Effect of Rosmarinus officinalis essential oil on Lactobacillus count and amount of Histamine during ripening period in traditional Lighvan cheese

Histamine poisoning is one of the main concerns in traditional cheese health and its most important producers are decarboxylating bacterial strains which act during cheese ripening period. The aim of this study was to determine the effect of Rosmarinus officinalis essential oil (EO) on Lactobacilli count and Histamine amount in Lighvan cheese using HPLC method. The Chemical composition of EO was detected using GC/MS. Cheese samples containing 0, 125 and 250 ppm of Rosemary EO were prepared. Lactobacillus count and Histamine amount of samples were measured on days 0, 30, 90 and 150 of the ripening period. Alfa pinene (11.1%), Camphore (10.2%) and Limonene (5.9%) were detected as three main components of rosemary EO. Lactobacillus count on the understudied days in all EO-treated groups (125 and 250 ppm) was significantly (p<0.05) lower compared to the control group during ripening period and Histamine amount in control, 125 and 200 ppm groups were 190, 170 and 51.04 mg/kg respectively. Overall it could be concluded that addition of 125 and 250 ppm of rosemary EO could act as a natural preservative in traditional Lighvan cheese.