Development and characterization of active packaging nanofiber mats based on gelatin-sodium alginate containing probiotic microorganisms to improve the shelf-life and safety quality of silver carp fillets

The current study aimed to incorporate Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus casei, and Lacticaseibacillus rhamnosus (similar to 10 log CFU/ml) into gelatin-sodium alginate nanofibers via electrospinning process in order to investigate the influence of fabricated mats on the growth of food-related pathogenic bacteria and shelf-life extension of refrigerated silver carp fillets in a two-week period. The strain-loaded nanofibers exhibited lower water vapor permeability, swelling index, moisture content, and tensile strength than the straight nanofibers (P < 0.05). The survival order of probiotics in nanofibers stored at 4, 25, and 37 degrees C for 14 days are as follows: L. acidophilus (8.15-9.35 log CFU/g) > L. reuteri (7.42-9.24 log CFU/g) > L. casei (7.41-9.13 log CFU/g) > L. rhamnosus (7.37-8.92 log CFU/g). The probiotic mats significantly delayed the growth of Vibrio parahaemolyticus, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in silver carp fillets in comparison with the unpackaged sample (P < 0.05). Moreover, the designated nanofibers improved the bacterial, chemical, and sensory properties of treated samples in comparison with the unpackaged samples throughout the study period. Our findings indicate that gelatin-sodium alginate nanofibers are a suitable platform for the protection of living probiotics and present an alternative procedure for retarding the growth of foodborne pathogens and extending the shelf-life of fresh carp fillets under refrigerated storage conditions.