Effects of High Hydrostatic Pressure Sterilization on the Quality of Selenium-rich Kiwifruit Juice

In this study, selenium-enriched kiwifruit 'Xu Xiang' was used as the raw material to systematically evaluate the effects of high hydrostatic pressure (HHP) sterilization on the quality of selenium-enriched kiwifruit juice through chemical analysis, electronic nose technology, and multivariate statistical methods, with thermal sterilization as a control. The results demonstrated that compared with untreated juice, thermal sterilization significantly reduced the selenium content of the juice (P<0.05), resulting in a selenium loss rate of 26.74%. In contrast, HHP-treated juice exhibited significantly lower selenium loss (P<0.05). Specifically, the selenium loss rate of juice treated with HHP (500 MPa, 3 min, one cycle) was only 2.59%. However, prolonged pressure holding time or additional cycles compromised selenium retention. Thermal sterilization also significantly decreased vitamin C (V_C) and polyphenol content, along with antioxidant activity (P<0.05), and caused degradation of chlorophyll a, chlorophyll b, and carotenoids. HHP treatment effectively preserved or even enhanced V_C, total phenols, total flavonoids, and antioxidant activity, while maintaining superior color stability. Although extending the pressure holding time reduced V_C and total carotenoid content, it significantly increased polyphenol levels. Furthermore, increasing the number of HHP cycles significantly diminished the electronic nose response to volatile compounds (P<0.05). In conclusion, HHP technology outperforms traditional thermal sterilization in preserving the nutritional quality and sensory attributes of selenium-enriched kiwifruit juice. It provides a theoretical foundation and technical roadmap for high-value processing of selenium-enriched agricultural products.