Influence of encapsulating matrices on the rheological behavior of fermented whey permeate suspensions

Abstract

This work aimed to characterize the rheological behavior of whey permeate suspensions, used in the spray dryer microencapsulation process. Whey permeate fermented by Propionibacterium freudenreichii PS-1 was used, the wall materials used were maltodextrin (DE-20) and modified starch in a ratio of 1: 4 of active and encapsulant, in six different treatments. The analysis of rheological behavior and apparent viscosity were performed with a rotational rheometer of concentric cylinders, and solids soluble by refractometry. The results showed that the apparent viscosity of the samples with the highest amounts of starch presented the highest values, inferring that this encapsulating material affects the apparent viscosity of the analyzed suspensions more than the maldodextrin, similar results were obtained with the soluble solids index. For the Newton model it was possible to notice that all treatments showed values ​​greater than 1, characterized as dilating suspensions and for the Ostwald-de-Waele model, all treatments presented pseudoplastic characteristics.