摘要
为从秘鲁鱿鱼(Dosidicus gigas)中提取具有抗氧化活性且Fe2+螯合能力强的蛋白肽,研究采用复合酶解的手段通过响应面法得到了最佳酶解工艺,同时利用膜分离技术对酶解肽分级分离,考察了其氨基酸组成、红外光谱结构以及热稳定性的差异。实验结果表明,复合酶解的最佳工艺条件为:先调整反应体系为pH 7.0,添加木瓜蛋白酶酶解6 h;灭酶后调整pH为8.42,添加碱性蛋白酶酶解2 h,酶添加总量11800 U/g底物,两酶添加配比0.69(即木瓜蛋白酶:碱性蛋白酶=3.41%:4.96%),酶解温度保持55℃,此条件下酶解肽的Fe2+螯合能力为56.35%,DPPH.清除率为64.32%。经SDS-PAGE验证,必需氨基酸含量占氨基酸总含量(EAA/TAA)有显著性差异;红外光谱图显示各级抗氧化肽二级结构中包含了β-折叠、α-螺旋以及无规则卷曲,经酶解暴露出的官能团有羧酸类、氨基酸残基间的酰胺键以及少量的羟基;差示量热扫描结果表明分子质量越小,蛋白肽的耐热性越差。研究结果将为蛋白活性肽的精深应用提供理论支持。
In order to obtain the protein peptide with strong antioxidative activity and strong ferrous ion chelation ability from Dosidicus gigas,this study explored the optimal enzymatic hydrolysis process by means of enzymatic compounding and enzymatic hydrolysis,at the same time through the membrane separation technology to fractionation of enzymic peptide,surveying the amino acid composition,the differences between the infrared spectrum structure and thermal stability.The results showed that the optimal technological conditions for complex enzymatic hydrolysis were as follows:firstly,the reaction system was adjusted to pH 7.00,and papain was added for enzymatic hydrolysis for 6 h.After enzyme inactivation,the pH value was adjusted to 8.42,and alkaline protease was added for 2 h,adding 11800 U/g substrates,adding 0.69 of the two enzymes(papain:alkaline protease=3.41%:4.96%).The enzymatic hydrolysis temperature was maintained at 55℃.Under this condition,the chelating capacity of the enzymatic peptides was 56.35%,and the DPPH clearance rate was 64.32%.SDS-PAGE verified that the content of essential amino acids was significantly different in total amino acid content(EAA/TAA).Infrared spectra showed that the secondary structure of antioxidant peptides at all levels containedβ-folding,α-helix and irregular curling.The functional groups exposed by enzymatic hydrolysis included carboxylic acids,amide bonds between amino acid residues and a small amount of hydroxyl group.The results of differential calorimetry showed that the smaller the molecular weight,the worse the heat resistance of protein peptide.The results could provide theoretical support for the profound application of protein active peptides.
作者
缪佳瑜
林慧敏
李颖杰
邓尚贵
MIAO Jiayu;LIN Huimin;LI Yingjie;DENG Shanggui(College of Food and Pharmacy,Zhejiang Ocean University,Zhoushan 316022)
出处
《食品科技》
CAS
北大核心
2019年第12期131-139,共9页
Food Science and Technology
基金
浙江省自然科学基金项目(LY18C200007)
浙江省团队特派员项目(2017T1106).
关键词
秘鲁鱿鱼
抗氧化肽
响应面法
膜分离
Dosidicus gigas
antioxidant peptide
response surface method
membrane separation
作者简介
缪佳瑜(1996—),女,浙江舟山人,硕士研究生,研究方向为天然产物的提取与应用;通信作者:林慧敏
