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

Abstract

A response surface methodology approach 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 hours, at tempertures of 45, 55, and 65 °C and molasses concentrations were 40, 60, and 80% (w/w). The used responses variables were: dry matter, water loss, solid gain, and water activity. A Box et al. fractional factorial design (2 level-3 parameter with 15 runs (1 block) was used for design of the experiment. Dry matter, water loss, and solid gain 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: dry matter 50-60%, water loss 0.7-0.8, solid gain 0.08-0.09, and water activity 0.84-0.86. The optimum conditions generated were: treatment time of 4 hours, temperature of 60 °C, and sugar concentration of 66% (w/w).