崔美丽　刘永乐　俞健　李向红　罗阳阳　李彦　王发祥

摘要： 為筛选新型乳酸菌抗冻保护剂，通过复合蛋白质酶水解15 min、30 min、60 min、120 min、240 min制备了不同水解度的鲢鱼酶解产物，研究其相对分子质量分布、氨基酸组成、表面疏水性、活性巯基含量等特性及其不同酶解时间鲢鱼酶解产物和不同质量分数鲢鱼酶解产物对乳酸菌冻融存活率的影响。结果表明，不同酶解时间酶解产物相对分子质量主要在9.00×101～5.40×105，其氨基酸组成和含量基本相同，亲水性氨基酸比例占总量的68%;随着酶解时间增加，酶解产物的表面疏水性和活性巯基含量均呈先降后升趋势，其中酶解120 min的鲢鱼酶解产物表面疏水性最低，酶解30 min鲢鱼酶解产物的活性巯基含量最低;在不添加抗冻保护剂情况下，乳酸菌耐冻性能较差，4次冻融循环后存活率为22.82%;添加不同酶解时间鲢鱼酶解产物均对乳酸菌有一定的抗冻保护效果，其中酶解120 min的酶解产物对乳酸菌的抗冻保护效果最好，添加质量分数为4%时可使乳酸菌4次冻融循环后的存活率提高至85.20%。说明鲢鱼酶解产物是一种潜在的乳酸菌抗冻保护剂。

关键词： 鲢鱼酶解产物;乳酸菌;抗冻保护

中图分类号： TS201.3 文献标识码： A 文章编号： 1000-4440（2021）01-0197-07

Characteristics and cryoprotective effect of silver carp muscle hydrolysates on Lactobacillus plantarum

CUI Mei-li， LIU Yong-le， YU Jian， LI Xiang-hong， LUO Yang-yang， LI Yan， WANG Fa-xiang

（School of Chemistry and Food Engineering， Changsha University of Science and Technology， Hunan Provincial Engineering Research Center for Food Processing of Aquatic Biotic Resources， Changsha 410114，China）

Abstract： To screen new type cryoprotectant for Lactobacillus plantarum， the silver carp muscle hydrolysates （SCMHs） with different degrees of hyolysis were prepared by protamex that hydrolyzed for 15 min， 30 min， 60 min， 120 min and 240 min. The properties of SCMHs such as relative molecular mass， amino acid composition， surface hydrophobicity and active sulfhydryl content were studied， and the influence of SCMHs with different enzymolysis time and different mass percentages on the survival rate of L. plantarum after freeze-thaw were also studied. The results showed that the relative molecular mass of SCMHs with different enzymolysis time mainly ranged from 9.0×101 to 5.40×105. The composition and content of amino acids from different SCMHs were similar， and about 68% of the total amino acids were hydrophilic. With the increase of enzymolysis time， the surface hydrophobicity and active sulfhydryl content of SCMHs all presented the trend of decrease first and then increase. The surface hydrophobicity of SCMHs declined to its minimum after enzymolysis for 120 min， and the active sulfhydryl content of SCMHs reached its minimum after enzymolysis for 30 min. The freezing tolerant properties of L. plantarum was poor without the addition of cryoprotectant， and the survival rate of L. plantarum was 22.82% after four cycles of freeze-thaw. Addition of SCMHs with different enzymolysis time showed cryoprotective effect on L. plantarum， and SCMHs after enzymolysis for 120 min exhibited the best effect. The addition of SCMHs with a mass percentage of 4% could increase the survival rate of L. plantarum to 85.20% after four cycles of freeze-thaw. It is suggested that the SCMHs is a potential cryoprotectant for L. plantarum.

Key words： silver carp muscle hydrolysates;Lactobacillus plantarum;cryoprotective

鲢鱼 （Hypophthalmichthys molitrix） 是中国四大家鱼之一，由于具有价格低廉、生长速度快、养殖量大等优点，2018年养殖产量达3.858 9×106 t，在鱼类产量排名中仅次于草鱼[1]。但是鲢鱼肉薄肌间刺多、口感差、土霉味与鱼腥味重，严重影响了其食用品质。目前除加工成冷冻鱼糜外，仍然缺乏有竞争力的利用途径;同时，鲢鱼肉的营养价值高，有适宜比例的必需氨基酸，是优质的水产资源[2]，应合理地充分利用，避免浪费。……