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

The efficiency and effectiveness of a new immobilizing yeast method to produce sparkling wines was examined. The cell entrapment organic system, labeled 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 a free cell 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 secondary fermentation, enological parameters, foam properties, and sensory profile of the produced sparkling wines after 10 months of aging were analyzed. Immobilization supports and base wine characteristics had an influence on fermentation kinetics. Unfermented sugars were found in some of the immobilized yeast batches. Enological parameters assessed in the final products did not show relevant enological differences, with the exception of calcium ion content, which was slightly higher in sparkling wines made with yeast immobilized in calcium alginate beads. The foaming properties of batches produced with yeast in biocapsules had similar or better values than those fermented with free cells. Discriminant analysis performed with the enological and foam data distinguished among the 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.