Evaluation and Comparison of Lactic Strains Isolated from Traditional Iranian Dairy Products (Richal Shiri) with Armenian Dairy Products on Control of Food Spoilage Agents

Abstract Background & aim: Some bacterial metabolites isolated from fermentative products have antibacterial properties against food spoilage bacteria. The aim of this study was to evaluate the antibacterial properties of the isolated strains of traditional Armenian dairy products including cheese and traditional yogurts (Matson) and Richal  shiri as a traditional dairy products from Iran. Material and method: In the present experimental study, bacterial strains were isolated, and subsequently the antibacterial activity of supernatants of strains on several types of spoilages bacteria such as Salmonella  was assessed. In addition, isolated strains from Rachel shiri showed  a good  antibacterial properties against Salmonella typhimurium. Results: The isolated strains were significantly reduced food contamination and increased the shelf -life. Furthermore, isolated strains from Richal shiri showed a good antibacterial properties against Salmonella typhimurium Conclusion: LAB strains isolated with appropriate inhibition, fermented power as a natural preservative and pragmatic as new products may be used in the dairy industry

Investigation of Antibacterial Properties of Yeast Strains Isolated from Iranian Richal and Traditional Dairy Products in Armenia

Background & aim:The use of bio preservative or strains as sources are interesting for food bioprocessing technologist,&nbsp; &nbsp;and is one of the latest methods to increase the shelf life of food by the health authorities . The present study aimed to investigate the antibacterial activity of supernatants of yeasts isolated from Richal as a traditional dairy product and fermented dairy products in Armenia. Methods: In the present experimental study, the purified supernatant of 77 strains of Armenian yeast products and 12 strains from Iranian Richal were isolated. The purified supernatant were tested against three strains as food spoilages bacteria includes: B. subtilis 17-89, B. Thuringensis17-89, S.typhimuium G-38 , on 3media in 2 condition as aerobic and anaerobic. The inhibition zone of the supernatant were measured&nbsp;&nbsp; and reported as antibacterial activity. Data were analyzed using statistical tests. Result: A total of 89 strains of yeasts, three species of Rachel and 9 strains of Armenian products (13.5% percent) had demonstrated antibacterial activity. T86 strains of Armenian yeasts and FA1 (25) of Rachel had shown more ZOI and antibacterial activity on three media at both aerobic and anaerobic conditions. Comparing the mean of ZOI upon three corruption factors, Rachel strains were significantly different (p <0.05). The highest and lowest effect was observed on Bacillus subtilis effect and Salmonella typhimurium respectively. Conclusion: The results indicated that the yeast strains isolated in anaerobic and aerobic conditions on spoilage bacteria had antibacterial activity effect. Thus, it could be concluded that adding the yeast or its supernatant to food as a bio preservative, may introduce a operative product to the food industry