Revealing the Effect of Different Sterilization Methods on the Quality of 'Hong yang' Kiwifruit Juice Based on OPLS-DA

To investigate the effects of different sterilization methods on the quality of kiwifruit juice. In this study, 'Hong yang' kiwifruit was used as raw material, and significance analysis and orthogonal projections to latent structures discriminant analysis (OPLS-DA) were used to evaluate the impacts of various sterilization treatments on several quality attributes of kiwifruit juice, including conventional physicochemical properties, color, polyphenols, flavonoids, vitamin C (V_C) content, and antioxidant activity. The results showed that thermal sterilization, high hydrostatic pressure (HHP) sterilization and food irradiation (FI) exhibited significantly different effects on the quality of kiwifruit juice. Among them, HHP sterilization achieved the optimal sterilization effect, which exerted positive effects on maintaining color stability and V_C content, improving the contents of functional active components and the antioxidant activity of kiwifruit juice. The three thermal sterilization methods had significant differences in their impacts on lactic acid content, citric acid content and V_C content of kiwifruit juice, while no significant difference was found in the influence on malic acid content. Thermal sterilization treatments could increase the contents of sucrose, total polyphenols and total flavonoids in kiwifruit juice, whereas the high-temperature short-time (HTST) sterilization group showed a decrease in fructose content. Food irradiation had the most significant impact on juice quality, which caused obvious color deterioration and a significant loss of V_C, the main active component, in kiwifruit juice. This study provides a theoretical basis for the scientific selection of sterilization technologies for kiwifruit juice production.