Study and optimization of osmotic dehydration of cherry tomatoes in complex solution by response surface methodology and desirability approach

The osmotic dehydration of cherry tomatoes in complex solution of salt and sugar was studied by using the response surface methodology while the approach of desirability was applied to define the best operative conditions taking into account contemporaneously several quality parameters. Water activity, moisture content, consistency and red index (a*) were the only parameters which showed significant changes as a function of the independent variables. The changes of these attributes were well modeled obtaining in all cases a correlation coefficients greater than 0.94; treatment time and the mass fraction of sucrose were the most important variables for reducing water activity and moisture content while for consistency and color, the mass fractions of sucrose and sodium chloride were the most important processing variables. Desirability approach allowed defining the best operative conditions; specifically, when the overall quality of osmotized cherry tomatoes was considered as equilibrium of values of aw, consistency and red index, a maximum desirability of 0.736 could be obtained by using mass fractions of sucrose and NaCl respectively of 55.62 and 2.45% and a treatment time of 22 h.