Flexibility, dissolvability, heat-sealability, and applicability improvement of pullulan-based composite edible films by blending with soluble soybean polysaccharide

This study aimed to prepare a heat-sealable, water-soluble, edible film based on pullulan (PUL)/soluble soybean polysaccharide (SSPS) for the portable packaging of convenience foods. The effects of the PUL/SSPS ratios on the microstructure, physicochemical properties, barrier properties, and mechanical properties of the PUL/SSPS films were explored. Fourier-transform infrared spectroscopy and X-ray diffraction showed an apparent hydrogen bonding interaction between SSPS and PUL in the PUL/SSPS films. As the SSPS proportion in the PUL/SSPS films increased, the water contact angle, moisture content, water vapor permeability, solubility, oxygen permeability, flexibility, and antioxidant activity increased, whereas light transmittance decreased. The heat-seal strength of the P9S1 film (PUL/SSPS ratio of 9:1) is slightly lower than that of the PUL film (p > 0.05). Furthermore, the application potential of the PUL/SSPS films for packaging peptide powder was evaluated. The P9S1 film exhibited a satisfactory packaging effect and was completely dissolved in water with low turbidity. Therefore, the P9S1 film is a promising packaging material for convenient powdered foods.