Quality and biochemical changes of fresh-cut melons in relation to maturity at harvest and packaging atmosphere

Fresh-cut melon, as a ready-to-eat product, offers a more convenient consumption compared to the whole fruit while representing a good source of carotenoids, ascorbic acid, and phenolics. Nonetheless, fresh-cut melons are very perishable and have a short shelf-life due to deterioration processes induced by cutting. Successful strategies for maintaining quality throughout shelf-life include selecting high-quality fruits at the appropriate ripeness stage and employing modified atmosphere packaging (MAP) with high O2 levels. This work aimed to study the effects of maturity at harvest, non-destructively assessed by time resolved reflectance spectroscopy (TRS), and of MAP (40% O2 + 10% CO2) on the quality attributes, nutraceutical properties, fermentative metabolites, and electrolyte leakage (EL) of fresh cut ‘Honey Moon’ melons. At harvest, 50 melons were measured by TRS, retrieving the absorption coefficient at 540 nm (μa540), then ranked by μa540 values and randomized in 5 groups corresponding to 5 times of shelf-life. Within each group, fruit ranked 1-3 (less mature – LeM) and 8-10 (more mature – MoM) were processed. Each melon was halved, with one half packed in air and the other in MAP, after being cut into 4 slices. Samples were analyzed after 1, 4, 7, 11, and 13 days of shelf-life at 4°C. The packaging atmosphere did not affect ascorbic acid (AsA) and soluble solids (SSC) content, EL, firmness and juiciness. Carotenoids were higher in air than in MAP while the opposite was found for ethanol and ethyl acetate, while no significant changes were observed for acetaldehyde. AsA and SSC were higher in MoM melons, while juiciness and h° pulp were lower. CO2 increased in air package, showing higher levels in MoM melons. EL increased up to 7 days in LeM melons and throughout shelf-life in MoM ones. Carotenoids slightly increased in LeM fresh-cut melons, while AsA decreased along shelf-life regardless of TRS maturity class and atmosphere.