1-MCP pretreatment combined with SO2 preservation pad delays postharvest senescence and softening of 'Shine Muscat' grapes by regulating cell-wall metabolism and antioxidant activity.

Quality deterioration of 'Shine Muscat' grapes involves tissue softening, aroma loss, and flavor alteration. This study investigated the effects of single and combined treatments of 1-methylcyclopropene (1-MCP) and preservation pads (SO2-pad) on physiological activities and quality changes in grapes during storage. The combined treatment exhibited delayed quality deterioration, with maintained fruit color, reduced respiration rate and weight loss. Moreover, the combined treatment best preserved characteristic terpenoid aroma compounds such as linalool while inhibiting off-flavor formation. Further, textural properties were greatly maintained by regulating cell wall metabolic enzyme activities and suppressing the accumulation of malondialdehyde (MDA) and H2O2. On 49 d of storage, the MDA content presented by the grapes submitted to the combined treatment was 0.71 μmol g-1, i.e., 46.2% lower than the control. The enhanced antioxidant system was evidenced by the elevated superoxide dismutase and catalase activities. This finding provides a viable treatment strategy for preserving fresh table grapes.