Abstract

Tomato (Lycopersicon esculentum Mill.) fruits due to their high moisture content are spoiled and deteriorate in short period of time. Once fruits are harvested, respiration and transpiration are the two major physiological processes that significantly affect storage life and quality of the fruits. However, effects of these processes can be minimized through optimizing harvesting stage of fruits and applying physical barriers for oxygen diffusion and moisture migration. The aim of this work was to investigate the combined effect of stage of harvesting of fruits and application of edible coating materials on storage life and quality of tomato fruits. Treatment combinations were the three harvesting stages of the fruits (mature green, turning and light red stages) and two coating materials (pectin and chitosan with control). Treatments were laid out in a completely randomized design with three replications. Sample fruits were evaluated periodically for different parameters. The study showed that, coating of tomato fruits delayed the ripening process with better fruits quality than uncoated ones. Combined treatment combinations resulted in a significant delay in the change of weight loss, disease incidence, disease severity and ripening index as compared to control fruits. Moreover, in terms chemical parameters, coated fruits revealed higher amount of ascorbic acid, lycopene and phenolic contents. Fruits coated with either chitosan or pectin at turning stage of maturity showed relatively better results for most of the quality parameters. Maximum shelf life was observed for fruits harvested at turning stage coated by pectin (17 days) and chitosan (16 days) films than control (10 days) at the same stage of maturity. Therefore, storage life of the fruits with better quality can be extended by combining optimum stage of harvesting with use of edible coating materials.

Key words: Tomato, harvesting stage, edible coating, pectin, chitosan, storage life.