COMPUTER‐AIDED PREDICTIONS OF EXTENT OF BROWNING IN DEHYDRATED CABBAGE

Abstract

SUMMARY– The feasibility and accuracy of prediction of extent of browning was studied on freeze‐dried cabbage stored in packages made of materials with different water‐vapor permeabilities. Kinetic data on the browning reaction were obtained for samples maintained at various constant‐moisture contents. In each case, browning increased linearly with time. An equation relating rate of browning to moisture content was chosen on the basis of minimum variance. The kinetic data were combined with mass transfer characteristics of the packages using assumptions discussed previously. The validity of the assumptions was tested and the magnitudes of needed corrections evaluated. Increase of moisture content and changes of the sorption capacity of the cabbage, caused by browning, proved to be the major factors requiring corrections. An iteration technique for the prediction of the browning, using a computer and a method for estimation of the variance of the predicted values, was devised. The standard deviation ranged from 2–10% for the low and high extent of browning, respectively. Most of the actual data obtained from package storage tests at 37°C and 61% RH were within 1 standard deviation of prediction.