YEAST-LACTIC ACID BACTERIA MIXED STARTER FOR HIGH QUALITY PATAGONIAN RED WINE ELABORATION

YOLANDA LETICIA CURILÉN; SEBASTIÁN MARIO EZEQUIEL BRAVO; MATURANO RAMONA DEL CARMEN; VIVIANA ANDREA CARREÑO; RIVAS GA; BRAVO- FERRADA BM; DELFEDERICO L ; SEMORILE L; ADRIANA CATALINA CABALLERO

San Miguel de Tucumán

Simposio; V Simposio Internacional de Bacterias Lácticas; 2016

Centro de Referencia para Lactobacilos (CERELA)

In Argentinean Patagonia region, malolactic fermentation (MLF) is carried out by lactic acid bacteria (LAB) naturally present in the musts. Previous studies have been demonstrated that yeast-LAB interactions could significantly influence the FML development in a negative way. The aims of this work were to evaluate the potential interactions between Patagonian indigenous yeast and LAB strains with appropriate oenological properties and to select the most suitable yeast-LAB pair for its use as mixed starter in red winemaking. The assays to evaluate interactions were carried out at 22±2°C at laboratory scale (200 mL), using a sequential inoculation strategy. Wines obtained from Pinot noir and Malbec must fermented (1000 mL) using pure culture of indigenous S. cerevisiae F8 (Sc F8) strain were filtered with 0,2 μm membranes and they were inoculated with Patagonian indigenous Oenococcus oeni strains (107cell mL-1) noted as UNQOe 31, UNQOe 73, CCNP 3001 and CCNP 3002. The evolution of the alcoholic fermentation (AF) and the MLF was evaluated by total reducing sugars (TRS, colorimetric method) and L(-) malic acid (enzymatic method) quantification, respectively. Growth of yeast and LAB was quantified by viable count on YEPD and MLO agar, respectively. These experiences allowed selecting the pair ScF8-UNQOe 31 as the most suitable and they were used as mixed starter in vinifications carried out at pilot scale (200 L). Sulfited Pinot noir and Malbec musts were inoculated with 107cell mL-1 of indigenous Sc F8 or commercial S. cerevisiae F15 (Laffort) starter (control). At the end of AF, young wines were splited into two 50 L batches and transferred to two tanks where spontaneous or UNQOe 31 guided MLF were developed at 20  2 ºC. The fermentative and microbial growth kinetics was performed as described above. The capacity of the selected indigenous strains to dominate AF and MLF was evaluated using molecular methods (mitDNA RFLP and RAPD patterns, respectively). Wine quality was evaluated through physicochemical parameters (INV methods), sensorial analysis and consumer preference polls. All vinifications yielded normal products. However, wines obtained from guided fermentations using the pair ScF8-UNQOe 31 were significantly improved in their fruity aromatic attribute (ANOVA and Tukey test p<0,05), allowing to obtain a higher score than their controls in the sensorial evaluation by tasting and to be preferred for the consumers (Bonferroni test p<0.05). These results evidence the oenological potential of the pair ScF8-UNQOe 31 to formulate a regional starter culture for the production of high quality Patagonian young red wines (premium wines).