高速剪切对大豆分离蛋白限制性酶修饰的影响

研究高速剪切预处理对大豆分离蛋白限制性酶修饰制备等电点处高分散性蛋白的影响。以酶修饰产物的水解度、分散性为指标进行综合评价，揭示水解度与分散性的关系。结果表明，以常规酶修饰为对照，高速剪切处理能有效地促进大豆分离蛋白的酶修饰，在0.5～2.0h 范围内，随水解时间的延长，水解度逐渐增大，分散性也随之增加。该处理方式的最适参数为底物质量浓度100g/L、剪切速率6000r/min、剪切时间4min，该条件下酶修饰物的水解度从1.29% 提高到4.16%，等电点处分散性由20.62% 提高到46.82%，分别提高了3.22 倍和2.27 倍(P ＜ 0.05)，并将改性时间由4.5h 缩短至2.0h。

Effect of High-speed Shearing Pretreatment on Limited Enzymatic Hydrolysis of Soy Protein Isolate

The aims of the present study were to determine the effect of high-speed shearing before flavourzyme hydrolysis on the degree of hydrolysis (DH) of soybean protein isolate and to analyze the relationship between the DH and dispersibility of soy protein isolate (SPI) in an aqueous solution at the isoelectric point. The introduction of high-speed shearing effectively propelled the enzymatic modification of SPI with flavourzyme. As the hydrolysis time was prolonged from 0.5 to 2.0 h, both the DH and disperisibility of SPI showed a gradual rise. The optimal shearing treatment conditions were found to be: substrate concentration, 100 g/L; shearing rate, 6000 r/min; and shearing duration, 4 min, and the DH of SPI was increased from 1.92% to 4.16% and the disperisibility at the isoelectric point from 20.62% to 46.82% under these conditions, reaching 3.22- and 2.27-fold increments, respectively, but the time required for the completion of enzymatic modification was shortened from 4.5 to 2.0 h.