Physical and antioxidant properties of films based on gelatin, gelatin-chitosan or gelatin-sodium caseinate blends loaded with nanoemulsified active compounds

The aims of this study were the development and characterization of active films based on gelatin (G), gelatin-sodium caseinate (G-Cs) and gelatin-chitosan (G-Ch) blends, applying active compounds (alpha-tocopherol, garlic essential oil and cinnamaldehyde) nanoemulsified in water (NACs). A microfluidization technique was used in the preparation of the O/W nanoemulsion. Following this, the emulsion system containing NACs was loaded into the film-forming solution. Films were prepared by the casting technique and thereafter characterized. Films based on the G-Ch blend plus NACs presented the lowest solubility and swelling and the highest hydrophobicity, as supported by the angle contact measurement. Analysis of the film microstructure obtained by SEM and FTIR exhibited a good compatibility among the G-Ch blend and showed that this matrix allowed a uniform distribution of the actives throughout the network. Films based on the G-Cs blend plus NACs showed the best antioxidant activity, highlighting its potential use as active packaging for shelf life extension of foodstuffs. (C) 2017 Elsevier Ltd. All rights reserved.