Ficus hirta fruits extract incorporated into an alginate-based edible coating for Nanfeng mandarin preservation

Abstract

An edible coating based on 1.5% sodium alginate (SA), 0.7% citric acid and 1.0% sucrose ester with and without Ficus hirta (FH) fruit extract was applied to Nanfeng mandarins to preserve their postharvest quality. Changes in decay rate, weight loss, quality parameters, respiration rate, and enzymatic activities of the coated and control samples were assessed at 10-day intervals for a 100-day storage period at 6°C. The decay rate, weight loss, respiration rate and maleicdialdehyde (MDA) content were much lower in the FH-SA coated samples than in the control group. During the middle and later periods of storage, Nanfeng mandarin treated with FH-SA coating maintained good fruit quality. The FH-SA coating treatment enhanced the activities of antioxidant and defense-related enzymes such as superoxyde dismutase (SOD), catalase (CAT), peroxidase (POD), chitinase (CHI), β-1,3-glucanase (GLU), and phenylalanine ammonialyase (PAL), and stimulated the accumulation of phenolic compounds. Our study suggests that FH-SA coating has the potential to enhance the long term quality and storage of Nanfeng mandarin.