黄秋葵浓缩汁加工过程中的品质变化

Quality Change of Okra Concentrate during Processing and Its Control Technology

采用果胶酶结合超滤对黄秋葵汁进行澄清处理,在不同温度下对澄清汁进行真空浓缩,以营养成分和酚类组成为指标,研究黄秋葵浓缩汁生产过程中的品质变化及加工工艺。结果表明:酶解汁的最佳制备工艺条件为:酶解温度41℃、酶解时间65 min、酶用量0.21 g/L,45℃为最佳的真空浓缩温度,孔径为67 ku的超滤膜进行超滤处理效果较好,透光率可达96.24%,黄秋葵浓缩汁中含有9种酚类物质。此外,还对黄秋葵浓缩汁生产过程中各类营养物质的变化进行研究,从而验证优化得到的各个生产技术参数是否能够很好地保留黄秋葵原有的营养成分。主要营养成分的含量在果胶酶处理时,含量增加4.81%~23.42%;超滤处理中明显损失,保留率为65.38%~83.59%;真空浓缩中损失较少,保留率均在93.56%~98.82%。澄清和浓缩过程是黄秋葵浓缩汁生产的主要过程,控制酶解、超滤和真空条件可为黄秋葵浓缩汁工艺化生产提供理论指导。

Pectinase clarification and ultrafiltration were used to clarify okra juice and the juice was vacuum concentrated at different temperatures. The quality change and processing technology of concentrated okra juice were studied in terms of nutrient composition and phenolic composition. The results showed that the optimum preparation conditions of the enzymatic juice were as follows: the enzymatic hydrolysis temperature was 40 ℃, the enzymatic hydrolysis time was 65 min, the enzyme dosage was 0.21 g/L, the optimal vacuum concentration temperature was 41 ℃, the ultrafiltration membrane with an aperture of 67 ku had a better ultrafiltration effect, the light transmittance was up to 96.24%. And the concentrated okra juice contained 9 phenolic substances. In addition, the changes of various nutrients in the production process of concentrated okra are also studied to verify whether the optimized production technical parameters can well retain the original nutritional components of okra. In the process of concentrated okra juice production, its main nutrients contents increased by 4.81%~23.42% during pectinase treatment. It was obviously lost in ultrafiltration, with a retention rate of 65.38%~83.59%;it was less lost in vacuum concentration, and the retention rate was between 93.56%~98.82%. The clarification and concentration processes are the main processes for the production of concentrated okra concentrated juice. Controlling enzymolysis, ultrafiltration and vacuum conditions can provide theoretical guidance for the technical production of concentrated okra concentrated juice.