1-Methylcyclopropene Treatment on Phenolics and the Antioxidant System in Postharvest Peach Combined with the Liquid Chromatography/Mass Spectrometry Technique

In the present study, the potential effect of 1-methylcyclopropene (1-MCP) treatment on phenolics and antioxidant capacity in postharvest peach was assessed. Peach fruit (cv. Xiahui-8) treated with 1-MCP or without treatment was stored in 25 °C for 2, 4, 6, and 8 days. The phenolic composition and change trend were evaluated by liquid chromatography/mass spectrometry. The reactive oxygen species production and scavenging capacity against DPPH, O2• -, and HO• were determined. Gene expression of enzymes in the flavonoid biosynthetic pathway was assayed by quantitative reverse transcription polymerase chain reaction analysis. 1-MCP application inhibited the ethylene and CO2 production and stimulated the total phenol and total flavonoid contents. Total anthocyanin formation may be influenced directly or indirectly by the level of ethylene. The scavenging capacities of DPPH, HO•, and O2• - after 1-MCP treatment were enhanced. 1-MCP treatment affected the tissue color change, stimulated gene expression of PpaPAL, PpaCHS, PpaF3H, and PpaUFGT, and promoted the biosynthesis of flavonoids and stability of anthocyanin. PpaDFR and PpaUFGT played crucial roles in rapid color change stages. Kaempferol and kaempferol 3- O-galactoside increased distinctively during storage time.