Novel emulsion film based on gelatin/polydextrose/camellia oil incorporated with Lactobacillus pentosus: Physical, structural, and antibacterial properties

Edible films incorporated with probiotics and prebiotics have been presented an efficient strategy for food preservation. In this study, novel bioactive emulsion films fabricated from gelatin (GEL), camellia oil (CO, 50% and 100%, based on GEL), polydextrose (PD, 10% and 20%, based on GEL), and L. pentosus (109 CFU/mL) were evaluated by SEM, FTIR, DSC, mechanical, barrier, antioxidant and antibacterial properties analyses. Results suggested that the viability of L. pentosus was not affected by the addition of 50% CO, while significantly decreased by 100% CO (P < 0.05). The CO, PD and their combination significantly decreased the tensile strength and enhanced the elongation at break (P < 0.05). The water vapor barrier and UV-resistance properties of the films were improved with the incorporation of CO (P < 0.05). The FTIR and SEM suggested that CO was successfully distributed in GEL-based films through emulsification. The L. pentosus was also observed to be embedded in the GEL matrix by SEM. The GEL/CO50/PD20 film exhibited the highest DPPH free radical scavenging activity (46.18 ± 1.36%) and the largest inhibition zones against S. aureus (33.84 ± 0.31 mm) and E. coli (34.25 ± 0.69 mm). In conclusion, the novel probiotic emulsion film could provide a new method to develop active food packaging.