浓缩苹果汁加工中酶作用及贮藏稳定性研究

以红富士苹果浓缩汁为材料，采用单因素试验，研究果胶酶和α- 淀粉酶对还原糖、总酸、可溶性固形物等几个指标的影响，同时找出适合浓缩苹果汁澄清的果胶酶和α- 淀粉酶的酶用量、温度和时间。实验结果表明，在酶用量0.1%、温度50℃、时间1.5h 的条件下，浓缩苹果汁的澄清效果较明显。将加入果胶酶和α- 淀粉酶的浓缩苹果汁置于4℃和26℃条件下贮藏，测定其在贮藏过程中还原糖含量、总酸含量、pH 值和透光率等指标的变化。结果表明，在4 ℃贮藏条件下，随着贮藏时间的延长，还原糖含量、总酸含量、pH 值、透光率变化幅度较小，果汁营养成分保持较好，适宜贮藏。

Effect of Enzyme Treatment on Storage Stability of Concentrated Apple Juice

This study aimed to examine the effects of conditions for individual treatment of pectinase or α-amylase on reducing sugars, total acids, and total soluble solids (TSS) contents in Fuji apple juice concentrate during processing and the changes in reducing sugars and total acids content, pH and transmittance during storage at 4 ℃ and 26 ℃. Results showed that the treatment using pectinase orα-amylase with 0.1% dose at 50 ℃ for 1.5 h exhibited the optimal clarification to apple juice, and there were no obvious changes of reducing sugars, total acids, pH, and transmittance found in treated apple juice during storage at 4 ℃.