超声-ε-聚赖氨酸盐酸盐复合处理对鲜切苹果的保鲜作用

为提高鲜切苹果品质、延长货架期，探究超声-ε-聚赖氨酸盐酸盐复合处理鲜切苹果的最优参数及其保鲜效果。采用Box-Behnken设计，以菌落增长数为响应值，通过响应面法确定超声-ε-聚赖氨酸盐酸盐复合处理鲜切苹果的最佳参数。根据菌落总数、霉菌和酵母、色差、V_C含量结果，评价超声-ε-聚赖氨酸盐酸盐复合处理对鲜切苹果贮藏期间的保鲜作用。结果表明，超声-ε-聚赖氨酸盐酸盐复合处理鲜切苹果的最优参数为:超声时间为10 min、超声温度为40 ℃、ε-聚赖氨酸盐酸盐浓度为0.2 g/L，切分前与切分后处理实际测定值分别为1.59 lg CFU/g、1.71 lg CFU/g，与预测值相对误差分别为3.92%、5.59%，拟合度高，模型可靠。利用优化的条件处理的鲜切苹果在4 ℃贮藏期间，细菌、霉菌和酵母增长速度显著低于（P<0.05）对照，V_C未受到明显破坏，切分前超声-ε-聚赖氨酸盐酸盐复合处理组色差上升速度低于对照组。响应面法优化的超声-ε-聚赖氨酸盐酸盐复合处理鲜切苹果是可行的，其中切分前超声处理效果较好，货架期比对照组延长4 d。

Preservation Effect of Ultrasonic-ε-Polylysine Hydrochloride Compound Treatment on Fresh-cut Apples

In order to improve the quality of fresh-cut apples and prolong the shelf life, the optimal parameters and fresh-keeping effect of ultrasonic-ε-polylysine hydrochloride compound treatment of fresh-cut apple were explored. Box-Behnken design was used to determine the optimal parameters of ultrasonic-ε-polylysine hydrochloride compound treatment of fresh-cut apples with the growth of the total number of colonies as the response value by response surface method. According to the results of the total number of colonies, mold and yeast, color difference and V_C content, the fresh-keeping effect of ultrasonic-ε-polylysine hydrochloride compound treatment on fresh-cut apples during storage was evaluated. The results showed that the optimal parameters of ultrasonic-ε-polylysine hydrochloride compound treatment for fresh-cut apples were as follows: Ultrasonic time 10 min, ultrasonic temperature 40 ℃, ε-polylysine hydrochloride concentration 0.2 g/L. The actual values of before and after cutting were 1.59 lg CFU/g and 1.71 lg CFU/g, respectively, and the relative errors with the predicted values were 3.92% and 5.59%, respectively, indicating the high degree of fitting and reliability of the models. During storage at 4 ℃, the growth rates of bacteria, mold and yeast in the fresh-cut apples treated with optimized conditions were significantly lower than that in the CK (P<0.05), and V_C was not significantly damaged. The color difference rise rate was lower in the ultrasound-ε-polylysine hydrochloride compound treatment group before cutting than that of the CK. The combined treatment of fresh-cut apples with ultrasonic-ε-polylysine hydrochloride optimized by response surface method was feasible, and the effect of ultrasonic treatment before cutting was better, and the shelf life was longer 4 days than that of the CK.