Uso de maltodextrina no processo de encapsulação por spray drying do soro de leite derivado do queijo

Abstract

Whey is generated after coagulation for cheese making, and in general, its composition consists of water, lactose, glycerides, vitamins, enzymes and minerals. Due to the high biological demand for oxygen, fresh whey cannot be disposed of directly into the environment. Over the years, technologies have been studied with the aim of treating this effluent or transforming it into value-added raw material. Among the technologies used is the obtaining of whey powder through spray drying spray. The parameters used during drying are important for the process to be viable. Inlet air temperature, feed flow rate and the composition of the whey are the main parameters that can affect drying, as well as the glass transition temperature of the compounds present, and the adhesion of particles to the walls of the equipment. Encapsulation by atomization occurs in a similar way to drying in the equipment, however the compounds of interest are surrounded by encapsulating materials during the removal of water particles, resulting only in powdered capsules or microcapsules. Maltodextrin is widely used in the encapsulation process due to the favorable behavior of water solubility, emulsion property, good stability, and colorless solutions. Thus, the objective of the present work was to dry the whey using the spray dryer atomization technique using the whey in natura and with the encapsulating material maltodextrin in different concentrations, in order to verify possible improvements in the process and in the final yield of the whey powder that results in a product with high protein value and higher added value. In the drying of the fresh serum and the encapsulated serum, factorial design was applied with 3 central points, varying the drying temperature between 142 and 178 oC, the feed flow between 11 and 25 mL min-1, the serum concentration between 15 and 25 oBrix. In the drying of the encapsulated serum, the concentration of maltodextrin was varied between 10 and 20% (w/w) in the solution. The evaluated responses of the whey powder obtained were moisture, water activity, yield and protein concentration. Results showed that with the use of higher temperature, higher serum concentration and lower volumetric flow, lower values for moisture and water activity were achieved, and higher values for yield and protein concentration. The use of maltodextrin had a significant impact on the evaluated responses, reducing moisture and water activity compared to drying whey in natura. In addition, the encapsulated whey had a higher drying yield and a higher protein concentration. The variation in maltodextrin concentration did not influence the moisture and water activity of the whey powder. However, the yield and protein concentration reached higher values when higher concentrations of maltodextrin were used.