A New Probiotic Cheddar Cheese with High ACE-Inhibitory Activity and g-Aminobutyric Acid Content Produced with Koumiss-Derived Lactobacillus casei Zhang

Cheddar cheese has been manufactured with Lactobacillus casei Zhang as the dairy starter adjunct. L. casei Zhang had previously been isolated from koumiss collected from Xilin Guole in Inner Mongolia and characterized in detail with regard to their probiotic potential. The addition of L. casei Zhang to Cheddar cheese had no adverse effects on sensory criteria. The cheese made with 0.1, 1 and 2 % of the probiotic strain L. casei Zhang adjuncts contained high levels of the Lactobacillus after 6 months of ripening with final counts of 9.6·10, 7.7·10 and 1.02·10 CFU/g, respectively. In the ripe control cheese, without the addition of probiotic strain L. casei Zhang, the number of Lactobacillus reached 5.7·10 CFU/g. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) analysis was used to distinguish the added L. casei Zhang from the natural flora of the cheese and to determine whether L. casei Zhang grew in the cheese. ACE-inhibitory activity and g-aminobutyric acid (GABA) concentrations in the cheese were measured. Compared with control cheese, experimental cheese with 0.1, 1 and 2 % of probiotic strain L. casei Zhang revealed some increase in ACE-inhibitory activity and GABA mass fraction. In the present study, the production of both ACE-inhibitory activity and GABA in the probiotic cheese with the L. casei Zhang adjunct isolated from koumiss has been found for the first time. The results suggest that cheese with the probiotic strain L. casei Zhang showed good potential for application in the management of hypertension.