Antimicrobial Activity of Dried Spearmint and Its Extracts for Use as White Cheese Preservatives

Spearmint which is common herb in the Mediterranean region was evaluated (dried or extracts) as inhibitor factor against the growth of twelve microbial strains belonging to bacteria, yeasts and moulds using filter paper disc agar diffusion technique. Water extract had no inhibitory effect on all strains under study. A moderate activity of ethanolic extract against Gram positive bacteria (Bacillus cereus and Staphylococcus aureus) was observed. Essential oil was the strongest antimicrobial inhibitor; therefore, its antifungal activity and minimum inhibitory concentration (MIC) were examined. To evaluate the antimicrobial activity of spearmint, white cheeses were prepared using different concentrations of dried spearmint and its essential oil. Such an oil showed significant reduction in the counts of total bacteria, proteolytic and psychrotrophic bacteria as compared with control samples. Moulds and yeasts were totally inhibited by using the essential oil.