鲢蛋白酶解物理化特性及其对益生菌增殖的影响

Physicochemical Properties and Potential Prebiotic Activity of Silver Carp(Hypophthalmichthys molitrix)Protein Hydrolysates

【目的】探究不同酶解方式所得的鲢(Hypophthalmichthys molitrix)鱼肉蛋白酶解物的理化特性及对鼠李糖乳杆菌(Lactobacillus rhamnosus)、动物双歧杆菌(Bifidobacterium animalis)的潜在益生元活性。【方法】分别用复合酶Ⅰ(中性蛋白酶、碱性蛋白酶活性比1∶1)和复合酶Ⅱ(中性蛋白酶、碱性蛋白酶、风味蛋白酶活性比1∶1∶0.5)水解鲢鱼肉,获取不同酶解时长的酶解物,测定其水解度、分子质量分布和感官评价,经胃肠模拟消化(GID)处理后添加于培养基中培养两种益生菌,测定培养基的浊度。【结果】用复合酶Ⅱ水解4 h所得鲢鱼酶解物的水解度(DH)显著高于复合酶Ⅰ(P<0.05),可达27.2%。感官评价分值中,复合酶Ⅱ酶解产物的苦味分值比复合酶Ⅰ高。经模拟消化后,蛋白肽的小分子肽(<2 ku)组分比例超过90%。与空白组相比,该酶解物经胃肠模拟消化后按5 g/L剂量添加至益生菌培养基时,能显著促进益生菌在对数期的生长繁殖(P<0.05)。【结论】5 g/L模拟消化产物对鼠李糖乳杆菌和动物双歧杆菌的生长繁殖均有促进作用,鲢鱼肉蛋白酶解物有作为益生元的潜质。

【Objective】To investigate physicochemical properties and potential prebiotic activity of silver carp(Hypophthalmichthys molitrix)protein hydrolysates on Lactobacillus rhamnosus and Bifidobacterium animalis.【Methods】Silver carp fillet was hydrolyzed respectively by mixed proteasesⅠ(enzyme activity ratio of neutrase to alcalase is 1∶1)andⅡ(enzyme activity ratio of neutrase to alcalase and flavourzyme is 1∶1∶0.5)for different durations of time.The degree of hydrolysis(DH),molecular mass and sensory evaluation of the hydrolysates were determined.The hydrolysates were submitted to in vitro gastrointestinal digestion(GID)and the digested products were collected to culture L.rhamnosus and B.animalis,and the turbidity of the culture medium was measured.【Results】The DH of silver carp hydrolysates hydrolyzed by mixed proteaseⅡwas significantly higher than those hydrolyzed by mixed proteasesⅠ(P<0.05),with the maximum at 27.2%.In sensory evaluation,hydrolysates of mixed proteaseⅠwere bitter than that by mixed proteaseⅡ.The component of low molecular mass peptide(<2 ku)of silver carp hydrolysates after in vitro GID is more than 90%.Compared with the control group(MRS medium),the concentration of 5 g/L of digestion products can promote the growth of probiotics in logarithmic phase significantly(P<0.05).【Conclusion】5 g/L of digestion products could promote the proliferation of L.rhamnosus and B.animalis,which indicated that silver carp protein hydrolysates had the potential to be a prebiotics.