Otimização do processo de produção de doce de leite com substituição de parte do leite por soro de queijo in natura

Abstract

The objective of this work was to develop a mathematical model to minimize the cost of "doce de leite" production, replacing the milk for the cheese whey in natura, and through mathematical modeling to determine the maximum amount of cheese whey in natura which can be used in the "doce de leite" production, allowing the final product remains with the approval of the consumer and the law for the product. The mathematical model was developed using the balances of mass, energy and component of the "doce de leite" production process. The objective function of the problem was developed through the summation of costs multiplied to quantities of raw materials. It was also defined the variables and the parameters for the problem. Three cases were studied. In the first case, it was studied the "doce de leite" production with cow's milk and cheese whey. In the second case, was studied the "doce de leite" production with goat's milk and cheese whey. In the third case, was studied the "doce de leite" production with cow's milk and goat's milk. In all cases were developed a standard "doce de leite" ("doce de leite" with only cow's milk and doce de leite with only goat's milk) allowing the comparison of costs. The results obtained from the models developed shown that the best completion percentage for both the mixture of cow's milk and cheese whey in natura, in the production of "doce de leite" was 73,3% cow's milk and 26,7% of cheese whey. The production of "doce de leite" with goat milk and cheese whey can happen with 50% of goat milk and 50% of cheese whey. The mix of goat milk and cow milk can involve in earning maximization of final product, which means, an increase in the process performance. In front of the results obtained, one can conclude that the developed model for the "doce de leite" with cow's milk and cheese whey is a representative model, because the same way that the results were obtained in laboratories tests, it minimized the cost of production, finding a ideal percentages for cow's milk and cheese whey, besides its application in other cases with different milks. The models developed for "doce de leite" with goat's milk and cheese whey in natura and the "doce de leite" with cow's milk and goat's milk, need to be taken in practice to the model can be valided. The optimazer GAMS was an efficient software in the resolution of the models, also showing a quickly resolution for this type of problem.