Comparative Study of Kissiris, γ-Alumina, and Calcium Alginate as Supports of Cells for Batch and Continuous Wine-Making at Low Temperatures

Abstract

Kissiris, γ-alumina, and calcium alginate were the supports for immobilization of a cryotolerant and alcohol-resistant strain of Saccharomyces cerevisiae species. Continuous wine-making with immobilized cells on each above support was performed at ambient and low temperatures. To evaluate the results of continuous wine-making with immobilized cells, batch fermentations were performed using immobilized and free cells separately, in the same range of temperatures. Fourfold higher ethanol productivities at room temperature and 10-fold higher productivities at low temperatures were obtained by continuous wine-making, in comparison to batch fermentations performed with free cells. Specifically, at 7 °C, ethanol productivities achieved by continuous wine making were 16.7, 13.8, and 23.2 g L-1 day-1 and by batch wine-making were 4.5, 5.1, and 5.6 g L-1 day-1, respectively, for kissiris, γ-alumina, and calcium alginate. For free cells ethanol productivity was 1.5 g L-1 day-1 at 7 °C. The three continuous systems were operated continuously for 80 days without any infection and diminution of the ethanol productivity. Also, the wines were produced with low total and volatile acidities. Keywords: Alcoholic fermentation; wine; continuous; batch; immobilized cells; Saccharomyces cerevisiae; psychrotolerant strain