Probiotic products are beneficial food items that promote health. In the production of probiotic meat products, the main challenge is the exposure of probiotic bacteria to the heat treatment process during cooking. The aim of this project is to enhance the resistance of Lactobacillus plantarum PTCC1896 and Lactobacillus fermentum PTCC1744 probiotic bacteria through the use of hydroxypropyl methylcellulose and maltodextrin coatings, as well as optimizing the ratios of these two coatings. Finally, the effect of these coatings on the survival of these bacteria during the fermentation cooking process and under simulated gastrointestinal conditions will be investigated to produce a product that preserves its probiotic properties. In the conducted research on the production of fermented probiotic sausages without nitrite, a micro-encapsulation method by spray drying was used to enhance the resistance of these two bacteria. Different percentages of the mentioned coating materials were used for the coating of these bacteria, resulting in 12 treatments along with a control group (fermented sausages containing free bacteria, without cooking, and with nitrite). To assess their probiotic nature, samples were subjected to simulated gastrointestinal conditions, and the number of active bacteria upon reaching the large intestine was determined. Due to the similarity of Lactobacillus plantarum and Lactobacillus fermentum colonies on the culture medium, a method was used to determine the numbers and ratios of these two bacteria. Physicochemical, microbiological, and sensory tests were performed on the treatments. The highest protective effect on the bacteria during the drying and simulated gastrointestinal conditions was observed in treatments that used both hydroxypropyl methylcellulose and maltodextrin coatings at ratios of 3% and 3%, respectively. Moreover, the viability of Lactobacillus fermentum coated bacteria was lost immediately after the cooking process due to the applied heat. Treatments that had a higher number of live bacteria at the end of the simulated gastrointestinal conditions showed a significant difference compared to others (p<0.05), and the probiotic bacteria in them were encapsulated with 3% and 3%, 3% and 1.5%, and 1.5% and 3% of hydroxypropyl methylcellulose and maltodextrin, respectively. These treatments were used to investigate the physicochemical, microbiological, and sensory properties. The results of physicochemical and microbiological tests met the acceptable standards in Iran for this product. However, the physical properties of the original samples did not match those of the control sample (fermented sausage available in the market), and they had a significant difference at a confidence level of 95% (p<0.05). The obtained results indicate that by inoculating encapsulated probiotic bacteria with suitable and cost-effective coatings and applying cooking to sausages, it is possible to create a basis for the production of probiotic meat products in the market. However, further eva‎luation of these findings at an industrial scale is necessary to reach a final conclusion.

صبيحه سليمانيان زاد , ميلاد فتحي

نفيسه سلطاني زاده , اميرحسين مهدوي