为提高酶解制备红肉火龙果果汁甜菜红素保留率和出汁率，探讨了酶添加量、酶解时间、酶解温度和底物pH等工艺因素对红肉火龙果果汁甜菜红素稳定性、出汁率和透光率的影响。在单因素试验结果基础上，采用Box-Behnken试验设计和响应面分析，以红肉火龙果果汁甜菜红素保留率为重要指标，结合考虑火龙果的出汁率和透光率响应值，运用期望函数同时优化多目标途径，优化了酶法制备红肉火龙果汁的工艺条件。结果表明：当果胶酶添加量为285 U/g，酶解温度46 ℃，底物pH为3.7，酶解时间2 h时，火龙果中的甜菜红素保留率可达到80.8%，出汁率可达到64.4%，透光率可达到89.5%，获得的酶解工艺参数在满足红肉火龙果果汁甜菜红素保留率高的同时，又有的高出汁率和透光率。经实验验证，实验值与预测相符。

In order to improve the retention rate of betacyanin and the juice yield of red pitaya juice prepared by enzymatic hydrolysis, the effects of enzyme concentration, enzymolysis time, enzymolysis temperature and substrate pH on the stability of betacyanin, juice yield and transmittance of pitaya juice were investigated. Based on the results of single-factor experiment, the Box-Behnken design and response surface analysis were used to optimize the enzymatic preparation conditions of red pitaya. The retention rate of red pitaya juice was used as the important index, and the transmittance of red pitaya were also used as response values. The function optimized the multi-objective approach and optimized the technological conditions for the preparation of red pitaya juice by enzymatic method. The results showed that when the enzyme concentration was 285 U/g, the enzymolysis temperature was 46 °C, the pH of the substrate was 3.7, and the enzymolysis time was 2 h, the retention rate of betacyanin in red pitaya juice could reach 80.8%, the juice yield could reach to 64.4% and the juice transmittance was 89.5%. The obtained enzymolysis process parameters could meet the higher retention rate of betacyanin of red pitaya juice , and also had higher juice yield and light transmittance. The experimental verification showed that the experimental value was consistent with the prediction.

国家荔枝龙眼产业技术体系项目（CARS-33）；广东省扬帆计划创新团队项目（2014YT02H013）