Exogenous polyamine treatment preserves postharvest quality, antioxidant compounds and reduces lipid peroxidation in black plum fruit

Abstract

Black plum (Syzygium cumini L. Skeels) is a tropical and sub-tropical fruit having several medicinal properties, especially in curing diabetes. Due to non-climacteric nature, the fruit is harvested at ripe stage. However, presence of thin skin and rapid softening make the fruit highly susceptible to moisture loss and microbial attack, which drastically reduce its shelf life. Black plum, due to its high perishability cannot be stored more than 2 – 3 days at ambient conditions. In the present study, the effect of pre-storage polyamines treatment on quality and storability of black plum fruit was investigated. Ripe fruits were treated with putrescine (PUT) and spermine (SPM) each at 0.5 mM and 1.0 mM concentration by immersion method while, control fruit were treated with distilled water. The fruit were stored at ambient conditions (27 ± 3 °C, 85 ± 5% RH) for 6 days. Results revealed that 1.0 mM PUT treatment was most effective in minimizing weight loss and spoilage of about 1.5-fold compared to control. The treated fruits also retained higher anthocyanins and minimized lipid peroxidation than control. The loss of bioactive compounds like total phenolics, flavonoids, ascorbic acid and antioxidant capacity also minimized in response to polyamine treatments. The soluble solids content retained higher in 1.0 mM PUT-treated fruits but, polyamine treatments did not affect acid content. The findings of the study can be beneficially exploited in extending storability, long distant marketing and reducing postharvest loss of black plum fruit.