HEAT-RESISTANCE OF BACILLUS-SUBTILIS AND BACILLUS-COAGULANS - EFFECT OF SPORULATION TEMPERATURE IN FOODS WITH VARIOUS ACIDULANTS

The influence of the sporulation temperature (35 and 52 degrees C) on the effect of different acidulants on the heat resistance of Bacillus subtilis and Bacillus coagulans in homogenized tomato and asparagus at pH 4 was investigated. Several acidulants (hydrochloric, citric, acet ic, lactic, and malic acids and glucono-delta-lactone) currently used by the canning industry to lower the pH of some vegetables before proc essing were studied, The sporulation temperature determined the respon se of these microorganisms to the type of acidulant. While the heat re sistance of spores sporulated at 35 degrees C was the same at all heat ing temperatures tried, regardless the type of acidulant, that of spor es sporulated at 52 degrees C was two- to fivefold lower when lactic o r acetic acids were used. This decrease in heat resistance was the sam e at every temperature over the whole range of heating temperatures te sted. The z values obtained with each microorganism were the same for a given heating menstruum, regardless the type of acidulant used.