Kinetics of growth and inhibition of Listeria monocytogenes in the presence of antioxidant food additives

Listeria monocytogenes strain Scott A in Tryptose Broth was treated with 100-300 ppm butylated hydroxyanisole (BHA), 300-700 ppm butylated hydroxytoluene (BHT) and 10-30 ppm tertiary butylhydroquinone (TBHQ). Resulting growth curves were fitted using the logistic model, and growth parameters [lag period (LP), generation time (GT), and maximum growth (MG)] were calculated. BHA and BHT inhibited Listeria monocytogenes by increasing LP and GT and decreasing MG. Extent of inhibition was concentration-dependent for cultures with BHA, but not with BHT. TBHQ at 10-30 ppm increased LP but did not affect other parameters. LP increased exponentially with increased BHA or TBHQ in Listeria culture. Concentrations of additive required to increase LP by one order of magnitude were 240 ppm for BHA and 26 ppm for TBHQ