超声波-曲酸复合处理对鲜切紫薯多酚氧化酶活性的影响

Effects of Ultrasonic-Kojic Acid Combined Treatment on Polyphenol Oxidase Activities in Fresh-Cut Purple Sweet Potato

在单因素试验的基础上,通过响应面法优化超声波-曲酸(Ultrasonic-kojic acid, US-KA)复合处理抑制鲜切紫薯多酚氧化酶(Polyphenol oxidase, PPO)活性的条件。单因素试验结果表明:超声功率360 W,超声时间9 min,曲酸溶液浓度30μg/mL时,抑制鲜切紫薯PPO活性效果最佳。响应面优化结果表明,超声功率320 W,超声时间544 s,曲酸溶液浓度28.3μg/mL时,所得PPO活性为2 017.8 U/mL,与未处理组相比,其活性降低了42.36%,与理论值2 015.9 U/mL的相对误差在0.94%左右,且此回归模型具有高度显著性,可以用于分析和预测超声-曲酸抑制鲜切紫薯PPO活性的最佳条件。

On the basis of single factor experiments,the conditions for inhibiting activity of polyphenol oxidase(PPO)in fresh-cut purple sweet potato by ultrasonic-kojic acid(US-KA)combined treatment were optimized by response surface method.The results of single factor tests showed that,the PPO activity in fresh-cut purple potato was inhibited best when ultrasonic power was 360 W,ultrasonic time was 9 min,and kojic acid solution concentration was 30μg/mL.The results of response surface experiment showed that,the PPO activity was 2017.8 U/mL when treated with 320 W ultrasonic power for 544 s at kojic acid concentration of 28.3μg/mL,which decreased by 42.36%comparing with the untreated group,the relative error with the theoretical value of 2015.9 U/mL was about 0.94%,and the regression model was highly significant.The results suggested that the model could be used in analyzing and predicting the optimal inhibition conditions of ultrasonic-kojic acid treatment on PPO activity in fresh-cut purple potato.