Effect of ultrasonic non-thermal sterilization on the volatile components of pumpkin juice

Abstract

The objective of this study was to investigate the effects of ultrasonic treatment on the aroma profile of pumpkin juice. Samples were treated according to the experimental design, with a numerically controlled ultrasonic instrument at an ultrasound frequency of 45 kHz under various conditions (treatment times of 10, 20, and 30 min, sample temperature of 25(± 2)∘C, and powers of 180, 240, and 300 W). The aromatic profiles of pumpkin juice showed that a total of 52 volatile components were detected in the 10 groups of pumpkin juices, including 16 alcohols, 11 alkane olefins, 6 aldehydes, 4 ketones, 4 esters, and 11 others. Alcohol compounds had the highest content among all volatile compounds; the most abundant were 1-Octen-3-ol, (E, Z)-3, 6-Nonadien-1-ol, 1-hexanol, and (Z) -3-Nonen-1-ol. Compared to the untreated samples of juices, ultrasonic treatment leads to the formation of new compounds or the disappearance of compounds found in the untreated samples. The findings presented in this study provide a deeper understanding of the application of ultrasound to enhance the volatile components of pumpkin juice.