Composite film for edible oil packaging from carrageenan derivative and konjac glucomannan: Application and quality evaluation

Abstract

Abstract The composite film was developed from refined carrageenan (RC), semi-refined carrageenan (SRC) and konjac glucomannan (KGM) in various percent to study the functionality as active packaging for sesame oil. The physical, mechanical and functional properties of composite films were evaluated and shelf-life of sesame oil in the composite film also estimated during storage. Results showed that the thickness of the film increased to 0.066 mm from 0.034 with increasing ratio of KGM with carrageenan. The water vapor transmission rate of film made up of RC/KGM showed 91.4–110.8 g m−2 d−1, its counterpart SRC/KGM was 80–91.2 g m−2 d−1. The tensile strength and elongation at break were increased in 10% of KGM with RC and SRC. The composite films prepared were made into pouches with food grade adhesive and used for storing oil. Low WVTR resulted in the low oxidation rate and less production of peroxide values and iodine value in sesame oil while storage. It was also observed that no significant changes in the content of phytosterols of sesame oil were found during storage of three months (campesterol: 88.9–94.4 mg/100 gm, stigmasterol: 42.1–48.4mg/100 gm, and β-sitosterol 318.0–333.8 mg/100 gm). Therefore, the composite film functioned as an effective oil packaging material by preserving the active compounds in oil and hence this packaging material is an alternative to conventional plastic packaging material.