MODELING OF REHYDRATION KINETICS OF GREEN BELL PEPPERS

Abstract

The water absorption characteristics of dried green bell peppers were studied at hydration temperatures at 25, 50 and 75C. Prior to drying at 65C, green bell peppers were pretreated with ethyl oleate (AEEO) and citric acid (CITRIC) solutions. Initial rehydration rates increased with rehydration temperature for all samples and were highest for the AEEO pretreated samples. At all rehydration temperatures, the equilibrium moisture contents were highest for the pretreated with AEEO solution. The moisture diffusivity (D) was determined by using Fick's second law. The values of D varied from 16.8 to 32x10(-8), 9.16 to 16.7x10(-8) and 9.73 to 19.9x10(-8)m(2)/s for AEEO, CITRIC and CONTROL samples, respectively, over the temperature range investigated. PRACTICAL APPLICATIONSThe rehydration characteristics, which indicate the physical and chemical changes during drying process of a dried product, are used as a quality index. Therefore, drying conditions should be optimized to obtain the dried product with good rehydration characteristics. In the present manuscript, studies were conducted to probe the kinetics of rehydration of dried green bell peppers. The effect of pretreatment of green bell pepper with chemicals (ethyl oleate and citric acid) and rehydration temperature on the rehydration kinetics was studied. Important rehydration kinetic parameters were evaluated, which helped in successful modeling of the kinetics.