tap water enabled gelatinisation to be completed in this time. Soaking in polyphosphate solutions and a “kawe” solution resulted in similar marked improvement in gelatinisation rate.     

糙米发芽过程中内源酶活力及主要成分的变化

目的：探讨糙米在发芽过程中内源酶活力和主要成分的变化规律及相关性。方法：以“早944”稻米为材料制备发芽糙米,在30℃下发芽培养72h,每隔12h对其内源酶活力和主要成分含量进行测定。结果：糙米内α-淀粉酶、β-淀粉酶、蛋白酶、谷氨酸脱羧酶、植酸酶等内源酶活力呈现上升趋势,发芽72h时酶活力分别达5.45U/g、3.78U/g、14.08U/g、9.72U/100g、3.44U/g;γ-氨基丁酸、还原糖、游离氨基酸含量呈现增长趋势,发芽72h时含量分别为237.05mg/100g、18.15mg/g、214.94μg/g;同时,总糖、粗蛋白和植酸含量呈现降低趋势,发芽72h时含量分别为44.16、9.59、1.99mg/g。结论：内源酶与其代谢的底物及代谢产物之间都存在显著相关性,部分内源酶与非内源酶代谢相关底物及产物之间亦存在显著相关性。糙米发芽72h后的营养价值高于发芽前,适宜用作新型糙米食品的生产原料。     

Acceptability and Nutrient Content of Milk Substitutes from Four Cultivars of Cowpeas (Vigna unguiculata)

Milk was extracted from four cultivars of cowpeas and analysed for their nutrient content. The protein content of the milk substitutes varied from 1.2-3.0g, energy, 17.9-42.4 Kcal; total solids 4.2-10.7g and sugars from 0.2-0.6g per 100 mL. The protein digestibility was from 56.0-78.5% and trypsin inhibitor activity was 5.8-7.1 TIU/mL. The cultivars had an effect on the yields, the total solids, the energy, protein total sugars, trypsin inhibitor activity, and digestibility of the milk substitutes.     

Effect of Processing on Certain Antinutrients in Cowpeas (Vigna unguiculata)

Four Nigerian cultivars of cowpeas were analyzed for raffinose, stachyose, phytic acid, tannins, and trypsin inhibitory activity after dehulling, cold-soaking, hot-soaking, and cooking as ewa-ibeji and moin-moin (two popular Nigerian cowpea foods). Dehulling decreased stachyose and removed the tannins. Hot-soaking caused a significant reduction in stachyose and trypsin inhibitory activity. Ewa-ibeji and moin-moin contained similar quantities of antinutrients, except for tannins which were absent in moin-moin.     

Effect of Dry Heat Pre-Treatment (Toasting) on the Cooking Time of Cowpeas (Vigna unguiculata L. Walp)

Four cowpea varieties (Brown beans, Oloka beans, IAR48 and IT89KD-288) were toasted at 105 °C, and used to study the effect of dry heat treatment on the cooking time and nutrient composition of cowpea seeds and also its effect on the functional properties of resultant flour of the cowpea seed varieties. Toasting reduced the cooking time for brown and oloka cowpea varieties from 55.00–31.00 and 70.67–51.67 min, respectively. The cooking time for IAR48 and IT89KD-288 cowpea varieties increased from 104.67 to 106.00 and 88.00 to 88.67 min, respectively. The results indicate that the cooking time of cowpea seeds can be reduced significantly on toasting, while maintaining their potential as functional agents in the food industry for nutrition and utilisation. Correlation between the amount of water imbibed by cowpea seeds and their cooking time was -0.74, but was not significant at p ≤ 0.05, suggesting that there is no significant relationship between the amount of water imbibed by cowpea seeds and their cooking time.     

Protein and Starch Digestibility and Flatulence Potential of Germinated Cowpeas (Vigna unguiculata)

In vivo and in vitro methods with experimental rats and commercial digestive enzymes, respectively, were used in assessing the protein and starch digestibility and flatulence potential of germinated cow-peas. Germination (24 hr at 25° or 30°C) reduced the flatulence potential of seeds (52 to 77%). In vivo digestibility of starch and protein was also significantly increase by germination. Germination did not affect in vitro protein digestibility, but reduced in vitro digestibility of freeze-dried and 70°C-dried starch. Cooking in boiling water significantly increased in vitro protein and starch digestibility of both ungerminated and germinated seed.     

藜麦发芽过程中蛋白质与皂苷及淀粉消化特性的变化规律

发芽是改善谷物质构及其营养价值的一种高效的加工方式。本文研究了藜麦发芽过程中蛋白质与皂苷及淀粉消化特性的变化规律。结果显示,发芽显著地提高了藜麦中粗蛋白和可溶性蛋白含量,分别增加了5.38%和17.55%。随着发芽时间不断增加,藜麦总淀粉、直链淀粉及支链淀粉含量分别减少25.95%、4.86%和29.53%,而还原糖含量增加了26.60%。发芽处理显著改善了藜麦种子的淀粉消化性能。发芽前藜麦种子中快消化淀粉、慢消化淀粉及抗性淀粉的百分含量分别为38.45%、43.64%和17.90%。发芽48h后,快消化淀粉的百分含量显著地增加至53.46%,而慢消化淀粉及抗性淀粉的百分含量分别下降至40.42%和6.11%。此外,发芽后藜麦种子中总皂苷含量显著增加了16.46%。研究表明,发芽的藜麦种子含有更好的营养价值和消化性能,可以用于加工功能性食品,促进人体健康。     

Effect of Soaking and Cooking on the Oligosaccharide Content of Dry Beans (Phaseolus vulgaris, L.)

The effect of cooking conditions commonly used in Brazilian homes was determined by measuring the oligosaccharide content (sucrose, raffinose and stachyose) of beans (Phaseolus vulgaris, L.) by thin-layer chromatography. Soaking in water caused a small decrease in the oligosaccharide content of the beans and the relative amount removed was not proportional to the solubility of the sugars in water. Cooking of the whole seeds led to a larger decrease in oligosaccharide content, especially when large amounts of water were used.     

不同氧分压贮藏条件下金针菇衰老相关酶活性的研究

研究不同氧分压条件下金针菇贮藏过程中抗氧化相关酶活性的变化及其对保鲜效果的影响。在聚乙烯塑料袋中放入金针菇100g、膨润土吸湿剂8g、活性炭6g,分别按0、20%、50%、70%、80%、90%、100%氧气分压充气包装,于1～3℃冷藏,每隔5～7d取样检测。结果显示：80%氧气分压试验组的保鲜效果最好;在贮藏的最初2周,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、脂氧合酶(LOX)等与抗氧化、清除自由基相关的酶活性明显升高,多酚氧化酶(PPO)、过氧化物酶(POD)、纤维素酶(CMCase)等酶活性降低;贮藏2周后SOD、CAT、LOX等酶活性明显减弱,POD、PPO等酶活力明显增强。表明SOD、CAT、LOX等抗氧化酶活性的减弱,导致菇体内O2－ ·、 ·OH、过氧化物等逐渐积累,细胞膜结构受损,细胞内容物外渗增多;纤维素酶对细胞壁降解,导致组织软化出水,酶促褐变活力增强,是致使金针菇衰老、加速变质、品质降低的重要原因。     

苦荞发芽期不同部位的活性成分含量变化

苦荞发芽后,将其分为芽及去除芽后的籽粒两部分,在发芽期间,对芽和籽粒中的总黄酮、芦丁、槲皮素及D-CI含量变化进行研究。发芽第二天开始,随着发芽时间延长,芽粉中总黄酮、芦丁、D-CI含量呈下降趋势,槲皮素含量缓慢上升;发芽第二天,芽粉中D-CI含量高达18.38 mg/g,未萌动的苦荞全粉中D-CI含量为0.32 mg/g。随发芽时间延长,全粉中总黄酮、芦丁含量呈先上升后下降趋势,在发芽萌动第七天总黄酮含量达到最大值,为27.92 mg/g,第六天芦丁含量达到最大,为23.13 mg/g;槲皮素含量变化呈上升趋势,在发芽中后期含量上升迅速,发芽第八天其含量为6.85 mg/g;D-CI含量变化呈缓慢上升趋势,第一天其含量为1.07 mg/g,第六天其含量为1.51 mg/g。芽粉中总黄酮、芦丁、D-CI在发芽初期含量较高;全粉中D-CI的合成也主要发生在发芽初期,芦丁、槲皮素的合成主要在发芽中后期。     

马铃薯发芽过程中不同块茎部位自由基代谢相关酶活性及抗坏血酸含量的变化

试验以海花1号为试材,对马铃薯不同部位发芽过程中SOD、CAT、PPO、POD活性、POD同工酶谱和抗坏血酸含量进行了分析.结果表明,马铃薯发芽过程中,SOD活性,芽体中最高,其次为芽周,薯肉中最低.芽体和芽周PPO活性,随萌芽进程而逐渐升高;薯肉中PPO活性小芽期降低,到大芽期又迅速升高;小芽期,芽体PPO活性最高,芽周和芽体中依次降低;大芽期,薯肉中PPO活性最高,而芽周和芽体中相对较低.薯肉和芽周POD活性均较低,而芽体POD活性较高.所有POD同工酶谱带均集中在阴极区域,不同时期、不同部位都有A带和B带;薯肉和芽周中只有A带和B带,且谱带轻淡;芽体中的A带和B带浓密,且随着萌芽进程发展,又新增C带、D带、E带、F带和G带五条分子量较小的同工酶谱带.CAT活性在不同时期、不同部位变化不大.抗坏血酸含量在萌芽过程中呈增加趋势.     

Changes in enzyme activities during germination of cowpeas (Vigna unguiculata,cv. California blackeye)

Cowpeas (Vigna unguiculata, cv. California blackeye), steeped at 25°C for 20 min, were germinated at room temperature for 0, 1, 2 and 3 days. The samples were then dried at 60°C for either 2.5, 5, 7.5 or 10 h. α-Amylase, β-amylase and endo-(1,3)(1,4)-β-D-glucanase activities were determined in the cowpea samples. The results obtained showed β-amylase activity was not present in any of the experimental samples. Germination had a highly significantly positive effect on α-amylase activity (P<0.05), where activities ranged from 85.6 to 720.9 μmoles maltose/ml/min at day 0 to day 3 of germination. The effect of germination and drying time on α-amylase activity was significant (P<0.05). Compared to α-amylase activity, the activity of endo-(1,3)(1,4)-β-D-glucanase was low. Further analysis, using Duncan's Multiple Range Test, indicated that there was no significant difference in α-amylase activity in samples dried for 5–10 h at 60°C.     

萌发大麦种子内肽酶活力、醇溶蛋白及氨基酸含量变化

以两个大麦品种垦啤8号和Harrington为材料研究了大麦种子萌发过程中体内醇溶性蛋白质、游离氨基酸和内肽酶活力的变化。垦啤8号大麦种子的醇溶蛋白含量高,但其降解量比Harrington多。垦啤8号游离氨基酸增长量略高于Harrington。整个大麦种子发芽期间,国产品种内肽酶活力始终高于进口品种。以上表明,与Harrington相比,虽然国产品种垦啤8号含氮量高,但其内肽酶活力升高快,最大酶活力高,醇溶蛋白降解、转化为可输出氮的进程快,有制造优质麦芽的潜力。     

燕麦发芽过程中多酚含量及其抗氧化活性的变化

以山西产裸燕麦为原料,在控制的条件下发芽72h,每间隔12h取样,研究燕麦发芽过程中多酚含量及其抗氧化活性的变化。试验结果表明:发芽时间对燕麦多酚含量及抗氧化活性有很大的影响。与原粮相比,燕麦发芽过程中游离酚、结合酚及总酚含量均有不同程度的增加;燕麦多酚提取物清除ABTS自由基的能力随着发芽的进行而显著增强;发芽过程中燕麦游离酚和结合酚提取物对质粒DNA损伤的保护作用均优于原粮,但清除羟基自由基能力均低于原粮或与原粮相当。     

不同发芽时间下发芽稻谷和糙米不同部位γ-氨基丁酸含量差异

选用云南和浙江近期育成的γ - 氨基丁酸(GABA)含量差异较大的水稻品种(系)26 个,在云南新平相同栽培条件下种植,比较研究其稻谷和糙米不同发芽时间对不同部位GABA 含量累积的差异。结果表明：供试26 个品种(系)以滇农S-1/ 滇靖8 号、HIPj1、文稻1 号/IR36、和文稻2 号/IR36 四个品种(系)GABA 含量最高;萌发前GABA 含量各部位依次为皮胚＞颖壳＞糙米＞精米。萌发活化24～28h 能显著促进萌发稻谷和糙米中GABA 含量的累积,呈现先升高后降低的变化趋势,尤其是糙米在萌发后24h 达到最高峰值。稻谷和糙米萌发后不同的部位GABA 的累积速率和累积量不同,各部位GABA 含量依次为：胚芽＞糙米＞精米,颖壳最低;萌发活化后GABA含量累积呈现糙米大于稻谷;胚芽中GABA 含量粳稻高于籼稻。     

花生种子萌发过程中蛋白酶、脂肪酶及SOD、CAT酶活性变化

以鲁花11号为试验材料研究了花生种子不同萌芽时期,予叶、胚轴、真叶三部位的可溶性蛋白质含量及脂肪酶、CAT、SOD活性.结果表明,花生种子萌发过程中,子叶中的可溶性蛋白质含量在萌发前期较稳定地保持较高水平,第7期陡然升高,但随后又直线下降;下胚轴和真叶中的可溶性蛋白质含量都比较低,各时期之间的绝对变动幅度不大.蛋白酶活性,子叶最低,胚轴居中,真叶最高;子叶蛋白酶活性变化较平缓;胚轴中初期较高,第4期以后基本处于相对稳定状态;随真叶的不断长大,蛋白酶活性逐渐下降.胚轴中的SOD活性相对稳定;真叶和子叶SOD活性变化活跃,出现高-低-高-低波动变化;但总体上各部位、各时期保持较高的SOD活性.胚轴中CAT活性初期较高,中后期低而相对稳定;子叶和真叶CAT活性总体上相对稳定,并保持较高活性.脂肪酶活性子叶保持较高活性,而真叶和胚轴活性较低.