An assessment of Cuminum cyminum (Boiss) essential oil, NaCl, bile salts and their combinations in probiotic yogurt

Abstract

This article is prepared to investigate the impacts of Cuminum cyminum essential oil (CEO), NaCl, bile salts, and their combinations on the viability of Lactobacillus casei in probiotic yogurt. The water distillation method was used to extract the CEO, and GC/MS was used to determine its constituents. Then, the CEO's antibacterial activity, together with NaCl and bile salts, was investigated via the microdilution technique by determining the minimum inhibitory concentration (MIC) against L. casei. Further, the stress effects of 50% MIC on CEO, NaCl, and bile salts were examined by comparing the stress treatments with the control in terms of the L. casei population, pH, acidity, and syneresis percentage in probiotic yogurt during storage in the refrigerator for 28 days. According to the results, the L. casei population and pH decreased in all the treatments during the storage time, such that the intensity of the decrease in the control and CEO treatments was lesser than in other stress treatments (P<0.05). The acidity and percentage of syneresis during the storage time increased for all the treatments, with the increase being less in control and CEO than in the other stress treatments (P<0.05). The control and CEO treatments scored the highest in the sensory evaluation (P<0.05). Applying stresses below the MIC resulted in the survival of L. casei in the recommended amount (105-106 CFU mL-1) in the probiotic yogurt until the end of 28 days.