Impact of Natural Polysaccharides Based Edible Coatings on Postharvest Physiology and Bioburden of Lycopersicon Esculentum

Abstract

Edible coatings are a promising postharvest quality management treatment for shelf-life enhancement and marketability of the agriculture products. This study aims to evaluate the effects of polysaccharide based edible coatings on the mean life of un-ripened tomatoes (Lycopersicon esculentum). Fruits were treated with three different edible coatings Aloe vera gel (T1), tragacanth gum (T2) and Aloe vera gel-tragacanth gum (T3) for postharvest preservation and the mean life was analyzed at 20ͦ C. They were then examined for various physiological, physiochemical and microbiological changes. The results revealed that all the applied formulations could retard the metabolic processes involved in tomato ripening. However, the combined effects of Aloe vera gel and tragacanth gum (T3) were most successful in positively maintaining the tomatoes since the fruits in this category recorded comparatively superior results for most of the analyzed parameters. They reached full maturity in 45 days compared to the control set which ripened in 14 days. This treatment led to a substantial postponement in weight loss, disease incidence, microbial growth and ripening index of tomatoes. A significant difference was observed in rate of color change among treated and untreated samples (P <0.05). For decay assessment, Uncoated samples decayed after 4 weeks while coated samples (T-3 tomatoes) remained healthy for 60 days. For weight loss assessment, the samples receiving treatments T1, T2, and T3 showed 16.23%, 14.45%, and 10.23 % weight loss at 20°C respectively. Thus, storage life and safety of tomatoes can be extended using Aloe vera-tragacanth gum based edible coating which has the potential to be used as natural preservative.