The effect of green tea and lemon essential oils on the physicochemical, microbial and sensory properties of oily cake

Todays, the tendency to use of natural preservatives to increase food security has expanded. The objective of this study was to use of lemon and green tea essential oils as antimicrobial and antioxidant compounds in oily cake. For this purpose, lemon and green tea essential oil in concentrates 0.1, 0.2, and 0.3% separately and in combination (0.2% green tea essential oil and 0.2% lime essential oil) were added to oily cake. Physico-chemical properties, anti-oxidant properties, microbial and sensory properties of the samples were evaluated, 2 hours after production and as well as at 7, 14, 21 and 28 days. The results showed that with increasing storage time, moisture content and pH in all treatments significantly decreased and acidity increased in all treatments. Comparison of the antioxidant and antimicrobial properties of oily cake containing green tea and lemon essential oils with control showed that the use of essential oils significantly prevented of the increase of peroxide and thiobarbituric index and the growth of mold and yeast during storage. The antioxidant properties of the treatments showed that the lowest levels of thiobarbituric and peroxide index were observed in a sample containing 0.3% green tea essential oil and combined treatment after 28 days of storage. Antimicrobial properties of the treatments indicated that there was no mold or yeast growing in the cake containing 0.2% and 0.3% lime essential oil and combined treatment after 28 days of storage. The results of sensory evaluation showed that the combined treatment had higher scores in terms of odor, color, taste, texture and overall acceptance and it was introduced as superior treatment.