Effect of Some Essential Oils on the Quality of UF-Soft Cheese During Storage

The present study aimed to evaluate the chemical composition, antioxidant activity, antimicrobial properties and the minimum inhibitory concentrations (MICs) of three essential oils extracted from cumin, rosemary and thyme and their mixture and their effect on physicochemical, microbial, rheological and sensorial attributes of ultrafiltrated (UF)-soft cheese. UF-soft cheese was prepared from UF milk retentate with adding 0.1% of these essential oils. The results revealed that the different essential oils had remarkable antimicrobial effect on the growth of Escherichia coli (E. coli), Salmonella typhimurium (S. typhimurium), Staphylococcus aureus (S. aureus), Bacillus subtilis (B. subtilis), Bacillus cereus (B. cereus), and Aspergillus niger (A. niger). Among essential oils, thyme oil had the highest antioxidantactivity and antimicrobial effect. Addition of essential oils appeared to affect cheese pH and total volatile fatty acid content during storage period, while total solids and fat contents were slightly affected. Addition of essential oils to retentate resulted in an increment in antioxidant activity and decreased the total bacterial count compared with the control cheese. Sensory evaluation revealed that UF-soft cheese containing essential oils remained acceptable even at the end of storage period. Adding cumin essential oil to UF-soft cheese gained the highest scores for the sensorial attributes.The results concluded that a concentration of 0.1% of essential oils extracted from cumin, rosemary or thyme or their mixture can be used to extend the shelf life of UF-soft cheese for up to 28 days. These essential oils could be successfully used as natural and safe additives in production of UF- soft cheese.