Estudio cinético y de superficie de respuesta para ia rehidratación de zanahorias (Daucus carota) liofilizadas

Abstract

In this work the effect of temperature on the kinetics, the diffusion coefficient sand the addition of citric acid and sodium chloride on the rehydration of frozen-dried carrots (Daucus carota) have been studied. The model response surface was 4 factors with 3 central points. For 70 and 93°C, no significant differences (α=0.05) for the kinetic constant with mean of 0.42min-1. Important differences were found between diffusion coefficients, from 6.1 to 3.18 × 10-9 m2/s for 70 y 93°C. The variables with higher influence on rehydration were the content of citric acid, citric acid concentration and temperature, at the studied levels. The best condition for rehydration of carrot frozen-dried was obtained for 0.636 g/100ml acid concentration with 7 kg of water/kg dry solid, using the surface model. The mean value was 6.65 kg of water/kg dry solid.