Physicochemical changes in ‘Santa Rosa’ plum fruit treated with melatonin during cold storage

Abstract

This study was conducted to investigate the effects of melatonin treatments on biochemical compounds and postharvest quality plum cv. “Santa Rosa” during storage at 1 °C for 40 days. The plums were dipped in 0, 1, 10, 100 and 1000 µmol l−1 melatonin solution immediately after harvest. The changes of plums were assessed at 10-day intervals by evaluating the following quality parameters: weight loss, firmness, soluble solids content (SSC), titratable acidity (TA), SSC:TA, ascorbic acid content, total anthocyanin content, total phenolic content, antioxidant activity and decay rate. The results showed that treatment of melatonin at 100 and 1000 µmol l−1 was effective in reducing weight loss and maintaining greater firmness. However, low doses of melatonin treatment had no effect positively on carbohydrate, acids, biochemical compounds and spoilage. During cold storage, ascorbic acid content, total phenolic content and antioxidant activity were greater in 100 and 1000 µmol l−1 melatonin treated plums than the control and other doses. Meanwhile, 1000 µmol l−1 melatonin substantially reduced decay rate, which result from significantly higher biochemical compounds. These findings suggested that especially 1000 µmol l−1 melatonin treatment may be useful technique to extend the postharvest life of plum with acceptable fruit quality.