Effect of edible coatings on eating and functional quality of Japanese plum cv. Santa Rosa

Plum (Prunus salicina L.) fruits of cv. Santa Rosa, were treated with SemperfreshTM (1:3), vegetable wax (1:5) and lac based (2:3) as an edible coating on the farm as well as after transportation to the laboratory (off-farm). Analytical determinations were made after 3, 6, 9, 12 and 15 days at 20 ± 2°C. All surface coatings, especially lac based wax were effective in inhibiting loss of moisture, ascorbic acid, total antioxidant activity and total phenols content. Lac based and SemperfreshTM displayed better efficacy in maintaining firmness followed by vegetable wax. At the end of storage period, lac based coated fruits showed higher fruit firmness (8.87 and 8.53 N) than control (6.50 and 6.30 N) in both on-farm and off-farm treatments, respectively followed by SemperfreshTM coated fruits (7.84 and 7.79 N). Maximum loss in titratable acidity (52%) was observed in control fruits whereas minimum loss was observed in on-farm treated lac based and SemperfreshTM coated fruits. The delay of the ripening process was also related to lower anthocyanin accumulation and least colour changes. After 15 days of storage, lac based coated fruits showed ∼13% lower anthocyanin content. The maximum total antioxidant activity and ascorbic acid content at end of storage were recorded in on-farm treated fruits with lac based coating (17.49 μmole Trolox/g and 3.92 mg/100 g, respectively), followed by SemperfreshTM and vegetable wax. Overall, results suggest that the surface treatments with lac based and SemperfreshTM coatings could effectively maintain the acceptability of plum fruits.