牛心肌蛋白酶解物的呈味特性与其结构关系研究

Protein hydrolysates from bovine cardiac muscle: Structure-taste relationship

利用10种食品级蛋白酶分别对牛心肌进行酶解处理,并探究酶解产物的呈味特性与肽结构之间的内在联系。分别采用Protease A、Protease P、Proteax、Flavourzyme、Alcalase、Papain、Bromelain、Protamex、Netutrase和Sumizyme BNP-L对牛心肌进行酶解,分析蛋白酶解物的水解度、分子质量分布、酶特异性,肽谱图与呈味特性的关系。研究结果表明,Protease A作为一种内外肽酶的复合酶制剂,是制备高鲜味、低苦味酶解物的最佳蛋白酶;然而,2种内肽酶(木瓜蛋白酶和菠萝蛋白酶)会导致蛋白酶解物产生苦味。偏最小二乘回归(partial least squares regression,PLSR)分析表明,酶解物的鲜味与低分子质量肽(<1 kDa)具有一定的正相关性,而其苦味与分子质量为0.5~1 kDa的肽组分呈正相关。蛋白酶特异性和肽谱图分析揭示,由于10种蛋白酶具有不同的酶切位点,导致相应的蛋白酶解物形成了不同的肽谱图,从而阐明蛋白酶解物的不同呈味特性。通过内肽酶和外肽酶联合酶解作用牛心肌,可以有效地减少蛋白酶解物的苦味并增加其鲜味。

Bovine cardiac muscle was hydrolyzed by ten food-grade proteases,namely Protease A,Protease P,ProteAX,Flavourzyme,Alcalase,Papain,Bromelain,Protamex,Netutrase and Sumizyme BNP-L,and the relationship between taste characteristics and peptide structure of the protein hydrolysates was investigated.The degree of hydrolysis,molecular weight distribution,enzyme specificity and peptide profile of protein hydrolysates were analyzed.Results showed that Protease A,a compound enzyme preparation with exopeptidases and endopeptidases,was the optimal protease for preparing low-bitterness and high-umami protein hydrolysates.However,two endopeptidases(Papain and Bromelain)elicited a bitter taste in the protein hydrolysates.Partial least squares regression(PLSR)analysis showed that the umami taste of protein hydrolysates was positively correlated with low molecular weight(<1 kDa)peptides,while the bitterness of protein hydrolysates was positively correlated with peptides with molecular weight of 0.5-1 kDa.The analysis of protease specificity and peptide profile revealed that ten proteases had different enzymatic cleavage specificity,which led to the formation of different peptide profiles,thus elucidating the different taste characteristics of protein hydrolysates.Endopeptidase combined with exopeptidase hydrolysis of bovine cardiac muscle can effectively reduce the bitterness and enhance the umami of protein hydrolysates.