Storage stability of carrot chips

Abstract

Water activity combined with the glass transition temperature can be used to predict the shelf life of foods. Water sorption isotherms and glass transition as a function of moisture content were determined for carrot chips after vacuum frying. The GAB model was fitted to the measured sorption data while the Gordon Taylor equation was used to model the water plasticization effect. The critical moisture content and the critical water activity at which the glass transition occurs were obtained at selected storage temperatures. The changes in moisture content, fat content, water activity, breaking force, β-carotene content, ascorbic acid, and acid value of vacuum-fried carrot chip at selected storage temperatures (0, 10, 25°C) during a 6-month storage period were investigated. The estimated shelf life of carrot chip, defined by the degradation time of the acid value at different storage conditions, was determined.