低频超声波对大豆胰蛋白酶抑制素的处理效果

EFFECT OF LOW_FREQUENCY ULTRASONIC TREATMENT ON SOYBEAN TRYPSIN INHIBITOR

采用２０ｋＨｚ的低频超声波对大豆胰蛋白酶抑制素（ＳＴＩ）进行了处理．结果表明，超声波对经纯化了的鲍曼－贝尔克抑制素（ＢＢＩ）几乎不起钝化作用，对生豆奶中天然存在的ＳＴＩ的钝化效果要比对从大豆中提取纯化的ＳＴＩ好得多，说明纯化了的ＳＴＩ似对超声处理较稳定；豆奶中大分子蛋白组分１１Ｓ和７Ｓ的存在有助于ＳＴＩ的钝化；低频超声波对生豆奶中的ＢＢＩ似乎有轻微的激活作用；在生豆奶中添加半胱氨酸、亚硫酸钠和胃液素等添加剂对超声钝化ＳＴＩ有明显的促进作用．

Soybean trypsin inhibitor (SIT) is treated by the low_frequency ultrasonic of 20 kHz in this paper. The results show that the ultrasonic hardly activated the purified Bowman_Birk inhibitor(BBI), and the inactivating effect of ultrasonic on STI naturally exist in raw soy milk is more remarkable than that on STI extracted and purified from soybeans, which means that purified STI is quite stable to ultrasonic treatment. It is also be shown that the low_frequency ultrasonic somewhat has an activating effect on BBI in row soy milk and a remarkable effect of facilitating ultrasonic inactivation on STI in raw soy milk is taken by the addition of cysteine, sodium sulfite and pepsin.