Finite Element Simulation of Shelf Life Prediction of Moisture-Sensitive Crackers in Permeable Packaging under Different Storage Conditions

Abstract

A finite element method (FEM) approach using COMSOL Multiphysics software was presented to solve unsteady-state moisture diffusion differential equations and predict the shelf life of crackers based on critical moisture content obtained by sensory evaluation. The crackers' moisture contents were given as a function of storage time, environment conditions (temperature and relative humidity) and the package materials. Classical Oswin model was used to fit the moisture sorption data at four different temperatures. Effective moisture diffusivity of crackers as a function of moisture content and temperature were investigated. In addition, the relationship of moisture permeability coefficient and temperature of two selected packaging films, low-density polyethylene (LDPE) and cast polypropylene (CPP) film, was determined based on Arrhenius equation. The crackers were packaged in LDPE and CPP packaging pouches, and stored at four different conditions to simulate actual storage conditions and determine the shelf life experimentally. There was a good agreement between experimental results and finite element predictions for moisture-sensitive crackers subjected to different storage and packaging conditions. Practical Applications This paper describes the shelf life prediction of crackers using a simulation model based on unsteady-state Fickian diffusion of moisture through the food. The temperature effect on the moisture sorption, moisture diffusivity of foods and the moisture permeability coefficient of packaging films are considered. The food product's moisture content was simulated using COMSOL Multiphysics as a function of storage time under different storage conditions and packaging film. The finite element simulation provides a powerful support tool for shelf life estimation and packaging development.