Obtenção da levedura Saccharomyces cerevisiae em pó pelo método da secagem em camada de espuma

Abstract

The yeast Saccharomyces cerevisiae is an importantraw material in the food and beverageindustry, generating large amounts of residual biomass. In order to add value to this residue, this study proposes the use of the foam layer drying technique to produce yeast powder from biomass discarded from the fermentation of cachaça. This technique employs thickening and stabilizing agents to form a stable foam that resists dehydration under increasing temperature. The study also aims to evaluate the physicochemical characteristics of the yeast powder obtained by this technique. The foam production followed a 2³ +3 centrais points factorial experimental design that evaluated the influence of biomass dilution, foaming agent concentration (Porto gel) and agitation time on the physical characterization of the foam. The results indicated that the optimal combination to obtain a stable and high-quality foam is: ½ dilution, 20% foaming agent concentration and agitation time of 16 minutes. Under these conditions, the foam showed excellent properties, including air entrainment of 283%, density of 0.232 g/cm³ and excellent stability, with no collapse after 2 hours. Furthermore, an inverse relationship was observed between foam density and air entrainment, suggesting that lighter and more porous foams tend to be more stable. For powder production, since dilution is a crucial factor in foam production, a new 22 + 2 centrais points factorial experimental design was designed, setting the maximum dilution at 1:2 and the agitation time at 16 minutes, with the foaming agent concentration and drying temperature as inputs variables and the drying time and final moisture content as response variables. The experiments performed showed that temperature is the main factor influencing the drying kinetics of Saccharomyces cerevisiae yeast powder. Comprehensive physical-chemical tests were performed to characterize the powder obtained after drying, including analyses of moisture, soluble solids, water activity, pH, ash content, lipids, proteins, carbohydrates, granulometry and process yield. The results showed that the material presented low moisture content of 7.06% and water activity of 0.195 at a temperature of 45ºC, indicating stability for prolonged storage, average content of 13% proteins, 12% lipids and 38% carbohydrates suggesting potential as a nutritional supplement for animals and high ash content (20%), indicating the presence of mineral salts and vitamins essential for animal diet. The granulometric analysis classified the yeast powder as ultrafine. The results achieved define a new paradigm for the use of yeast biomass in drying processes and create promising perspectives for applications such as animals nutritional supplementation.