Investigate the effect of gelatin film containing probiotics of Bifidobacterium bifidum and Lactobacillus rhamnosus on the survival of Staphylococcus aureus and physicochemical properties of rainbow trout fillet

The aim of this study is to investigate the effect of gelatin film containing Bifidobacterium bifidum and Lactobacillus rhamnosus bacteria on the survival of Staphylococcus aureus bacteria inoculated into rainbow trout meat as well as its physicochemical characteristics for 12 days during storage at refrigerator. Staphylococcus aureus was inoculated into fish samples with a concentration of 106 log cfu/ml. Then the treatments (control group, rainbow trout samples packed with gelatin film, gelatin film containing each probiotic bacteria Bifidobacterium bifidum and Lactobacillus rhamnus with a concentration of 109 log cfu/ml separately and gelatin film containing both probiotics) were prepared. Samples were packed in polythene bags and stored in refrigerator. Probiotic bacteria viability and Staphylococcus aureus bacteria count, pH, TVB-N, PV and TBARS were evaluated. According to the results, the survival of probiotic bacteria showed a decreasing trend during the study, and it was found that the survival of Bifidobacterium bifidum bacteria in gelatin film treatment and gelatin film treatment containing both probiotics on the last day respectively 6.81 log cfu/g and 5.37 log cfu/g and the viability of Lactobacillus rhamnosus bacteria was also reduced by 7.43 log cfu/g and 6.31 log cfu/g respectively in the mentioned treatments. Compared to the control group, probiotic films controlled the microbial growth of fish fillets well, while the gelatin film treatment containing both probiotics had the lowest rate. Chemical tests also had an increasing trend and their changes in all treated fish fillets were significantly lower than the untreated group (P<0.05). It was found that gelatin films containing probiotics, especially gelatin films containing Lactobacillus rhamnosus and Bifidobacterium bifidum, which had worked more successfully, had an effective antimicrobial effect against Staphylococcus aureus bacteria, and this coating can increase the shelf life of rainbow trout and this The category of products has a good effect.