Effect of a galactomannan coating on mango postharvest physicochemical quality parameters and physiology

Abstract

Introduction . Films act as semi-permeable gaseous barriers capable of maintaining fruit postharvest quality; thus coatings consisting of non-traditional sources may represent an alternative tool for producers. The objective of our work was to investigate the effect of a galactomannan coating on postharvest quality and physiology of ‘Tommy Atkins’ mangoes. Materials and methods . Physiologically mature mangoes were divided into four lots and stored for 16 d. Control uncoated fruits (lot 1) were stored at ambient temperature (25 °C), the second lot was uncoated and refrigerated (14 °C), the third lot was coated and stored at ambient temperature, and the fourth lot was coated and refrigerated. Fruit were analyzed for physicochemical quality parameters, antioxidant enzymatic activity and lipid peroxidation. Results and discussion . Control fruit (lot 1) lost almost twice the weight of uncoated refrigerated (lot 2) and coated mangoes at both temperatures (lots 3 and 4); the fruit of lot 1 softened faster. Regarding the antioxidant enzymes, the activity of superoxide dismutase decreased throughout storage without statistical differences between treatments and catalasic activity was significantly inhibited under refrigeration. At ambient temperature, coating delayed the catalasic activity peak to day 12, which was coincident with the lowest lipid peroxidation degree, evidencing the association of free radical production and scavenging mechanisms. The galactomannan coating was efficient in reducing weight loss and delaying softening; thus, it maintained quality of ‘Tommy Atkins’ mangoes for a longer period of time than the control treatment during storage at ambient temperature. Refrigeration (14 °C) enhanced the performance of the galactomannan coating; it was effective in slowing down the metabolism and delaying softening to day 12.