底物浓度对酸性蛋白酶水解面筋流变特性的影响

Effects of solid concentrations on rheological property of wheat gluten protein hydrolyzed by acid protease

摘要: 本文较系统地研究了PR23酸性蛋白酶催化不同浓度小麦面筋蛋白水解过程中酶解产物的表观现象、表观粘度、剪切应力和流变特性。研究结果表明:酶解体系中小麦面筋的浓度越高,反应液的p H上升越多,水分活度下降幅度越大。在整个酶解反应过程中,低底物浓度（8%³2%）酶解产物的表观粘度和剪切应力均会随着酶解时间的延长呈先升高后降低趋势;高底物浓度（40%）酶解产物的表观粘度和剪切应力均随着酶解时间的延长呈降低趋势。Ostwald-de waele模型可以很好的拟合酸性蛋白酶催化不同固形物浓度小麦面筋蛋白酶解产物。

Abstract: Apparent viscosity, shear stress and rheological properties of wheat gluten hydrolysates catalyzed by PR23, an acid protease, at different solid concentration were studied. Results showed that the increased solid concentrations of Glutenhydrolysates resulted in higher p H and lower water acitivity. Apparent viscosity and shear stress of wheat hydrolysates increased after 12 h of hydrolysis, and then decreased for solid concentration of 8%, 16%, 24% and 32%. The apparent viscosity and shear stress decreased with the reaction time for solid concentration of 40% during the whole hydrolysis process.Ostwald-de waele model can fit the wheat protein hydrolysis process for all solid concentration.