Abstract: A process for preparing a dish of cooked foodstuff product, which process comprises the steps of (a) measuring the pH of the product, (b) determining the oxidoreduction potential E of the product, (c) calculating the rH.sub.2 value of the product using Nernst formula: rH.sub.2 =2pH+33.33E, (d) determining whether the cooked dish is reductive, neutral or oxidative where the pH and rH.sub.2 have been determined by reference to the position of the cooked dish relative to a curve rH.sub.2 =f(pH) of the drawing, (e) determining a pasteurization value from the results of step (d) to determine a cooking temperature range that is below a 100.degree. C. for the product by varying at least one of the pH of the product while maintaining the pH above 4.