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

Abstract

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 antioxidant activity 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.

Using Rosemary Essential Oil as a Potential Natural Preservative during Stirred-like Yogurt Making

“…The enhancement effect of REO addition on sensory properties in our study matched the findings reported by El-Kholy et al, as they showed that adding REO to ultra-filtrated soft cheese samples improved sensory characteristics, while the control samples had lower scores [34]. According to other findings, adding 0.14 g/L of REO to yogurt samples resulted in the best flavor, taste, and texture, whereas increasing the previous concentration resulted in the worst flavor, taste, and texture [15].…”

“…The decline in protein content in our study after 8 days of storage could be attributed to proteolytic activity by added microorganisms (76). Our findings are consistent with the results of El-Kholy et al and Thabet et al [34,82].…”

“…Results obtained by El-Kholy et al, who found that the protein content decreased in cheese samples after the addition of REO (from 17.18% in control samples to 16.91% in cheese made with REO) [34], were in agreement with our study. The decline in protein content in our study after 8 days of storage could be attributed to proteolytic activity by added microorganisms (76).…”

“…El-Kholy et al studied the antimicrobial activity of REO against six microorganisms and found that the MIC of REO was 0.5%, with inhibition zones ranging from 7 to 13 mm in diameter [ 34 ]. A previous study by Jardak et al found that REO has antibacterial activity against Staphylococcus aureus (1.25–2.50 µmL) [ 35 ].…”

The Future Trend Natural Preservatives in the Food System: Essential Oils

“…According to the data, preventing the growth of E. coli, S. typhi, S. aureus, B. subtilis, B. cereus and A. niger on cheese. Thus, essential oils supplied an extension of shelf life and improvement for consumer perception [28]. Singh, Kapoor, and Singh (2011) established that the spoilage caused by bacteria was well controlled when anise EO and its oleoresin were added with yogurt at varying concentrations (0.1-1.0 g/L) [29].…”