Convective drying optimization of carrots in two-stages

Abstract

The carrots represent the main vegetable source of carotenoid provitamin A, especially alfa and beta-caroteno, that can be transformed in vitamin A in the animal organism. Studies about carotenes retention during drying of carrots are important since this vegetable is largely consumed. Drying can extent the shelf life and improve shipping and commercialization of this products. However, the drying temperature can negatively affect the physical and nutritional foods properties, making difficult the control of this process. This project aim investigates the carrots drying in two stages, using a higher initial temperature and subsequent temperature decrease. Temperature and drying time will be optimized based on maximum carotenes and color retention and minimum energy consumption. Experimental design methodology will be used combined with the analysis of the response surface. We wish to reproduce, in an approximate way, the operating conditions of a conveyor dryer with drying temperature controlled in different sections of the equipment, to determine parameters that represent economy and improvement of the dehydrated food quality. Drying kinetics in two stages will be determined for the best process conditions previously selected.