Formulation and Characterization of Novel Composite Semi-refined Iota Carrageenan-based Edible Film Incorporating Palmitic Acid

摘要

Novel composite films based on semi-refined iota-carrageenan (SRIC) incorporating palmitic acid (PA) were prepared by an emulsification method. Palmitic acid (PA) as hydrophobic material was incorporated into semi-refined iota-carrageenan edible films in order to improve water vapor barrier properties. Composite SRIC-based films with varying concentrations of PA (10%, 20%, and 30% w/w) were obtained by a solvent casting method. Their mechanical and barrier properties were investigated. Results showed that the incorporation of PA in films caused a significant increase (p < 0.05) in thickness as the concentration of PA increased (from 10% to 30% w/w). The mechanical properties of semi-refined iota-carrageenan were also affected by PA incorporation; increasing the concentration of PA (from 10% to 30% w/w) in films umproved the tensile strength (TS). Interestingly, the TS value increased to a peak at 20% w/w PA. However, the TS value showed a decrease when PA were added at 30% w/w. Elongation-at-break (EAB) were significantly (p < 0.05) decreased when the concentration of PA in films increased (from 10% to 30% w/w). Furthermore, the incorporation of PA also affected the water vapor barrier properties of the films. Water vapor transmission rate (WVTR) of the composite semi-refined iota-carrageenan-based edible film decreased significantly (p < 0.05) as the concentration of palmitic acid increased (from 10% to 30% w/w). Composite SRIC-based edible film incorporating 30% w/w of PA presented better water vapor barrier properties as compared to other films with 10% and 20% w/w PA incorporation. Thus, formulation containing 30% w/w palmitic acid promoted films with a highly beneficial to improve water vapor barrier properties and it has the potential for food packaging applications.