Suppressing E. coli activation in probiotic yogurt during fermentation by supplementing bitter melon (Momordica charantia L.) ethanol extract

Abstract

In this study, the survival of Escherichia coli (ATCC (R) 25922T) in probiotic yogurt supplemented with or without Momordica charantia L. ethanol extract (MCE) during the fermentation period (0-300 minutes) was analysed for various inoculation levels (102; 104 and 106 log CFU/mL). So, the measured E. coli number was modelled as a function of fermentation time and the number of inoculated E. coli. The polynomials models were calculated separately for the probiotic yogurts with and without MCE added. Then, E. coli numbers predicted by the models were analysed using various scientific methods (Transforming predicted E. coli numbers into images, image processing, and hierarchical classification algorithms). The analysis results showed that the E. coli inactivation at between 2.44-3.47 log CFU/mL depending on inoculation levels was determined at the end of fermentation for probiotic yogurts supplemented with MCE. However, the determined inactivation for probiotic yogurts without MCE was between 1.84-2.99 log CFU/mL.