Differential Efficacy of Storage Temperature and Postharvest Treatment on Shelf Life and Quality of Avocado Fruit (Persea americana Mill.).

Abstract

Avocado fruit is a rich source of phytonutrients such as vitamins, minerals, carotenoids, carbohydrates, polyphenols and unsaturated fatty acids. However, due to its climacteric nature, fruits are highly susceptible to storage temperature, resulting in poor shelf life and reduced quality. In the present study avocado fruits (Accession CHES-HA-I/I) were stored at different low temperatures (5, 9 and 12°C with 90-95% relative humidity, RH) to identify optimum low temperature for cold storage. In a further experiment, avocado fruits were treated with 1-methylcyclopropene (1-MCP, 500ppb) and chitosan (0.5%) to extend the shelf life with better fruit quality. The results showed that storage temperatures had significant effect on physiological, biochemical and antioxidant activities of fruits. Lower physiological loss in weight (PLW), reduced respiration and ethylene production, and higher carbohydrates, protein and fat content were recorded in fruits stored at 9°C as compared to 12°C. Similarly, maximum antioxidant properties in terms of free radical scavenging activity (FRSA) and ferric reducing ability of plasma (FRAP) was found in avocado fruits stored at 9°C. It was also noticed that chilling injury was developed in fruits stored under 5°C. In addition, exogenous application of 1-MCP significantly reduced respiration and ethylene production rate at 9°C and extended the shelf life up to 42days with better fruit quality and more antioxidant activities. However, chitosan treated and control fruits had shelf life up to 28 and 21days respectively, with minimum nutritional content. From this study it is concluded that a storage temperature of 9°C and 1-MCP treatment significantly enhanced the shelf life of avocado fruits with better fruit quality as compared to other storage temperatures (5 and 12°C) and postharvest treatment (chitosan).