Mixed starters Schizosaccharomyces japonicus/Saccharomyces cerevisiae as a novel tool to improve the aging stability of Sangiovese wines

Paola DOMIZIO¹, Lorenzo Portaro¹, Francesco MAIOLI¹, Valentina CANUTI¹, Monica PICCHI¹, Livio Lencioni¹, Ilaria Mannazzu²
1 Department of Agricultural, Food, Environmental, and Forestry Sciences and Technologies – University of Florence, via Donizetti, 6 – 50144 Firenze (Italy)
2 Department of Agriculture, University of Sassari, Viale Italia 39, 07100 Sassari (Italy)

Email contact: paola.domizio[@]unifi.it

AIM: In the present work Schizosaccharomyces japonicus and Saccharomyces cerevisiae were inoculated simultaneously or in sequence in mixed fermentation trials with the aim of testing their ability to improve the overall quality of red wine, in particular of Sangiovese wine.

METHODS: The impact of simultaneous and sequential inoculations on growth and fermentation kinetics and on the analytical and sensory profiles of the experimental wines was evaluated at the end of the alcoholic fermentation and 24 months after bottling with standard methods.

RESULTS: S. japonicus affected S. cerevisiae growth and fermentative capability only in the sequential fermentation. The experimental wines produced with S. japonicus and S.cerevisiae in simultaneous and sequential mixed fermentation reached concentrations of total polysaccharides respectively two- and three-fold greater than those obtained with pure cultures of S.cerevisiae. Moreover, the non-Saccharomyces yeast modulated the concentration of some of the most important wine volatile compounds. At the end of the alcoholic fermentation, ethyl acetate was significantly higher in the mixed fermentation wines in respect to the level acceptable for a young red wine. However, this metabolite underwent considerable hydrolysis during the two-years aging in bottle, with a marked decrease in its concentration. In agreement, mixed fermentation wines as compared to the control wines showed no significant differences for the ethyl acetate perception evaluated by sensory analysis carried out 24 months after bottling. Hydrolysis–esterification equilibrium in mixed fermentation wines caused an increase of acetate esters compounds responsible for fruity aroma. These ester compounds reached significantly higher concentrations in both mixed fermentation wines than in the control wine inoculated with S. cerevisiae. Moreover, all mixed fermentation wines were perceived as having lower mouthfeel sensation of astringency compared to those obtained with S. cerevisiae, possibly due to the higher polysaccharides content.

CONCLUSIONS: Based on the evidence that after 2 years of aging, mixed fermentation wines presented an increase in color stability and the concentration of fruity aroma and a decrease in astringency, the combined utilization of Sch. japonicus and S. cerevisiae might represent an innovation for the improvement of the aging stability of Sangiovese wine.

References:

• Ciani, M., Comitini, F., Mannazzu, I., Domizio, P., 2010. Controlled mixed culture fermentation: a new perspective on the use of non-Saccharomyces yeasts in winemaking. FEMS Yeast Res. 10 (2), 123-133
• Domizio, P.; Liu, Y.; Bisson, L.F.; Barile, D. Cell wall polysaccharides released during the alcoholic fermentation by Schizosaccharomyces pombe and S. japonicus: Quantification and characterization. Food Microbiol. 2017, 61,136–149.
• Domizio, P.; Lencioni, L.; Calamai, L.; Portaro, L.; Bisson, L. (2018) Evaluation of the Yeast Schizosaccharomyces japonicus for Use in Wine Production. Am. J. Enol. Vitic. 2018, 69, 266–277
• Romani, C., Lencioni, L., Gobbi, M., Mannazzu, I., Ciani, M., & Domizio, P. (2018). Schizosaccharomyces japonicus: A polysaccharide-overproducing yeast to be used in winemaking. Fermentation, 4(1), 14