关键词: 刺梨果汁, 褐变, 葡萄糖氧化酶

Abstract: 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.

Key words: Rosa roxburghii Tratt. juice, browning, glucose oxidase