Energy-saving new drying technology: Interval starting accessibility drying (ISAD) used to intensify dehydrofreezing efficiency

Abstract

The aim of this study is to develop a new emerging technique to solve the main problem of conventional drying which is energy consumption. Interval Starting Accessibility Drying (ISAD) is based on subjecting food samples to an instantaneous action of hot air close to the starting accessibility time, during very short time followed by tempering periods (< 5 min). Quince samples have been submitted to ISAD with a temperature of 40 °C and different air flow velocities (2; 3.5; and 5 m/s), with 15 s of active time and tempering periods between 1 and 5 min. The impact of ISAD compared to conventional drying has been significant in terms of effective drying time and energy consumption. Hence, ISAD treatment significantly reduces the effective drying time by about 89% to reach the same final water content for conventionally dried quince samples. These results have promoting technological impact: a significant gain of energy is gotten by inserting short tempering periods. Consequently, ISAD can be considered as a relevant way for intensifying the internal resistance to water transfer during pre-drying process of fruits.