Unidade produtora de leite de cabra in natura e de leite em pó: design, simulação e otimização do processo.

Abstract

Goat milk is a very nutritionally rich food, generating numerous benefits for human health, especially for people who are allergic to cow's milk. The Brazilian northeast has the largest herd in the country, and Paraíba is one of the states that most produces such food. However, the economic potential of this product is little explored, with a large part of the production destined for family subsistence or for sale in natura on a small scale. Milk dehydration is an excellent option for large-scale commercialization. The objective of this work is to study the milk drying process, in order to optimize it, through the drying parameters. Fifteen drying experiments were carried out, modifying the concentration (20, 30 and 40%), the atomizer rotation speed (300, 400 and 500 hz) and the inlet temperature (170, 190 and 210°C). The physicochemical characterization of the powders obtained in these treatments was carried out (pH, lactic acid acidity, humidity, ash, fat, defatted dry extract, density, proteins, lactose, cryoscopy and salts). Physical analyzes were also performed (angle of repose, wettability, solubility, apparent and compacted density, porosity, scanning electron microscopy and color analysis). It was observed that all analyses, except salt content and real density, had at least one statistically significant parameter, confirming the importance of defining these parameters in the process. The quality of the product obtained, in general, was quite satisfactory, since practically all analyzes were able to achieve results within the standard established by the standard and/or literature, in all treatments. In general, the treatments that showed the best results were 13 (190°C/400Hz/30%), central point, which had good results in almost all analyzes and had an excellent performance, and 9 (190°C/300Hz /20%), which, although it also achieved excellent results in the analyses, had a lower yield. A rheological study of the concentrations used in drying was also carried out and it was observed that the higher the concentration of milk, the greater the need for a shear stress to start the flow of the same, requiring more energy for pumping the product. Increasing the concentration causes the milk to vary from Newtonian to non-Newtonian with dilating behavior. It was also observed that the Bingham and Ostwald-waele models were the ones that obtained the most satisfactory results. Another objective of this work was the design of the layout of the powdered milk factory, to be installed in the semi-arid region of Paraíba. Using the SLP and Gerchet method, diagrams were generated (interrelation of activities, relationship of areas, relationship of space) to facilitate the creation of options for physical arrangements. It was also necessary to know the entire production process of powdered milk, which could be summarized in the process chart. Another point discussed here was the creation of the HACCP plan for the future factory. It was identified that such a process has some critical points such as the receipt of milk, pasteurization and drying of the product, requiring monitoring during the process.