P7
Wine strain improvement strategies to enhance red wine safety
based on parietal adsorption activity. 2. Yeast selection from
Campania and Calabria
Andrea Caridi", Rossana Sidari', Valeria Crea1,Giuseppe Blaiotta''and Alberto Ritieni''
1 "Scienze e Tecnologie Agro-Forestali e Ambientali", "Mediterranea" University of
Reggio Calabria, Via Feo di Vito, Reggio Calabria 1-89122, ITALY, Phone: +39 0965
332642, FAX:+390965817794, e-mail: aC8ridi@unirc.it,
Web:http://www.distafa.unirc.it/dett sezione.php?sect=8
2Department of"Scienza degli Alimenti", "Federico Il''University of Portici (NA)
Aim of this study was to perform a specific selection of yeasts for red winemaking.
Using a phenotypic-based methodology 83 strains of Saccharomyces cerevisiae able
to easily sporify, low H2S-producing, low acetic acid-producing, not foam producing
and exhibiting high fermentation power during red winemaking have been selected trom a major yeast collection. In a second step, a Petri plate evaluation of wine colour
adsorption phenotype of yeasts and the result confirmation by microvinification trials
were carried out, Strains were split based on their ability to adsorb phenolic grape
pigments to identify a maximum of ten strains, the lowest adsorbing ones. The 83
strains of S. cerevisiae were isolated trom musts, wines and foods (two salami, two
sourdough) trom Campania and Calabria and are included in Department of"Scienza
degli Alimenti" collection. The yeasts were studied in Petri plates for the following
biochemical characteristics: spore production on acetate agar at 25°C for 10d, H2S
production on BiGGY agar at 25°C for 48h, acetic acid production on calcium
carbonate agar at 25°C for 7d, adsorption of grape pigments on grape skin agar at
28°C far 10d (Caridi et al., 2002; 2007). The microvinification trials were performed
using Calabrian black grapes from the cultivar Gaglioppo; the grapes were
destemmed, crushed and soaked at O°C for 3 days, performing a punch down twice
per day. The must obtained after pressing was divided in aliquots of 20 mi and
termented at 20°C with the 83 pre-selected yeasts inoculated at 5% in triplicate.
Analyses were performed on diluted wine andvalues were reported considering the
dilution. Significant differences far each parameter were observed. Biomass colour
varied trom 45 to 135 (red component), from 21 to 88(green component), and from
27 to 82(bluecomponent). Wine parameters varyfrom 1.088 to 4.238(420 nm),trom
0.775 to 2.648 (520 nm), from 0.328 to 1.193 (620 nm), trom 2.192 to 8.080
(intensity), trom 1.338 to 1.739 (tint), from 8.567 to 26.683 (Folin-Ciocalteu index).
Based on these results, parietal adsorption activity is notably different among yeasts
and justifies a programme of genetic improvement. Reterences Caridi A. et al.,
(2002), J Gen Appl Microbiol, 48, 261. Caridi A. et al., (2007), J Appl Microbiol, 103,
735. This work was supported by PRIN 2007 "Wine strain improvement strategies to
enhance red wine satety based on parietal adsorption activity".
