Effects of thermal and non-thermal sterilization on the quality and flavor of prune jam: An integrated analysis using E-nose, GC-MS, and GC-IMS.
Rui Yang, Shihao Huang, Wei Wang, Tongle Sun, Mingxun Ai, Xinyao Han +1 more
Food research international (Ottawa, Ont.)
Abstract
Conventional thermal sterilization often results in nutritional loss and flavor deterioration in prune jam, whereas the impact of emerging non-thermal technologies on such products has not been fully elucidated. This study systematically evaluated the effects of pasteurization (PT), ultra-high temperature (UHT), ultra-high pressure (UHP), and a low-voltage electrostatic field (LVEF) on the quality and flavor of prune jam, employing physicochemical analysis, sensory evaluation, and a combination of instrumental techniques, including electronic nose, GC-IMS, and HS-SPME-GC-MS. Results showed that all treatments successfully achieved commercial sterility. The non-thermal treatments, specifically UHP and LVEF, significantly inhibited color degradation (ΔE values of 3.21 ± 0.45 and 4.12 ± 0.38, respectively, vs. 11.11 ± 0.89 for UHT) and more effectively retained heat-sensitive nutrients like ascorbic acid (retention rates of 96.8% and 92.3%, respectively) and total phenolics (retention rates of 98.5% and 94.7%, respectively), along with superior sensory attributes. A total of 157 volatile organic compounds (VOCs), with 20 common to all samples, were identified. UHT treatment promoted the formation of off-flavor compounds such as furfural, whereas UHP and LVEF treatments preserved key fruity aroma components like hexanal. Partial Least Squares-Discriminant Analysis (PLS-DA) revealed that key VOCs with a Variable Importance in Projection (VIP) score > 1 were significantly correlated (P < 0.05) with nutritional and sensory indicators, thus uncovering the chemical mechanism behind the flavor variations. Overall, UHP demonstrated superior performance in preserving the physicochemical quality and characteristic flavor of prune jam compared with the other sterilization treatments evaluated in this study. LVEF also demonstrated considerable potential as an emerging technology. This study fills a knowle