Abstract

Purpuse Fodder yeast is obtained in an aerobic fermentation process where foaming is a major problem to be solved. In this article, the antifoam property of crude and purifed flter cake oil is evaluated in order to use this residual as an alternative to replace the import of commercial antifoam agents and to reduce the production costs of fodder yeast. Method Knock down test and the comparisons with two commercial antifoam agents were done. Blackstrap molasses medium at 20 and 40 g/L of total reducing sugar was used. All products were studied in their pure form and commercial ones also in dilutions 1:2 and 1:5 v/v. Hansen's solubility parameters (HSPs) to analyze the afnity of each defoamer for yeast were determined. Results It was obtained the crude and purifed flter cake oil showed similar behavior to commercial defoamers with an immediate antifoam efect, removing between 40 and 60% of the initial foam at both sugar concentrations in the frst 5 min. The regression model for both medium concentration showed purifed flter cake oil has the greatest knockdown efect (Ca=57.00 and 74.11) and with greater foam suppression stability the commercial defoamer Quimifoam Máster (Cb=−1.05 and −1.51) respectively. Ra values obtained in HSPs test, indicated the afnity of defoamers to the medium. Conclusion Purifed flter cake oil is an efective product for its use as an antifoam with the best knock down efect for both concentrations of sugars in the medium. The determination of HSPs corroborates the efectiveness of this product to suppress foam.