Optimization of operating conditions of a cooling tunnel for production of hard candies

► Development of a mathematical model to determine the optimal operating conditions of the cooling tunnel. ► Three objectives functions (OFs) based on the product quality are proposed and analyzed. ► Minimization of the temperature difference inside hard candies is required to assure quality. ► OF3 is the best objective function to be used. ► Minimization of OF3 (va/TaT) shows the best performance in the optimization problem.