Capacidade fermentativa da Saccharomyces cerevisiae imobilizada em alginato de cálcio para produção de cerveja

Abstract

Fermentation is one of the most important stages for beer production, forming the main products of the drink, alcohol and carbon dioxide, in addition, compounds are generated, desired or not, responsible for characterizing it sensorially. The immobilization technique has been widely used in several industrial segments. In the fermentation process, the immobilization technique allows better handling of the biocatalysts, improves the control and long-term stability of the cells, protects the cells against shear forces and increases the cell density inside the capsules. Considering fermentation to be a critical and very important stage, this work evaluated the viability of the process combined with fermentation cycles of a pure malt beer in a batch system using Saccharomyces cerevisiae yeasts immobilized in calcium alginate. The project consisted of the study of fermentation with yeasts immobilized in a volume of 20ml and 20L, and a volume of 10L for the evaluation of the reuse of yeasts. Alcohol production, substrate consumption and viability of the microorganism were analyzed throughout the process, as well as the sensory characteristics of the product. The study indicated a similarity between the kinetic profiles of the fermentation in volume of 20ml and 20L, in which they presented a yield of 85.7% and 83.9%, respectively. The biocatalysts were reused in 4 batch fermentations, with 87.79% yield at the end of the last fermentation. The sensorial evaluation indicated the existence of a significant difference between the samples with free and immobilized yeasts.