Abstract:In order to explore the influence of thawing conditions on the quality of apple juice, the physicochemical properties and volatile aroma components content of apple juice after thawing by 6 methods were analyzed. Besides, principal component analysis was used to evaluate the relationships between indexes. The results are as follow: Still air thawing took the longest time, followed by static water thawing and ultrasonic thawing. Compared with thawing at room temperature, thawing at low temperature took more time. There was no significant difference in color, soluble solid content, titratable acid content and the reducing sugar content of apple juice after thawing by different thawing methods (P > 0.05). The content of polyphenol in apple juice thawed in still air decreased significantly, while there was no significant difference in polyphenol content between static water and ultrasonic thawing (P > 0.05). The content of polyphenols in apple juice that thawing at low temperature was less than that of thawed at room temperature(P < 0.05). Under low temperature, 2-methyl butyl acetate was the most abundant among all volatile aroma compounds in apple juice, which accounted for 56%-64% of the total aroma components. However, the substance was not detected in that at room temperature, indicating that thawing at low temperature contributed to the retention of apple juice aroma components. This study showed that, under low temperature conditions, ultrasonic thawing can shorten the thawing time, and can retain the nutrients and color in apple juice.