Improved functionality of cinnamon oil emulsion-based gelatin films as potential edible packaging film for wax apple

This study discusses on the tailoring of cinnamon oil emulsion-based gelatin edible films that can encapsulate, protect and release bioactive compounds in food packaging applications. The effect of this cinnamon oil film for shelf-life extension and storage stabilities of wax apples (Syzygium samarangense L.) was evaluated over 12-day storage at refrigerated temperature (5 °C). Emulsion of cinnamon oil and surfactant at different ratios of 70:30 (ME1), 60:40 (ME2) and 50:50 (ME3) was incorporated into the films and the interactions between the emulsion and polymeric structure in films were analysed through physical, morphological and functional properties. The cinnamon oil emulsion-based gelatin films with a ratio of 70:30 exhibited significant increase in mechanical, water barrier, antioxidant activity and thermal stability. The increase in antioxidant activity of cinnamon oil films revealed that encapsulation of cinnamon oil in gelatin matrix better retains the bioactive compounds for food packaging applications. Cinnamon oil emulsion-based films significantly lowered the weight loss of wax apples (12.43%) compared to the control (unwrapped) wax apples (26.40%). Interestingly, this research indicates that encapsulation of bioactive compounds is governed by the ratio of oil to surfactant mixture in emulsion. It was proved that the film microemulsion with the 70:30 ratio of oil to surfactant (FME 70) have better overall performances as compared to the control (gelatin films) due to hydrogen and hydrophobic interactions with protein network of gelatin. In conclusion, cinnamon oil emulsion-based films could enhance and modify the functionality of protein-based films creating a biodegradable, sustainable and cost-effective food packaging materials.