Effects of sterilization methods on pomegranate juice evaluated by descriptive sensory analysis and gas chromatography-mass spectrometry through partial least-squares regression

This study aimed to investigate the effects of different sterilization methods on the flavor characteristics and volatile compounds of pomegranate (PG) juice. We analyzed three PG samples, namely conventional-pasteurized, high-temperature short-time-treated, and ultrasonic-sterilized (US) juice samples. Fresh-pressed PG (FJ) sample was used as the control. A total of 33 volatile compounds and six sensory attributes (floral, fruity, earthy/musty, sweet, green, and cooked flavor) of PG samples were analyzed by gas chromatography-mass spectrometry and quantitative descriptive sensory analysis. Results revealed differences in the samples' sensory profiles. Compared with thermal-sterilization methods, the low temperature and relatively mild sterilization conditions of US considerably preserved the amount of volatile compounds. Partial least-squares regression (PLSR) was performed to identify the relationships among sensory attributes, volatile compounds, and sterilization methods. Results showed that limonene, linalool, hexanal, and 6-methyl-5-hepten-2-one contributed greatly to the key aroma of FJ and US. Meanwhile, p-Cymene, (E)-2-nonenal, naphthalene, and benzothiazole were significantly correlated with the cooked flavor after thermal sterilization. PLSR further confirmed that compared with thermal-sterilization methods, US may be more beneficial in preserving the volatile compound amount and sensory profiles of PG juice.