原料热处理对玉米醇溶蛋白结构性质和酶解效率的影响

Effect of Heat Treatment on Structural Properties and Hydrolysis Efficiency of Zein

摘要:

以玉米黄粉为原料，在100 ℃和110 ℃温度下分别处理10 min、20 min和30 min后提取玉米醇溶蛋白，研究了原料热处理温度和处理时间对玉米醇溶蛋白提取率和部分结构性质的影响。同时，经加热处理的玉米醇溶蛋白用碱性蛋白酶Alcalase酶解，研究了热处理条件对醇溶蛋白酶解效率的影响。实验结果表明：随着加热温度的升高与处理时间的延长，玉米醇溶蛋白的提取率、游离巯基含量、表面疏水性和变性温度均升高。随着热处理时间的进一步延长，玉米醇溶蛋白聚集体的表面形貌发生改变，聚集体含量、游离巯基含量和变性温度持续升高，而玉米醇溶蛋白的提取率、表面疏水性和总变性焓降低。碱性蛋白酶Alcalase酶解经110 ℃处理30 min的玉米醇溶蛋白时，水解度比未处理玉米醇溶蛋白提高了9.80 %。

Abstract:

Zein was extracted from corn gluten meal (CGM) and treated at 100 ℃ and 110 ℃ for 10 min, 20 min and 30 min. The effects of heat treatment temperature and treatment time on extraction yield and some structural properties were investigated. Additionally, heat-treated zein was hydrolyzed by alkaline protease alcalase and the effect of heat treatment conditions on the hydrolysis efficiency was studied. The results showed that the extraction yield, amount of free sulfhydryl groups, surface hydrophobicity, and denaturation temperature of zein increased with prolonged treatment time and increasing heating temperature. As the heat treatment time further increased, the surface morphology of the zein aggregates changed, and the amount of zein aggregates and free sulfhydryl groups as well as the denaturation temperature increased continuously, while the surface hydrophobicity, extraction yield, and total denaturation enthalpy of zein decreased. When zein was subjected to alcalase hydrolysis after being processed at 110 ℃ for 30 min, the degree of hydrolysis increased by 8.29% compared with non-pretreated zein.