纯生啤酒存放过程中泡沫稳定性与酵母蛋白酶A以及蛋白含量与组成变化的研究

Studies on the Changes of Foam Stability,Yeast Proteinase A and Protein Content and Composition in Unpasteurized Beer during the Storage

酵母蛋白酶A已经被证实对啤酒泡沫稳定性有负面作用。通过测定纯生啤酒存放过程中酵母蛋白酶A活性变化、泡持性衰减及蛋白含量的变化,进一步说明酵母蛋白酶A以及蛋白种类与含量对纯生啤酒泡沫稳定性的影响及其相互关系。对不同存放时期纯生啤酒样品中蛋白质进行电泳鉴定的结果显示,存放3月后的纯生啤酒中脂肪转运蛋白1(LTP1)完全消失,这一结果表明LTP1是影响啤酒泡沫稳定性的主要蛋白,该蛋白降解可能是酵母蛋白酶A作用的结果。

It is demonstrated that yeast proteinase A is detrimental to the foam stability of beer. The change of yeast proteinase A activity, decrease of head retention and change of protein content in unpasteurized beer were tested in this study. In order to furthermore indicated that proteiniase A and protein content were influenced foam stability seriously and theirelation ship within them. The pattern of SDS-PAGE of proteins in unpasteurized beer at different storage period showed that lipid transfer protein 1 （10 KDa） in unpasteurized beer after storage for 3 months was disappeared, this fact indicated that the lipid fransfer protein is a main protein related to the foam stability of beer. This protein might be probably decomposed by proteinase A.