TY - JOUR ID - TI - Microbiological Effect of Lemongrass Cymbopogon Citratus and Spearmint Mentha Spicata Essential Oils as Preservatives and Flavor Additives in Yogurt AU - Ibrahim Jabber Abed AU - Alyaa Razooqi Hussein AU - Ghusoon Ali Abdulhasan AU - Anwar Neamah Dubaish PY - 2022 VL - 63 IS - 7 SP - 2839 EP - 2849 JO - Iraqi Journal of Science المجلة العراقية للعلوم SN - 00672904 23121637 AB - This study was designed to evaluate the antimicrobial effect of Cymbopogoncitratus and Mentha spicata essential oils, separately and mixed, against themicroorganisms in yogurt, as well as study the possibility of these essential oils(EO) as natural preservatives and flavors additives/enhancers in yogurt product.Yogurt samples were treated with lemongrass and spearmint EOin differentconcentrations (250, 500, 1000 ppm: 6250μg/50 ml yogurt, 12500 μg/50 ml yogurtand 25000 μg/50 ml yogurt respectively). The control and treated samples werepreserved both at room (25°C) and refrigerator (5°C) temperatures. In control, thecontamination was observed through 2 weeks at 25°C and for about one month at5°C. The samples treated with lemongrass and spearmint EOs (500pmm), thecontamination showed up late, after 45 and 30 days at 25°C respectively. While at5°C, the contamination appeared after 90 and 60 days respectively. The effect oflemongrass and spearmint EO, separately or mixed (synergistic effect), on thegrowth of fungi that was isolated from spoiled samples, was studied in differentconcentrations (125, 250, 500 ppm). Microbilogical examination was done in thecontrol and treated yogurt samples. There was a significant difference (P≤ 0.05)between microbial spoilage (coliform, yeast and fungi) count during differentperiods of incubation which decreased in the samples treated with essential oils ascompared with the control. The results of the percentage of growth inhibitionrevealed that lemongrass EO, around 80-100%, is the best in inhibiting the moldsand yeasts causing yogurt damage as compared to the use of spearmint EO whichwas 27-60%, and the synergistic effect of about 35-39%. The results of the toxicityassay of the maximum effect of EO in vivo proved their validity for consumptionwhen added both as preservative and flavor. The concentrations used for the dosageranged from 250 ppm to 5000 ppm.

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