摘要
该文研究了浓缩红枣汁中酶活残留对果汁乳饮料稳定体系的影响,研究表明添加含有果胶酶或纤维素酶的浓缩红枣汁会引起果胶或羧甲基纤维素钠(CMC)为稳定体系的产品粘度降低。采用粒度、粘度、离心沉淀率、lumisizer扫描来研究添加含有酶活残留的浓缩红枣汁对产品稳定性的影响。研究表明在生产果汁乳饮料时,如果添加含有酶活的果汁,产品稳定性会明显下降,表现在成品粒度增大、粘度下降、离心沉淀率和不稳定性指数成明显上升趋势。与此同时,建立以CMC溶液的粘度比值V_1≥80%作为判定浓缩红枣汁中无纤维素酶酶活残留的判定方法,建立以果胶溶液的粘度比值V_1~′≥85%作为判定浓缩红枣汁中无果胶酶酶活残留的判定方法。其中V_1为2%CMC溶液中添加果汁与不添加果汁的粘度比值;V_1~′为2%果胶溶液中添加果汁与不添加果汁的粘度比值。
This paper studied the effect of enzyme acitivity residues in concentrated jujube juice on the stability of fruit juice milk drink. The results indicated that the addition of concentrated jujube juice containing pectinase or cellulase will lead to a decrease of viscosity in final products,which using carboxymethylcellulose sodium(CMC)or pectin as stabilizer. The methods of static laser scattering,viscosity,centrifugation and lumisizer were used to study the effect of enzyme residues in concentrated jujube juice on the stability of product. The study showed that the addition of fruit juice containing active enzyme to the fruit juice milk drinks will result in larger particle size,smaller viscosity value,higher sedimentation after centrifugation and instability index,which imply the worse stability of final products. At the same time,viscosity ratio value(V_1 refers to CMC system and V_1~′ refers to pectin system)between 2 wt% hydrocolloid solution(CMC or pectin)with jujube juice concentrate and the one without jujube juice concentrate. The measurements were taken after enzymolysis under optimal condition. There is no cellulose or pectinase residues in the fruit juice when V_1 or V_1~′get the value more than 80% or 85% respectively.
引文
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