EFFECT OF CERTAIN ADDITIVES ON SORBATE STABILITY

The effect of several additives on sorbate stability was studied in aq ueous model systems of 0.91 water activity at pH 5.0. The rate constan ts of sorbic acid destruction could be described by first order kineti cs. Non-enzymatic browning reactions exhibited zero order kinetics and were greatly influenced by sorbic acid destruction and in all systems a correlation between the natural logarithm of sorbates retention and the increase in the absorbance at 420 nm was found. Polyphosphates an d propylgallate protected sorbic acid from destruction. Ascorbic acid showed a dual behavior: in the absence of sodium nitrite, it exhibited a pro-oxidant effect. When nitrite was present, ascorbic acid behaved as a protector. In general, sucrose did not influence the rate of sor bic acid destruction and the effect of sodium nitrite was diverse. In all cases, inclusion of glycine enhanced sorbic acid destruction and b rowning development. Copyright (C) 1996 Published by Elsevier Science Ltd on behalf of the Canadian Institute of Food Science and Technology