Understanding the volatile organic compounds of 1-methylcyclopropylene fumigation and packaging on yellow-fleshed peach via headspace-gas chromatography-ion mobility spectrometry and chemometric analyses

Abstract

Headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and chemometric methods were utilized to analyze changes in volatile organic compounds (VOCs) of yellow-fleshed peach by 1-methylcyclopropylene (1-MCP) treatment and modified atmosphere packaging (MAP). Meanwhile, the storage quality of yellow-fleshed peach at room temperature (25°C) was also studied. Yellow-fleshed peach was treated by four methods, namely, nanomaterial packaging (NA), 1-MCP fumigation and nanomaterial packaging (1-MCP-NA), polyethylene (PE) packaging, and 1-MCP fumigation with polyethylene packaging (1-MCP-PE). Changes in the decay rate, firmness, browning index, soluble solid content, and titratable acid of the fruit were then measured at room temperature at 1, 4 and 10 days of storage. Thirty-two VOCs, including terpenoids, alcohols, esters, aldehydes, and ketones, were identified. Seventeen VOCs were found to be significant with predictive variable important in the projection (VIP) > 1 and p < 0.05 by analysis of variance and orthogonal projection to latent structure discriminant analysis (OPLS-DA). After 10 days of storage, the browning index of 1-MCP-NA group was 51.7%, which was lower than the control fruit (PE, 76.7%). Compared with other three treatments, 1-MCP-NA showed the better ability to delay and inhibit decreases in ester and aldehyde contents, and the ethanol content was lowest in the samples treated by 1-MCP-NA during storage. Differences among treatment groups were distinguished by principal component analysis (PCA) and hierarchical clustering heat map. The results showed that 1-MCP-NA could well maintain the quality and flavor stability of yellow-fleshed peach, and it had a good application prospect in the postharvest preservation of yellow-fleshed peach. PRACTICAL APPLICATION: In this study, 1-methylcyclopropylene (1-MCP) combined with nanomaterial (NA) packaging (1-MCP-NA) proved to have a better fresh preservation effect. 1-MCP-NA showed better ability to delay and inhibit decreases in ester and aldehyde contents by HS-GC-IMS technique. It provided a new strategy for postharvest storage of yellow-fleshed peaches.

Keywords: 1-methylcyclopropylene; chemometrics; headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS); modified atmosphere packaging; volatile organic compounds; yellow-fleshed peach.