Influences of vanillin and licorice root extract supplementations on the decimal reduction times of Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm

This study determined the influences of supplementing different combinations of vanillin (0-500 ppm) and licorice root extract (LRE, 0-420 ppm) on the mild heat (55 °C) decimal reduction times (D55-values) of a cocktail of Escherichia coli O157:H7 in young coconut liquid endosperm. The maximum level of supplementation per additive tested was previously established not to result in the lowering of general consumer acceptability of the liquid endosperm. The D55-values ranged from 15.08 to 31.40 min. The influences of both additives on the D55-value fitted significantly into a 2-factor, interaction model with only the joint effect of the additives having significant effect on D55. The combined efficacies of the additives were most significant at concentrations above 250 ppm vanillin and 210 ppm LRE. The results obtained may be used in the establishment of mild heat pasteurization processes for supplemented young coconut liquid endosperm, for better control of quality and safety.