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G. KALETUNC, Ohio State University

Food materials reveal a number of thermally induced transitions as a result of heating or cooling. Because these transitions involve changes in heat capacity as a function of temperature, temperature scanning calorimetry provides a useful tool for study of these processes. The use of differential scanning calorimetry (DSC) for measurement of physical properties of pre- and post-processed food materials, food ingredients, and additives has increased rapidly over the last 20 years. The utility of DSC to measure the physical properties of food materials as a function of conditions simulating food processing and storage increased its applications both in academia and in industry. The broad range of DSC applications and the vast number of materials present the challenge of standardization of sampling, DSC procedures and, most specifically, the analysis and reporting of measured data. The analysis of DSC data frequently complicated by multiple overlapping transitions and kinetically controlled events which occur in food materials. Procedures to collect reliable, reproducible data, and comparison of data analysis procedures will be presented. Factors influencing the quality of measured data will be discussed. The importance of standardized reporting of DSC data in order to provide reproducible values for thermal properties among various laboratories will be emphasized. Ongoing efforts by a National Research Committee (NC-136) to standardize the glass transitions measurements will be reported.