Abstract
Mead is an alcoholic beverage obtained by yeast fermentation of diluted honey. Crystallized honey is not appreciated in Colombian market because people think that this type of honey is false, so it is a cheap and excellent raw material for mead production, providing an important economic alternative for beekeeping chain in this country. The main objective of this work is to assess the fermentative process in mead production by using cells of Saccharomyces cerevisiae immobilized in carrageenan and to compare the process with free cells fermentation. Beads of carrageenan were made by the gellification method and the best conditions for it were stablished testing the beads formed in various KCl solutions. 2% (w/v) and 3% (w/v) carrageenan solutions were tested in 2%, 8%, 12% and 16% (v/v) KCl solutions for evaluation of beads formation. The beads were evaluated on its texture properties by a texture profile analysis. The spheres formed in solutions of 3% (w/v) carrageenan and 16% (w/v) potassium chloride showed the best texture results. Fermentation assays were carried out at 30 °C to compare free and immobilized cells, honey was diluted with water to 24 °Bx and pollen was used as nitrogen source. Glucose, fructose and ethanol concentrations were evaluated during the fermentation. Productivity and yield values showed significant differences; productivity with free cells is higher but efficiency with immobilized cells showed the best result. It was possible to reach a better yield, 0.40 g ethanol/g sugar, higher ethanol concentrations in the final product in a fermentation with immobilized cells (11.7% v/v in immobilized, 9.9% v/v in free cell), showing the advantages of the immobilization applied in mead production.
