Divergent sensory-metabolic fingerprints in Longjing peach tea beverage: Decoding quality evolution under HPP versus UHT sterilization.

Abstract

Thermal sterilization often compromises beverage quality, making non-thermal sterilization a potential alternative. This study systematically compared the effects of high pressure processing (HPP) and ultra-high temperature (UHT) sterilization on the quality of Longjing peach tea beverage. Through sensory evaluation, physicochemical analysis, and multi-platform metabolomics combined with multivariate statistics, it was found that UHT significantly reduced acceptability, enhanced cooked off-flavor and astringency, and accelerated browning. In contrast, compared to UHT, HPP resulted in a sensory profile that was markedly closer to that of the untreated control, albeit with some observable quality deviations such as slight changes in flavor and specific metabolites. The L*, a*, and b* values of the beverage served as effective indicators for distinguishing sterilization methods and monitoring quality changes. UHT induced substantially greater alterations in metabolites than HPP, leading to a notable "flavor imbalance." Thirty-one flavor compounds associated with key sensory attributes were identified, revealing that the quality deterioration caused by UHT was mainly attributed to the loss of heat-sensitive flavor substances and the formation of Maillard reaction and thermal oxidation products. The impact of HPP, however, primarily resulted from the release and complexation of compounds under high pressure. This research elucidated the differential effects of the two sterilization techniques at both sensory and compositional levels, providing a scientific basis for process selection and quality monitoring in the production of high-quality fruit tea beverages.