Trisodium phosphate inhibits the shrinkage of passion fruit by suppressing ROS accumulation and mitigating oxidative damage

Abstract

Passion fruit experiences significant postharvest losses due to shrinkage during storage. Trisodium phosphate (TSP) is generally considered a safe substance by the US Food and Drug Administration, and is also defined as a food additive added to food in China. This study investigated the effects of trisodium phosphate (TSP) treatment on the harvested passion fruit during storage. The results indicated that 0.5 g L⁻¹ TSP treatment effectively inhibited passion fruit shrinkage, decreased the relative leakage rate, and reduced the levels of malondialdehyde, hydrohydrogen peroxide and O₂˙^- production rate, and protein carbonylation in harvested passion fruit during storage. Moreover, the application of TSP significantly enhanced the levels of antioxidants, namely ascorbate and glutathione, and augmented the activities of antioxidant enzymes, such as SOD, CAT, APX, and GR, in harvested passion fruit. Furthermore, TSP treatment upregulated the expression of SOD, CAT, APX, and GR genes, as well as stimulated the transcripts of key genes encoding METHIONINE SULFOXIDE REDUCTASE responsible for oxidation repair. Collectively, these findings highlight the promising potential of TSP as an effective approach to inhibit the shrinkage in passion fruit by suppressing ROS accumulation and alleviating oxidative damage.