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Athinoula
L. PETROU, Maria ROULIA and Konstantinos TAMPOURIS
ABSTRACT: Conservation and cooking of foods can be used by students and instructors to demonstrate a fundamental relation of chemical kinetics, the Arrhenius equation. By plotting the logarithms of available conservation and cooking times versus the corresponding inverse temperatures, apparent activation energies for both the deterioration and the cooking of foods of various compositions can be obtained. Such simple applications lead to meaningful results. Examples of deviation from the Arrhenius equation are given by plotting data (shelf-life of certain frozen food at various temperatures) given on the food package. A better fit is obtained by applying a second order polynomial regression to the data. Cooking time (lnt) vs. the inverse of temperature for five categories of foods is also examined and for each category there appears to be a common rate-determining step. Detailed results are presented for the meat category. The pedagogic aspects of the use of Arrhenius equation in the study of deterioration and of cooking of foods are also presented. [Chem. Educ. Res. Pract. Eur.: 2002, 3, 87-97] KEY WORDS: Chemical kinetics; deterioration of foods; cooking of foods; Arrhenius law (equation); deviation from the Arrhenius equation CORRESPONDENCE: Athinoula L. PETROU, Laboratory of Inorganic Chemistry, University of Athens, Panepistimioupolis, Athens, 15771, Greece; fax: +30107274782; e-mail: apetrou@chem.uoa.gr
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