MATHEMATICAL-MODEL FOR COMPUTER-SIMULATION OF MOISTURE TRANSFER IN MULTIPLE PACKAGE SYSTEMS

A mathematical model was developed for moisture transfer in multiple package systems wherein different food products or components are packed in individual primary packages and further unitized in a secondary package. The Guggenheim-Anderson-de Beer (GAB) equation for moisture sorption isotherm was differentiated with respect to time and incorporated in the generalized moisture transport equation for the multiple package system resulting in a system of simultaneous first order differential equations relating changes in water activities of the products to storage time. These equations are solved by the Runge-Kutta method, and the corresponding moisture changes in the products are obtained by using the original isotherm equations. The computer programme developed on the basis of the model was used to simulate moisture changes in a 2-component multiple package system of doughnut mb. The predictions were in close agreement with the experimental values.