Combined Effect of Water Activity and pH on the Inhibition of Escherichia coli by Nisin

摘要

The Doehlert design and surface response methodology were used to study the influence of pH and water activity (a_w) on Escherichia coli inhibition by nisin. Combining stress factors at levels where they are not inhibitory by themselves. a reduction of E. coli survival fraction can be achieved with lower nisin doses than in a single nisin treatment. For all the pH values assayed, a synergistic effect of a_w and nisin concentration was detected, and the isoresponse lines showed the existence of an area of maximum inhibition.