SANGORRIN marcela paula
Patagonian wines: implantation of an indigenous strain of Saccharomyces cerevisiae in fermentations conducted in traditional and modern cellars
LOPES, C.A.; RODRIGUEZ, M.E.; SANGORRIN, M.P.; QUEROL, A.; CABALLERO, A.C.
JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY
Año: 2007 vol. 34 p. 139 - 149
In this work we evaluate the implantation capacity of the selected S. cerevisiae indigenous strain MMf9 and the quality of the produced wines in a traditional (T) and a modern (M) cellar with diVerent ecological and technological characteristics in North Patagonia (Argentina). Red musts were fermented in 10,000 l vats using the indigenous strain MMf9 as well as the respective controls: a fermentation conducted with a foreign starter culture (BC strain) in M cellar and a natural fermentation in T cellar. Since commercial S. cerevisiae starters are always used for winemaking in M cellar and in order to compare the results,natural fermentations and fermentations conducted by the indigenous strain MMf9 were performed at pilot (200 l) scale in this cellar, concomitantly. Thirty indigenous yeasts were isolated at three stages of fermentation: initial, middle and end. The identiWcation of the yeast biota associated to viniWcations was carried out using ITS1-5.8S-ITS2 PCR-RFLP. The intra-speciWc variability of the S. cerevisiae populations was evaluated using mtDNA-RFLP analysis. Wines obtained from all fermentations were evaluated for their chemical and volatile composition and for their sensory characteristics. A higher capacity of implantation of the indigenous MMf9 strain was evidenced in the fermentation carried out in M cellar (80% at end stage) than the one carried out in T cellar (40%). This behaviour could indicate that each cellar diVers in the diversity of S. cerevisiae strains associated to wine fermentations. Moreover a higher capacity of implantation of the native starter MMf9 with regard to the foreign (BC) one was also found in M cellar. The selected indigenous strain MMf9 was able to compete with the yeast biota naturally present in the must. Additionally, a higher rate of sugar consumption and a lower fermentation temperature were observed in viniWcations conducted by MMf9 strain with regard to control fermentations, producing wines with favourable characteristics. Even when its implantation in T fermentation was lower than that observed in M one, we can conclude that the wine features from MMf9 fermentations were better than those from their respective controls. Therefore, MMf9 selected indigenous strain could be an interesting yeast starter culture in North Patagonian wines.