Comparison and evaluation of aroma-active compounds for different squeezed Chinese bayberry (Myrica rubra) juices

Chinese bayberry is one of the most valuable fruits with unique flavor in China. Juice aroma can be affected by processing methods, especially squeezing. The present study aimed to differentiate the aroma profiles of bayberry juices under 4 squeezing conditions (freshly/frozenly squeezed at room temperature/4 degrees C). A total of 66 volatiles and 25 active aroma were identified as "green," "floral," "fruity" and "woody" odor. The contents of volatiles, including aldehydes, alcohols, and esters in the freshly squeezed groups were significantly higher than frozenly squeezed groups. It was found juices squeezed at room temperature had "fermented" flavor. The total content of volatiles in frozenly squeezed at room temperature was the lowest, especially beta-caryophyllene and humulene. By using GC-MS-O combined with principal component analysis, the bayberry juice freshly squeezed at 4 degrees C was of the best flavor quality, which would be used as optimal condition for squeezing process of bayberry fruits. Novelty impact statement This work further investigates the effect of 4 different squeezing conditions on volatile aroma compounds of bayberry juice. According to the results of GC-MS-O combined with principal component analysis, the contents of volatiles, including aldehydes, alcohols, and esters in the freshly squeezed groups, were significantly higher than frozenly squeezed groups, and the bayberry juice obtained by squeezing fresh fruit at 4 degrees C had the best aroma quality.