α-Lipoic acid treatment regulates enzymatic browning and nutritional quality of fresh-cut pear fruit by affecting phenolic and carbohydrate metabolism.

Fresh-cut pear fruit is greatly impacted by enzymatic browning, and maintaining quality remains a challenge. This study examined the impact of exogenous α-lipoic acid (α-LA) treatment on enzymatic browning and nutritional quality of fresh-cut pears. Results revealed that 0.5 g/L α-LA treatment effectively maintained color and firmness, and inhibited the increase in microbial number. The α-LA treatment also reduced MDA and H 2 O 2 contents, decreased PPO activity, and enhanced SOD, CAT, and PAL activities. The α-LA treatment notably upregulated phenolic metabolism-related gene expression, including PbPAL , Pb4CL , PbC4H , PbCHI and PbCHS , and then increasing total phenols and flavonoids contents. Furthermore, it also influenced carbohydrate metabolism-related gene expression, including PbSS , PbSPS , PbAI and PbNI , maintaining a high level of sucrose content. These findings indicated that α-LA treatment showed promise in reducing browning and enhancing fresh-cut pears quality, offering a potential postharvest method to prolong the lifespan and maintain nutritional quality. [Display omitted] • Flesh browning, MDA and H 2 O 2 contents were reduced by α-lipoic acid treatment. • α-Lipoic acid inhibited microbial growth and enhanced antioxidant capacity. • α-Lipoic acid maintained total phenols, flavonoids, and ascorbic acid contents. • α-Lipoic acid curbed PPO activity and enhanced PAL, CAT, and SOD activities. • α-Lipoic acid regulated genes expression in carbohydrate and phenolic metabolism. [ABSTRACT FROM AUTHOR]