Novel probiotic fermented edible film based on gum arabic/whey protein isolate/isomalt/glycerol incorporated with Lactobacillus rhamnosus: Physical, antibacterial, and fresh pork preservation properties

Some probiotic films have not shown satisfactory antibacterial performance, which limits their application in food. The purpose of this study is to improve the antibacterial activity of probiotic film by using probiotics to ferment the film solution, and to solve the problem of weak antibacterial performance of probiotic film. In this study, the solution composed of gum arabic/whey protein isolate/isomalt/glycerol was firstly fermented by Lactobacillus rhamnosus (L. rhamnosus) HN001, and then prepared into probiotic fermented films. The effect of probiotic fermentation on the films properties was systematically evaluated in this study. These results demonstrated that probiotic fermentation enhanced the mechanical strength, water barrier properties, thermal stability, and antioxidant activity of the films. According to the scanning electron microscopy (SEM), the probiotic-fermented films exhibited a more compact and coherent structure. Characterization of the films revealed that probiotic fermentation improved the compatibility between the film components and altered the conformation of whey protein. Compared to the non-fermented probiotic films, the probiotic-fermented films exhibited an 11% increase in the inhibition rate against Staphylococcus aureus and a 21% increase in the inhibition rate against Salmonella. The probiotic-fermented films successfully delayed the spoilage of fresh pork stored at 4 °C, effectively inhibiting microbial growth and reproduction, demonstrating a more effective preservation effect than the non-fermented probiotic films. This study provides an effective and convenient method for improving the antibacterial properties and preservation effect of probiotic films.