Tenuazonic acid delays postharvest kiwifruit softening by inhibiting starch and cell wall degradation, and maintaining ROS homeostasis during ambient storage.

Abstract

Postharvest rapid softening compromises kiwifruit quality and marketability, necessitating effective preservative strategies. This study investigated the efficacy of tenuazonic acid (TeA) in delaying kiwifruit softening during ambient storage. TeA treatment significantly postponed kiwifruit softening by inhibiting starch and cell wall degradation. Specifically, TeA maintained the higher levels of starch, protopectin (PP), hemicellulose and cellulose, while reducing the water soluble pectin (WSP) content. These effects were attributed to the modulation of key enzyme activities, including β-amylase (BAM), pectate lyase (PL) and cellulase (Cx), as well as the regulation of gene expression (e.g., AcPME1, AcPME2, AcPL4, AcPL5, AcGal1, AcXTH14, and AcXTH17). Additionally, TeA enhanced the activity of superoxide dismutase (SOD) and peroxidase (POD), ascorbic acid (AsA) content, as well as the scavenging capacities of 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), thereby reducing the accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA). Collectively, our findings demonstrated TeA maintained kiwifruit quality and suppressed softening via inhibiting starch and cell wall degradation, and boosting the antioxidant system. This treatment shows promise for extending shelf life and delaying softening of kiwifruit.