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醇法大豆浓缩蛋白酶法改性研究 总被引:9,自引:0,他引:9
为提高醇法大豆浓缩蛋白的溶解性,采用Alcalase蛋白酶对醇法大豆浓缩蛋白进行酶法改性试验。试验表明,酶法水解能显著提高大豆浓缩蛋白的溶解性。酶解的最佳条件是pH8.5、温度62℃、底物浓度5%,酶浓度2%(E/S),在此条件下酶解4h,大豆浓缩蛋白的水解度在12%以上,大豆浓缩蛋白的NSI从10%提高到85%左右,有较好的溶解性。并利用浊度法测定了不同水解度条件下酶解大豆浓缩蛋白的乳化特性,结果表明水解度约为8%时乳化性最大,水解度约为6%时乳化稳定性最好。 相似文献
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利用中性蛋白酶、木瓜蛋白酶对麦胚蛋白的溶解特性进行改善。系统研究了底物浓度、酶浓度、酶解时间、pH、温度等工艺条件对麦胚蛋白酶解物的溶解特性的影响。试验结果表明:中性蛋白酶的水解度以及水解产物的溶解度优于木瓜蛋白酶。在底物浓度10%,中性蛋白酶浓度1.0%,酶解时间2.5h,pH6.5,温度35℃条件下麦胚蛋白水解度1.40%,溶解度58.7%,比酶解前溶解度24.3%有较大提高。 相似文献
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功能性乳清多肽的研制 总被引:8,自引:0,他引:8
研究了碱性蛋白酶和胰蛋白酶对乳清蛋白的水解作用,通过正交试验,得出各自的最优水解条件,结果表明,碱性蛋白酶较适合底物乳清蛋白,水解乳清蛋白的最优组合为:[E/S]=5%、T=60℃,PH=8.0,水解度=21.6%,多肽水解液在等电点附近溶解度为90%,经灭菌处理后溶解度高达94%以上。 相似文献
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木瓜蛋白酶水解大豆分离蛋白的研究 总被引:5,自引:0,他引:5
大豆分离蛋白经过加热预处理,木瓜蛋白酶2hr酶解后,水解度比不处理提高1倍,最佳处理条件为:90℃,10min,水解度的变化和大豆分离蛋白的SH含量变化有关。通过极差分析木瓜蛋白酶水解大豆分离蛋白正交实验,结果表明最佳水解条件为:PH=7.0,E:S=2.0%,温度55℃,反应时间12hr。 相似文献
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以猪血红蛋白为原料,研究蛋白酶水解制备抗氧化肽的工艺.通过研究酶解时间、酶与底物比、酶种类对制备的抗氧化肽还原力和水解度影响,筛选出最佳蛋白酶及制备抗氧化肽的最佳工艺条件.结果表明:7种酶中,胃蛋白酶的水解度和还原力最佳.胰蛋白酶和胃蛋白酶复合水解比单酶水解的水解度提高了11.83%,还原力没有显著性差异.在此基础上设计单酶响应面,得到最佳还原力酶解条件为:酶解温度37.31℃、pH1.95、酶与底物比3526.74U/g.脱色条件为活性炭用量3%、pH4.0、温度70℃、脱色时间1h,粉末状活性炭的脱色率达到85.69%,蛋白质损失率20.32%. 相似文献
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碱性蛋白酶酶解大豆分离蛋白可以制备大豆多肽,用茚三酮比色法测定酶解液中氨基氮的含量来判断其酶解效率.影响大豆分离蛋白酶解的主要因素有酶用量、酶解pH值、底物浓度、酶解温度、酶解时间等,通过单因素和优化酶解条件正交试验分析,筛选出碱性蛋白酶酶解的最适试验条件是:在酶用量为7%,pH值为8.5,温度50℃,底物与溶剂的固液比为1∶15,酶解时间5h效果较好. 相似文献
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以大豆分离蛋白为原料,选用Alcalase 2.4L碱性内切酶和Flavourzyme风味蛋白酶对大豆分离蛋白进行酶法水解及脱苦工艺研究。以水解度和苦味分值为考察值,对酶解工艺进行优化,确定最佳条件。结果表明:Alcalase2.4L碱性内切酶最佳酶解条件为加酶量14 000 U/g、酶解温度60℃、酶解pH8.5、底物质量分数5%,酶解时间2h,最终水解度为45.34%,此时水解液苦味值为4。Flavourzyme风味蛋白酶对水解液进行二次水解的最优酶解条件为加酶量300 U/g、酶解温度55℃、酶解pH 7.0、酶解时间3 h,此条件下大豆分离蛋白水解液苦味值最低为1.2。Alcalase2.4L碱性内切酶和Flavourzyme风味蛋白酶水解大豆分离蛋白使水解度得到较大提高的同时也解决了水解液的苦味问题。 相似文献
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采用木瓜蛋白酶水解不同浓度的大豆分离蛋白,研究了抗坏血酸对较低水解度(DH为3.7%)和较高水解度(DH为8.9%)酶解产物黏度、发泡性、发泡稳定性、乳化性和乳化稳定性的影响.结果表明:在水解度为3.7%的、浓度为7%的大豆分离蛋白酶解液中添加0.3%抗坏血酸,体系的黏度最大、乳化性最强、乳化稳定性最高;在水解度为8.9%的、浓度为3%的大豆分离蛋白酶解液中添加0.3%抗坏血酸,体系的发泡性最大;在水解度为3.7%的、浓度为7%的大豆分离蛋白酶解液中添加0.5%抗坏血酸,体系的泡沫体积比最大. 相似文献
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Evaluation of bitterness in enzymatic hydrolysates of soy protein isolate by taste dilution analysis 总被引:1,自引:0,他引:1
ABSTRACT: Although enzymatic hydrolysates of soy protein isolate (SPI) have physiological functionality, partially hydrolyzed SPI exhibits bitter taste depending on proteases and degree of hydrolysis (DH). To determine proteolysis conditions for SPI, it is important to evaluate bitterness during enzymatic hydrolysis. Taste dilution analysis (TDA) has been developed for the screening technique of taste-active compounds in foods. The objectives of the present study were to evaluate bitterness of enzyme-hydrolyzed SPI by TDA and to compare bitterness of SPI hydrolysates with respect to kinds of proteases and DH. SPI was hydrolyzed at 50 °C and pH 6.8 to 7.1 to obtain various DH with commercial proteases (flavourzyme, alcalase, neutrase, protamex, papain, and bromelain) at E/S ratios of 0.5%, 1%, and 2%. The DH of enzymatic hydrolysates was measured by trinitrobenzenesulfonic acid method. The bitterness of enzymatic hydrolysates was evaluated by TDA, which is based on threshold detection in serially diluted samples. Taste dilution (TD) factor was defined as the dilution at which a taste difference between the diluted sample and 2 blanks could be detected. As DH increased, the bitterness increased for all proteases evaluated. Alcalase showed the highest TD factor at the same DH, followed by neutrase. Flavourzyme showed the lowest TD factor at the entire DH ranges. At the DH of 10%, TD factor of hydrolysate by flavourzyme was 0 whereas those by protamex and alcalase were 4 and 16, respectively. These results suggest that TDA could be applied for the alternative of bitterness evaluation to the hedonic scale sensory evaluation. 相似文献
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Ruann J. S. de Castro Hélia H. Sato 《International Journal of Food Science & Technology》2014,49(2):317-328
Soy protein isolate (SPI) hydrolysates were prepared using microbial proteases to produce peptides with antioxidant activity. The process parameters (substrate and enzyme concentrations), hydrolysis time, functional properties and the effects of ultrafiltration were further investigated. The results showed that the soy protein isolate exhibited a 7.0‐fold increase in antioxidant activity after hydrolysis. The hydrolysis parameters, defined by the experimental design, were a substrate concentration of 90 mg mL?1 and the addition of 70.0 U of protease per mL of reaction. The maximum antioxidant activities were observed between 120 and 180 min of hydrolysis, where the degree of hydrolysis was approximately 20.0%. The hydrolysis increased solubility of the soy protein isolate; however, the hydrolysates exhibited a tendency to decrease in the interfacial activities and the heat stability. The SPI hydrolysates fractions obtained by ultrafiltration showed that the enzymatic hydrolysis resulted in samples with homogenous size and strong antioxidant activity. 相似文献
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Alcalase蛋白酶酶解高温豆粕制备水溶性大豆多肽 总被引:4,自引:1,他引:3
以氮溶指数为指标,应用Alcalase蛋白酶酶促降解高温豆粕,以获得高得率的水溶性大豆肽。酶促降解的优化实验结果表明:在加酶量1750U/g、底物浓度4%(w/w)、温度60℃、pH9.0的条件下酶促降解3h所得到的水解产物其氮溶指数达到了62.97%,比水解前提高了47.87%;酶解前后大豆蛋白的SDS-PAGE图谱表明:Alcalase蛋白酶可以催化大豆蛋白迅速地降解,水解1h后,7S蛋白的α-亚基,α’-亚基,β-亚基以及11S的酸性亚基已经完全消失,水解3h后,11S的碱性亚基也基本消失,且大多数的肽类分子量在20ku以下;与以大豆分离蛋白为原料制备的多肽相比,以高温豆粕为原料制备的多肽苦味值较低。 相似文献