Investigation of physicochemical properties, antimicrobial and antioxidant activity of edible films based on chitosan/casein containing Origanum vulgare L. essential oil and its effect on quality maintenance of cherry tomato.

Edible coatings prevent physicochemical and biological food deterioration. Using bioactive compounds like essential oils can enrich films. In this study, edible films from chitosan (C), casein (Z) and oregano (OEO) were developed, and their physicochemical, barrier, antimicrobial, antioxidant, and structural properties (FTIR, SEM) were investigated. The CZ ratio had good mechanical and inhibitory properties, and OEO improves flexibility, barrier, hydrophobic, antimicrobial, and antioxidant properties. The physicochemical and microbiological properties of cherry tomatoes were affected by CZ and CZO coatings. Coated fruits were stored at 4 °C for 32 days. The best results for weight loss, shrinkage, and titratable acidity were found to be 17.88%, 31.12%, and 0.15% in CZO coated cherry tomatoes, respectively.The TMAB of CZO coated fruits was less than detectable and the fungal growth was inhibited for 28 days. Accordingly, by adding OEO to chitosan/casein coatings, the spoilage process of cherry tomatoes was delayed for long-term storage.