Engineering Implementation of the Acosta Fermentation Method to Obtain Cuban Schnapps with Reduced Concentrations of Higher Alcohols

Abstract

The Acosta method involves rewiring the yeast metabolic pathway to enhance biomass production and prevent a significant increase in higher alcohols during the late stages of fermentation. This study aimed to assess fermentation conditions to achieve Cuban schnapps with reduced concentrations of higher alcohols and replicate the process on an industrial scale. To achieve this, the quality of final sugarcane molasses for fermentation by Saccharomyces cerevisiae (S. cerevisiae) yeast was evaluated. Industrial pre-fermentation and fermentation processes were successfully conducted, followed by laboratory-scale fermentation using the Acosta fermentation method to determine crucial parameters for industrial implementation. Operational parameters for fermentation were identified from the following results: 13.5 °Brix seeding, metabolic pathway inversion of S. cerevisiae at 16 h, and an air concentration of 0.1 m3/min. The resulting Cuban schnapps obtained using this method exhibited a concentration of higher alcohols of 132.5 mg/L, a value that is within the standard parameters, showing a positive impact of this fermentation method on the quality of the schnapps. Scaling up this method to an industrial level, in addition to offering higher quality products and being an economically viable alternative, also stands out for its sustainable and environmentally friendly aspect, and results in higher production of yeast biomass as a byproduct, which can be used for various purposes, such as animal feed. This method constitutes an important update to the schnapps production process as a technological improvement that respects sustainable production trends and the characteristics of the final product.