响应面优化葡萄糖氧化酶抑制刺梨果汁褐变工艺

以刺梨果汁为原料，研究葡萄糖氧化酶对刺梨果汁在加工贮藏过程中主要褐变因素的影响，为抑制刺梨果汁褐变，探索合适的工艺条件。采用Box-Behnken响应面试验设计优化葡萄糖氧化酶抑制刺梨果汁褐变最佳工艺条件为酶添加量28 U/L、作用时间38 min、作用温度37 ℃，此条件下得到刺梨果汁褐变指数为0.122±0.001，葡萄糖氧化酶能显著消耗刺梨果汁中溶解氧（7 d后溶解氧含量为0.523 mg/L），远低于对照组（5.991 mg/L，P＜0.05），抑制刺梨果汁氧化反应。此外，葡萄糖氧化酶处理可有效保存VC和氨基态氮含量，减缓褐变中间产物5-羟甲基糠醛的产生，降低褐变指数的增长速率（P＜0.01），有效抑制刺梨果汁褐变的发生。

Optimization of Browning Inhibition of Rosa roxburghii Tratt. Juice by Glucose Oxidase Using Response Surface Methodology

This research was conducted to study the effect of glucose oxidase on the browning inhibition and quality of Rosa roxburghii Tratt. juice during processing storage and to explore the conditions for browning inhibition. Using Box-Behnken design combined with response surface methodology, the optimal conditions for browning inhibition were determined as 28 U/L, 38 min and 37 ℃ for enzyme dosage, hydrolysis time and temperature, respectively, yielding a browning index of 0.122 ± 0.001. Under these conditions, glucose oxidase significantly depleted the dissolved oxygen in R. roxburghii Tratt. juice (P < 0.05), decreasing to a level (0.523 mg/L) significantly (P < 0.05) lower than that of the control group (5.991 mg/L), and as a result inhibited the oxidation of R. roxburghii Tratt. juice. Moreover, glucose oxidase treatment could better maintain the VC and amino nitrogen contents of R. roxburghii Tratt. juice, slowed down the formation of the browning intermediate product 5-hydroxymethylfurfural (5-HMF), blocked the increase in browning index (P < 0.01), and effectively inhibited the occurrence of R. roxburghii Tratt. juice browning.