Application of a New Organic Yeast Immobilization Method for Sparkling Wine Production

Abstract

The efficiency and effectiveness of a new immobilizing yeasts format to produce sparkling wines by traditional method was examined. The innovative cell entrapment organic system, named biocapsules, was accomplished by the natural and spontaneous co-immobilization of a Saccharomyces cerevisiae strain and a filamentous fungus (Penicillium chrysogenum). The behavior of this immobilization method was compared with the activity of the same yeast strains in free cells format and immobilized in calcium alginate beads. Two Saccharomyces cerevisiae strains were used as starters and two different base wines were tested. Metabolic kinetics of the organic biocatalyst during second fermentation, enological features, foam properties and sensory profile of the produced sparkling wines after ten months of aging were analyzed. Immobilization supports had an influence on fermentation kinetics, as well as the enological characteristics of base wine used. Unfermented sugars were found in some of the immobilized yeasts batches. Chemical features assessed in the final products did not show relevant enological differences, with the exception of the content in calcium ion, slightly higher in sparkling wines made with yeasts immobilized in calcium alginate beads. The foaming properties of batches produced with yeasts in biocapsules obtained similar or better values than those fermented with free cells. A discriminant analysis performed with the enological and foam data allowed distinguishing among sparkling wines made with biocapsules and the other two yeast inoculum formats. A triangular test reported no significant differences among inoculating yeast forms in most of the batches. The results suggested that biocapsules might be a low cost, natural and suitable yeast immobilization method for sparkling wine production.