1. Identify the time for C. botulinum to produce toxins in pasteurized process cheese products. </P>
2. Confirm analytical values of 80 different formulations </P>
3. Develop a predictive model to identify time for toxin production based on 7 factors identified in proposal.
Multiple research projects have confirmed that sodium-based salts are key control factors that inhibit pathogenic sporeforming microorganisms in process cheese products. The Tanaka model or FRI model have become the standard by which FDA and many manufacturers measure process cheese product safety. This model defines safe process cheese spread formulations using parameters of moisture, total salts, and pH to inhibit growth and toxin production by C. botulinum. Although this model is very reliable in predicting safety under the conditions in which it was run, the effects of additional factors har not considered. </P>This study will expand the C. botulinum food safety curves to reduced-sodium process cheese products and will consider the interactive effect of moisture, pH, potassium-based replacements for sodium chloride and phosphate emulsifier, fat and sorbic acid. Eighty (80) formulations of process cheese (based on a central composite design) will be prepared by Kraft Foods and transported to UW-Madison for inoculation with C. botulinum spores. Data from toxicity testing and proximate analyses will be used to develop a model to predict safety of products stored out of refrigeration.