热处理辅助木瓜蛋白酶改善蛋清蛋白的起泡特性

Study on Modification of Egg White Protein With Heat-Assisted Enzymatic Hydrolysis Methods

摘要:

为获得起泡特性优良的蛋清蛋白制品，试验以新鲜鸡蛋蛋清为原料，采用热处理辅助木瓜蛋白酶有限酶解的方法来改性蛋清蛋白，通过单因素实验，分析了底物浓度、酶的添加量、酶解时间、酶解温度、酶解pH等因素对起泡能力、泡沫稳定性的影响，并在单因素实验的基础上，以起泡能力和泡沫稳定性为响应值，通过响应面分析和方差分析得出热处理辅助木瓜蛋白酶改性蛋清蛋白的最佳工艺条件：底物质量分数3%、热处理温度90 ℃、热处理时间10 min、酶的添加量3 500 u/g、酶解时间2.5 h、酶解温度55℃、酶解pH 7。在此条件下，蛋清蛋白的起泡力为1741.38%，泡沫稳定性为93.38%。与未改性的蛋清蛋白相比，起泡力提高了112.97%，泡沫稳定性提高了93.27%。泡沫流变学特性结果表明改性蛋白的泡沫储存模量G′是未改性蛋白的1.5倍，泡沫更加稳定。

Abstract:

In order to improve the foaming properties of egg white protein products，using fresh egg white as raw material，this paper adopted heat treatment to assist the limited papain hydrolysis of egg white protein. Then，the effects of substrate concentration，enzyme dosage，enzyme hydrolysis time，enzymatic hydrolysis temperature and pH on the foaming properties and the degree of hydrolysis of egg white protein were analyzed. Based on single factor experiment，the foaming ability and foam stability were selected as response values. Response surface analysis and variance analysis were employed to optimize process parameters. The optimum enzymatic hydrolysis conditions were as follows：substrate concentration 3%，heat treatment temperature 90 ℃，heat treatment time 10 min，enzyme dosage 3 500 u/g，enzyme hydrolysis time 2.5 h，enzymatic hydrolysis temperature 55 ℃ and pH 7. Under these conditions，the foaming ability and foam stability of egg white protein were 1741.38% and 93.38%. Compared with common egg white protein，the foaming ability was increased by 112.97%，and the foam stability was increased by 93.27%. The results of rheological properties of foam were shown that the storage modulus G 'of the foam of modified protein is 1.5 times higher than that of unmodified protein.