摘要
采用脱脂乳平板透明圈法和麸皮培养基发酵测定法筛选到一株产蛋白酶活力较强的毛霉菌株HN201。以蛋白酶活力、游离氨基含量、活性肽活性为指标,对筛选得到的HN201菌株固态发酵豆粕产蛋白酶及大豆肽的最优条件进行研究。研究表明,28℃发酵培养96h时总蛋白酶活力最高;游离氨基含量随着培养时间的增加而增加,培养120h时达到77mmol/L,是发酵前的17倍;培养96h时产生的大豆肽具有最高还原能力,是相同浓度Vc还原能力的85%左右,是发酵前的1.8倍;培养48h时产生的大豆肽清除DPPH的能力最高,约是相同浓度Vc清除能力的60%,是发酵前的3.5倍;清除超氧阴离子自由基的能力随培养时间和温度的变化很小,发酵后无明显提高。SDS-PAGE电泳分析可知,豆粕发酵所产大豆肽分子量主要集中在10kD以下。
A new strain of Mucor,HN201,was screened using the method of clear zone resulting from hydrolysis of casein in plate and fermentation in wheat bran medium,which produced high activity of protease.The optimal conditions for solid-state fermentation of soybean meal byHN201 to were studied based on the protease activity,free amino content and antioxidant capability of the soybean peptide.The highest protease activity was achieved when fermentation temperature and time were 28 ℃ and 96 h,respectively.Free amino acid content of the fermented mixture increased to 77 mmol/L by prolonging the fermentation time to 120 h,which was 17 times higher than that of the unfermented soybean.The highest reducing capability and 2-diphenyl-1-picrylhydrazyl radical（DPPH？）-scavenging capability of soybean peptides were observed at 96 h and 48 h,respectively,which were 3.5 and 1.8 times respectively higher than those of the unfermented soybean meal.Comparative study showed that its reducing capability and DPPH？-scavenging capability were 85% and 60% of Vc with same concentration.And little changes in its scavenging ability on superoxide anion radical were found after fermentation.Electrophoresis analysis showed that the molecular weight of soybean peptide were lower than 10 kD.
出处
《现代食品科技》
EI
CAS
2010年第9期956-961,共6页
Modern Food Science and Technology
关键词
毛霉
豆粕发酵
大豆肽
Mucor strains
soybean fermentation
soybean peptides
