Characterization of active nanochitosan film containing natural preservative agents

Objective(s): The aim of this study was to improve different characteristics including antibacterial, antioxidant and physical properties of nanochitosan film by incorporating Mentha spicata essential oil (EO) and methanolic pomegranate peel and grape seed extracts. Methods: The determination of the chemical composition of M. spicata EO was conducted by means of gas chromatography with mass spectrometry (GC-MS). Thickness, color, in-vitro antioxidant and antimicrobial properties of prepared films were evaluated.     Results: The most abundant constituents of M. spicata EO were carvone (78.76%), limonene (11.50%) and β-bourbonene (11.23%). The thickness of designated films and straight chitosan film were similar, however, the increasing value was observed for films containing M. spicata EO, pomegranate peel and grape seed extracts (P > 0.05). The lower lightness, higher redness and consequently a darker color was found in film incorporated with methanolic pomegranate peel and grape seed extracts. The highest antioxidant activity was found in nanochitosan enriched with the EO and grape seed extract. The antibacterial activities of all extracts and the EO were in the order: M. spicata EO > grape extract > pomegranate peel extract. Conclusions: The nanochitosan film incorporated with EO and extracts have shown good antibacterial and antioxidant activities which can be barrier against microbial and chemical contamination in food industries.