Cheese Starter Production Using Lactic Acid Bacteria Isolated from Iranian Traditional Cheeses

Introduction: Lactic acid bacteria (LAB), as the main dairy starters, play an essential role in the production of volatile compounds such as proteolytic and lipolytic enzymes involved in cheese processing, suppression of pathogenic microorganisms, formation of curdling tissue, and creation of a fresh acidic flavor.Materials and Methods: In this study, the LABs were isolated from fourteen samples of traditional cheeses in different part of Iran. The isolates with the highest cheese production capacities were selected and subsequently various factors including pH and temperature were evaluated on their activity. Besides, the viability of strains, which were used to produce traditional cheeses, under microencapsulation and gastric simulation conditions was also investigated. Finally, the best LAB strains (BCC۷ and BCC۱۰), with desirable characteristics for cheese production, were molecularly identified by using the ۱۶srDNA test.Results: This study showed that the survival rate of BCC۷ and BCC۱۰ isolates microencapsulated with sodium alginate/chitosan were higher than free cells in the storage condition of -۸۰ °C after six weeks by ۲۳.۵۰% and ۲۰.۷۸%, respectively. Moreover, the quantification of the activity of BCC۷ and BCC۱۰ strains at a temperature of ۴ °C yielded ۱۱ ۱۰۷ CFU/ml and ۹ ۱۰۷ CFU/ml, respectively; exhibiting a greater activity than that observed at a temperature of ۲۸ °C. Furthermore, the preservation of their morphological and biochemical properties was observed.Discussion and Conclusion: The present study determined the sequences of the most efficient lactic acid strains, and subsequent analyses indicated that the BCC۷ and BCC۱۰ strains isolated from native cheese samples, were corresponded to Enterococcus faecium strains SKL-۴ and ۲۷۶-۱۸, respectively. Therefore, these two strains are good candidate to introduce to the market as high-quality starters for dairy industries.

Cheese Starter Production Using Lactic Acid Bacteria Isolated from Iranian Traditional Cheeses Keywords:

Cheese starter , Enterococcus faecium , Lactic acid bacteria , Proteolytic activity , viability