Effect of nanocomposite-based packaging and chitosan coating on the physical, chemical, and mechanical traits of strawberry during storage

Abstract

The combined use of fruit coating with nanocomposite packaging film is a novel technique for maintaining the quality and assisting more appropriate storage conditions. In the present study, a novel nanocomposite-based packaging was prepared by blending polypropylene and polyolefin elastomer with nanoclay. Strawberry fruit (Gavita cultivar) was evaluated for determining the effect of chitosan coating, packaging with polyethylene film and clay nanocomposite film on physical, chemical, and mechanical traits. Dependent variables including chemical (pH and Brix percentage), physical (color and weight loss), mechanical properties (firmness and elasticity modulus) and independent variables including two temperature levels (including 25 and 4 °C), two packaging levels (with polyethylene and with clay nanocomposite films), and two chitosan coating levels (including chitosan coating and without coating) were selected and analyzed based on the completely randomized multivariate factorial design. The results showed that main and interaction effects of studied factors were significant on color parameters, weight loss, pH, Brix percentage, firmness, and elasticity modulus. Finally, the outputs indicated that the coated samples packed with the clay nanocomposite film had the most optimal mode in terms of the changes in physical, chemical, and mechanical properties during the storage period. The variations of the dependent parameters at 4 °C were less than that at 25 °C during the storage period. The results showed that shear force and stress in nanocomposite film are higher than polyethylene film. Therefore, the coated samples packed with the clay nanocomposite film could be used to improve the shelf life of strawberry fruit.