Soluble soybean polysaccharide/gelatin active edible films incorporated with curcumin for oil packaging

An edible film based on soluble soybean polysaccharide (SSPS) and gelatin incorporating curcumin was fabricated as active packaging material for soybean oil. The effect of curcumin (Cur) on structural and physical properties of SSPS/gelatin films were investigated. Scanning electron microscopy revealed that curcumin was evenly distributed in the SSPS/gelatin matrix. Hydrogen bonding interactions between SSPS/gelatin and curcumin were unveiled by Fourier-transform infrared spectroscopy. The addition of curcumin (0 −0.20 %) significantly increased the tensile strength, temperature of maximum mass loss rate, yellow index, transparency value and water contact angle from 2.3 to 5.5 MPa, 249–252 °C, 2.04–183.07, 0.51–1.63, and 70.7–98.6°, respectively. The DPPH and ABTS radical scavenging activities of the SSPS/gelatin film containing 0.20% curcumin were 42.6 % and 99.6 %, respectively, which were remarkably higher than those of neat SSPS/gelatin film. The SSPS/gelatin/Cur composite films showed antibacterial activity against Escherichia coli and Staphylococcus aureus. The heat-sealed SSPS/gelatin/Cur pouch of soybean oil showed quick-dissolving property upon contact with hot water. Moreover, peroxide value results indicated that the SSPS/gelatin/Cur pouch could effectively delay the soybean oil oxidation under accelerated storage conditions. Therefore, the SSPS/gelatin/Cur composite films may be served as active packaging materials for edible oils.