Prediction of Time Correction Factor for Come‐up Heating of Packaged Liquid Food

摘要

ABSTRACTAll physical properties and operational conditions which have an influence on the come‐up heating correction factor (Cf), of packaged liquid food were examined and subjected to a dimensional analysis. Five dimensionless groups which uniquely define the correction factor were obtained. The influence of the parameters on the values of Cfwas studied through application of a central composite experimental design and a nonlinear regression analysis, from which a regression equation for the prediction of the correction factor was obtained. It was found that the Cfvalues may vary between +0.86 to −0.37, having an average value of 0.31. Mathematical examination of the regression equation obtained indicates that a dimensionless group which is related to the temperature history of the heating medium during the come‐up phase is the most important in determining the value of Cf, while another which is a function of the processing time has a negligible influence on this parameter. The reliability of our regression equation was verified experimentally with distilled water, 0.1 locust bean gum and tomato soup packed in cans 211 × 300 and 307 × 409. Good agreement between experimental and predicted Cfvalues was o