Improving the shelf-life stability of apple and strawberry fruits applying chitosan-incorporated olive oil processing residues coating

Recently, antioxidants and antimicrobials incorporation into edible films are one of the novel techniques in food processing. This study is aimed at determining the applicability of olive oil residues extracts (OOR) incorporated with chitosan (CH) films for improving the shelf-life stability of apple and strawberry fruits. After OOR incorporating, antimicrobial and physical parameters of each formula were investigated. Then, the keeping quality parameters of infected cold stored apple and strawberry were assayed. Indeed, addition of OOR to CH led to increase its antifungal and antibacterial activities against the tested strains. Regardless, the inhibition percentage was clearly high against Penicillium expansum compared with Rhizopus stolonifer in vitro and in vivo. Moreover, 20 g kg(-1) OOR was slightly affected the film appearance; but significantly influenced the thickness and solubility. Amazingly, the CH-OOR was reduced significantly the gradual decline both coated fruits in their microbiological features. Therefore, integration of OOR into CH can be used to improve the inhibition properties of CH based film against spoilage and pathogenic strains. The olive leaves extract exhibited valuable efficiency than olive pomace extract in both in vitro and in vivo. Moreover, the result suggested that CH-OOR could be explored as a novel and potential natural edible coating to substitute the synthetic agents for apple and strawberry coating. (C) 2016 Elsevier Ltd. All rights reserved.