Effects of the Combined Treatment of NO and HVEF on the Flavor Quality of Muscat Grapes During Cold Storage.

Although Muscat grapes are prized for their unique flavor and nutritional value, they are highly perishable and usually stored at low temperatures; however, refrigerated storage compromises their flavor quality. This study investigated the effects of sodium nitroprusside (SNP)-mediated NO treatment, high-voltage electrostatic field (HVEF) treatment, and a combination of the two treatments on the flavor quality of refrigerated Muscat grapes during storage at 0°C for 60 days. The results indicated that the combined treatment of SNP-mediated NO and HVEF was more effective than individual treatment and the control group in inhibiting the decrease in firmness, titratable acid (TA), and soluble solids content (SSC) of Muscat grapes during the cold storage (p < 0.05). In addition, GC-MS and GC-IMS identified 36 and 47 volatile compounds, respectively, and the HVEF + NO treatment effectively enhanced the content of pleasant aromas, such as fruit and floral notes, during storage, selectively retaining volatile compounds (geraniol, 2-ethyl-1-hexanol, limonene, 1-penten-3-ol), while suppressing the formation of off-flavors. Compared with the control group, HVEF + NO treatment exhibited higher activities of lipoxygenase (LOX), hydroperoxide lyase (HPL), alcohol dehydrogenase (ADH), alcohol acyltransferase (AAT), terpene synthase (TPS), and pyruvate decarboxylase (PDC) (p < 0.05). These findings demonstrated that HVEF treatment and SNP-mediated NO treatment effectively preserved the flavor quality of refrigerated grapes, offering a promising preservation strategy.