酶解产物浓度和油相体积分数对甘薯蛋白酶解产物乳化特性的影响

Effects of Hydrolysate Concentrations and Oil Volume Fractions on the Emulsifying Properties of Sweet Potato Protein Hydrolysates

本文研究了酶解产物浓度(0.10%、0.25%、0.50%、0.75%和1.00%,m/V)和油相体积分数(5%、15%、25%、35%和45%,V/V)对超高压下酶解制得甘薯蛋白酶解产物乳化液显微结构、乳化颗粒平均粒径(d4,3)、乳化活性指数(EAI)、乳化稳定性指数(ESI)和流变学性质的影响。当酶解产物浓度较低和油相体积分数较高时,乳化液的乳化颗粒均一细小。增加甘薯蛋白酶解产物浓度会使其乳化液的d4,3、EAI和ESI均逐渐降低;相反,增加油相体积分数会使乳化液的d4,3逐渐减小,EAI逐渐增大,而ESI则先降低后增加(p<0.05)。在酶解产物浓度低和油相体积分数高时,乳化液的初始表观粘度较大,且在1~100 s-1的剪切速率范围内均表现出了剪切变稀现象。酶解产物浓度和油相体积分数与乳化液的d4,3、EAI、ESI和流变学性质密切相关,是影响甘薯蛋白酶解产物乳化特性的重要因素。

The effects of hydrolysate concentrations （0.10%, 0.25%, 0.50%, 0.75%, and 1.00%, reV） and oil volume fractions （5%, 15%, 25%, 35% and 45%, V/V） on the microstructure, average particle size （oh.3）, emulsifying activity index （EAI）, emulsion stability index （ESI）, and rheological properties of the emulsion of sweet potato protein hydrolysates prepared under high pressure were evaluated. When the hydrolysate concentration was low and the oil volume fraction was high, the particles of emulsion were uniform and small. An increase in the protein concentration resulted in a gradual decrease in the oh,3, EAI and ESI of the emulsions. However, an increase in the oil volume fraction led to a gradual reduction of oh,3, and a gradual increase in the EAI of the emulsion. ESI initially increased but was then reduced （p〈0.05）. When the hydrolysate concentration was low and the oil volume fraction was high, the initial apparent viscosity of the emulsion was also high, exhibiting the phenomenon of shear thinning within the shear rate range of 1-100 sl. The hydrolysate concentration and the oil volume fraction were closely related to the d4,3, EAI, ESI, and rheological properties of the emulsion. These were the important factors affecting the emulsifying property of sweet potato protein hydrolysates.