Optimization of the osmotic dehydration of carrot cubes in sugar beet molasses

Abstract

A Response Surface Methodology approach (RSM) was used to determine optimum conditions for the osmotic dehydration of carrot cubes in sugar beet molasses. Treatment times were set to 1, 3 and 5 h, at temperatures of 45, 55 and 65?C and molasses concentrations were 40, 60 and 80% (w/w). The used responses variables were: final dry matter content (DM), water loss (WL), solid gain (Sg), and water activity (aw). A Box and Behnken?s fractional factorial design (2 level-3 parameter) with 15 runs (1 block) was used for design of the experiment. DM, WL, Sg were significantly affected by all process variables (at 90-95% confidence level). The optimum conditions were determined by superimposing the contour plots, with the following response limiting values: DM 50-60%, WL 0.7- 0.8, Sg 0.08-0.09, and aw 0.84-0.86. The optimum conditions generated were: treatment time of 4h, temperature of 60?C, sugar concentration of 66% (w/w).