Effect of α‐Lipoic Acid Treatment on Sugar and Organic Acid Metabolism in Postharvest Strawberry Fruit

To investigate the regulatory effects of α‐lipoic acid (α‐LA) treatment on the senescence process of postharvest strawberry fruit, strawberries were immersed in 0.5 g/L α‐LA solution. By analyzing the contents of total soluble solids (TSS), titratable acidity (TA), predominant soluble sugars, and primary organic acids, as well as the activities and transcript levels of related key metabolic enzymes, the preliminary regulatory trends of α‐LA treatment on sugar and organic acid accumulation were investigated. The results showed that α‐LA treatment maintained higher levels of TSS and TA. Meanwhile, by regulating the activities of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI), along with the expression of related genes, α‐LA treatment maintained a higher net sucrose pool, while attenuating the sharp accumulation of glucose and fructose during late storage. Furthermore, α‐LA treatment inhibited the degradation of organic acids by regulating the activities of citrate synthase (CS), aconitase (ACO), malate dehydrogenase (MDH), and NADP‐malic enzyme (NADP‐ME), as well as their related gene expression levels. In conclusion, α‐LA treatment maintained the sweetness‐acidity profile of strawberry fruit during storage and delayed senescence, providing preliminary biochemical and transcriptional insights into α‐LA‐regulated sugar and organic acid dynamics.