Antioxidants associated with fruit senescence and human health: Novel orange-fleshed non-netted honey dew melon genotype comparisons following different seasonal productions and cold storage durations

Abstract

Orange-fleshed cantaloupe fruit ( Cucumis melo L. Reticulatus group) continues to raise food-safety concerns due to attachment of enteric bacteria to sites on the netted surface inaccessible to sanitation. Non-netted orange-fleshed honey dew fruit ( Cucumis melo L. Inodorus group) versus cantaloupe offers a safer and a healthier (nutritional content) option. Some commercially available non-netted orange-fleshed honey dew genotype fruit were compared for antioxidants associated with storage quality following autumn and spring production cycles, harvested at abscission (mature) and stored for up to 24 d at 5 °C or 10 °C. Spring versus autumn production generally yielded higher overall levels of 5-methyltetrahydrofolate (folic acid), calcium, malondialdehyde (MDA), and lipophilic total antioxidant capacities. ‘Orange Delight’ and ‘Orange Dew’, were generally superior to ‘Honey Gold’, ‘Temptation’ and a breeding line as they consistently demonstrated some of the highest levels of total ascorbic acid, β-carotene, and potassium. ‘Orange Delight’ and ‘Orange Dew’ were also among the cultivars with the highest activities of ascorbate peroxidase (EC 1.11.1.11), catalase (EC 1.11.1.6), and superoxide dismutase (EC 1.15.1.1). These two cultivars also exhibited the least increase in MDA (i.e. lipid peroxidation) during storage, suggesting antioxidant levels limited oxidative-related senescence compared to the other genotypes. Results indicate that there are significant differences in human health-related and storage quality-related phytochemical profiles between orange-fleshed honey dew cultivars and that high antioxidant levels are associated with reduced lipid peroxidation during fruit cold storage.