| Popis: |
Compositions that related to the secondary haze compositions in clarified apple juice were studied. Pressing treatment, pasteurization and enzymatic treatment were mainly investigated. Turbidity, contents of phenolics components, and that of soluble proteins in three batches of apple juice were monitored at intervals during the processing procedures. Pressing treatment resulted in increasing the turbidity and contents of total phenolics, condensed tannins, soluble proteins, but decreasing the level of low molecular- weight phenolics in apple juice. Pasteurization had effects on increasing the level of turbidity and decreasing the level of soluble proteins and had little effects on the level of phenolics components in apple juice. Enzymatic treatment resulted in decreasing the turbidity and the levels of catechin, epicatechin, chlorogenic acid, procyanidins B2 and condensed tannins and increasing the level of soluble proteins in apple juice. It will help to control the secondary haze formation in apple juice production. |
