Abstract:

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 ℃.

Key words: concentrated apple juice, pectinase, &alpha, -amylase, stability