Construction of a design space for goat milk powder production using moisture sorption isotherms

摘要

Industrialization of goat milk is critical to meet increasing demand. For process optimization and proper preservation of the product, information given by sorption isotherms can be fundamental. Therefore, the objective of this work was to determine the sorption isotherms of the goat milk powder and use that information to build a design space for the spray drying process. By fitting different mathematical models (GAB, Cavalcanti Mata, Thompson, and Oswin) to the experimental data, thermodynamic data was also determined as a function of equilibrium water content. The results allowed the construction of a phase diagram based on glass transition temperatures, and moisture content of 2.40% at the monolayer which provided a reference for the range of stability of water activity and a target for the final moisture content. By determination of net isosteric heat, it is clear that the values of energy for drying goat milk beyond the monolayer moisture content is much higher than for pure water vaporization enthalpy. Finally, using the fitted GAB model it was possible to construct a design space for the spray drying process of goat milk, and optimal spray drying parameters were determined. Practical Applications The construction of a production design space is critical for process scale-up. On our work, we developed a new method to build such design space using the information provided by the moisture sorption isotherm and a fundamental model for the spray drying process. Therefore, a theoretical design space can be built with minimal resources which can be very useful for new products.