EFFECT OF POTASSIUM SORBATE AND SODIUM BISULFITE ON THERMAL INACTIVATION OF SACCHAROMYCES CEREVISIAE IN MEDIA OF LOWERED WATER ACTIVITY

The presence of 100 ppm of potassium sorbate caused significant increases in the rate of inactivation of S. cerevisiae suspended in distilled water at pH adjusted to 3.0 and heated at 50.degree. C. The addition of sugars (glucose or sucrose) to water activity 0.95 decreased the lethal effects of sorbate mainly when glucose was the sugar added to the heating medium. It was found, however, that a mixture of 50 ppm of sorbate and 50 ppm of sulfur dioxide acted synergistically with heat to rapidly inactivate the yeast during heating even in the presence of glucose.