pH值对牛肉酶解物美拉德产物风味特性的影响

摘要

In this study,the effect of pH (5.0-6.5) on flavor characteristics of Maillard reaction products from enzmatic hydrolysates of beef (EBH-MRP) was studied.Results showed that as the pH increased,the sensory properties of EBH-MRP were mainly changed from meaty,salty to roast,and bitter flavor.The umami taste intensity of model blank chicken soup was enhanced more weakly,but the kokumi taste intensity was improved steadily.A significant positive correlation was observed between roast aroma and bitterness taste intensity.Excessive roast aroma implied the formation of bitter compounds,which not only could mask the meaty aroma of EBH-MRP but also inhibit its umami,kokumi taste and umamienhancing intensity.Quantitative analysis of flavor compounds demonstrated that meaty aroma intensity was neither correlated with the amount of the important precursor cysteine (Cys),nor with the contents of the key aroma substances.These findings demonstrated that meaty aroma was regulated by the interaction of various odorant compounds,which were generated by an extremely complex mechanism.In addition,a significantly positive correlation existed between the total content of nitrogen-containing heterocyclic odorants and roast aroma intensity.The high molecular weight EBH-MRP (＞ 3 000 D) was the major contributor to the bitterness taste.The increase of kokumi taste was associated with appropriate degradation of peptides.%本研究旨在探讨pH值(5.0～6.5)对牛肉酶解物美拉德反应产物(enzymic beef hydrolysate Maillard reaction product,EBH-MRP)风味特性的影响.结果表明:随着pH值的增加,EBH-MRP的感官特性主要从肉香、咸鲜味向烤香、苦味发展,对空白鸡汤的鲜味提升作用由强至弱,醇厚感提升作用稳步增强.苦味与烤香间存在显著的正相关关系,过度的烤香不仅掩盖肉香,还意味着苦味物质的生成,抑制味蕾对鲜味、鲜味提升作用及醇厚感的感知强度.结合风味物质含量的测定发现,肉香既不与重要前驱物半胱氨酸(Cys)的参与量具有相关性,也不与关键肉香味物质的含量具有相关性.说明肉香的感知是多类气味物质共同调控的结果,且生成机制极为复杂.此外,含氮杂环气味物质的总含量与烤香间有着极显著的正相关关系;大于3000D的糖肽交联产物对苦味具有一定贡献;适当的肽降解作用有利于醇厚感的提升.