果浆酶和果胶酶对猕猴桃出汁率的影响

为制取猕猴桃汁,通过单因素和正交试验,以出汁率、VC保存率和果汁色泽香气变化为指标,用果浆酶和果胶酶对猕猴桃进行酶解处理,探索更适合的猕猴桃制汁工艺条件。结果表明:两种酶都能大幅提高猕猴桃的出汁率,果胶酶酶解条件较剧烈,虽出汁率较高,但对VC含量和果汁色泽香气影响较大;果浆酶酶解条件较温和,总体指标较好,最佳酶解条件为酶解温度30℃、果浆酶加酶量10000U/kg、酶解时间2h、出汁率0.853mL/g,VC保存率67%。果浆酶更适合猕猴桃果汁的制取。

Effect of Enzymatic Treatment with Pectinex or Pectinase on Juice Yield of Kiwi Fruit

Pectinase and pectinex were used separately to produce kiwifruit juice from kiwi fruit pulp in the current study.To find a better enzymatic pretreatment for the production of kiwifruit juice,one-factor-at-a-time and orthogonal array design methods were used to optimize hydrolysis conditions based on juicr yield,VC preservation rate,changes of juice color and aroma.The results showed that both enzymes could improve the yield of kiwi fruit juice substantially.However,pectinase required more intense hydrolysis conditions and had greater effect on vitamin C content and juice color and aroma compared to pectinex.Mild conditions were required for pectinex treatment,which resulted in better overall quality index of kiwifruit juice.The optimal conditions for pectinex hydrolysis were 2 h of hydrolysis at an enzyme dose of 10000 U/kg and 30 ℃.Under these conditions,the juice yield and vitamin C preservation rate were 0.853 mL/g and 67%,respectively.This study demonstrated that pectinex is more suitable for the production of kiwifruit juice.