Packaging films formulated with gelatin and anthocyanins nanocomplexes: Physical properties, antioxidant activity and its application for olive oil protection

Anthocyanins (ACNs) nanocomplexes fabricated using chitosan hydrochloride (CHC) and carboxymethyl chitosan (CMC) were incorporated into gelatin film as a base formulation for the preparation of packaging films. The effects of ACNs-loaded CHC/CMC nanocomplexes on the film were investigated, with attention to the physical, antioxidant, and morphological properties of the resultant films. The results showed that the addition of ACNs-loaded CHC/CMC nanocomplexes improved the mechanical properties, thermal stability and antioxidant capacity of the films, whereas decreased the visible light transmission. Raman spectra analyses verified the interactions existed between gelatin and ACNs-loaded CHC/CMC nanocomplexes. Furthermore, the film composed of gelatin and ACN-loaded CHC/CMC nanocomplexes (Gel-CHC/CMC-ACN film) significantly delayed olive oil oxidative deterioration (21.2 meq O-2/kg of peroxide value at the 56th day) when compared with the films composed of gelatin only (Gel film, 28.4 meq O-2/kg of peroxide value at the 56th day) or ACN (unencapsulated form) and gelatin (Gel-ACNs film, 24.3 meq O-2/kg of peroxide value at the 56th day).This study revealed that a gelatin film with incorporated ACNs nanocomplexes can be used as a functional food packaging to protect foods with high fat content from oxidation.