Pantnagar Journal of Research

Abstract

Plant tissues face considerable stress from mechanical damage, especially during cutting and handling, leading to changes in color, texture and flavor due to enzyme and substrate disruption. These challenges complicate the production of fresh-cut onions. Edible coatings offer a promising solution by forming a protective barrier against moisture loss, oxidation and microbial growth, while preserving product quality. In this research, chitosan was investigated as an edible coating for fresh-cut onion at varying concentrations (ranging from 0.5% to 1.5%). Other variables taken into consideration were dipping time (5 min to 15 min), ultrasonication power (50 to 250 W) and ultrasonication time (15 min to 45 min). Various coating properties such as thickness and viscosity were examined. Process conditions were optimized using response surface methodology and fresh cut onion was then coated with chitosan edible coating prepared with optimized processing conditions (Chitosan concentration- 1%, dipping time- 10 min, ultrasonication power- 150 W and ultrasonication time- 30 min). Weight loss, texture and microbiological analysis of the coated samples were done. It was observed that the fresh cut onion could retain their microbiological safety up to 15 days in comparison to untreated fresh cut onion which had shelf life of only 6 days under refrigerated conditions at a temperature of 5± 2 ⁰C. The coating could slow the rate of weight loss and texture loss in comparison to the raw samples. Hence, chitosan edible coating can be promising technology to produce fresh cut onion for up to 15 days in refrigerated conditions.