IMPACT ON CHITOSAN APPLICATION OF DIFFERENT MICROORGANISMS HAVING OENOLOGICAL INTEREST

The main scope of this research has been to investigate what values are attributed to the concept of “sustainability” by the wine producers of two different wine territories of Piedmont; the terroir of the Barolo DOCG and the the terroir of the Gavi DOCG. The research wants to emphasize how much the characteristic elements of each terroir influence the perception of the concept of sustainability among producers.

Pruning is one essential vineyard management activity whose main purpose is to regulate plant growth and vigour, modulating berry size, and consequently, wine quality. In Chilecito, La Rioja Province, Argentina, Torrontés Riojano stands as the only autochthonous variety for winemaking, yielding golden and aromatic berries and distinctive muscatel-tasting wines. This white cultivar, resulting from the natural cross between Moscatel de Alejandría x Criolla Chica, is traditionally trained in “parral” (horizontal trellis system), aimed to manage vigorous canopies. This project constitutes the first study on the influence of pruning intensity on Torrontés Riojano growth habit and berry quality.

Bacterial malolactic fermentation (MLF) has a considerable impact on wine quality. The yeast strain used for primary fermentation can consistently stimulate (MLF+ phenotype) or inhibit (MLF- phenotype) malolactic bacteria and the MLF process as a function of numerous winemaking practices, but the molecular evidence behind still remains a mystery. In this study, such evidence was elucidated by the direct comparison of extracellular metabolic profiles of MLF+ and MLF- yeast phenotypes. Untargeted metabolomics combining ultrahigh-resolution FT-ICR-MS analysis, powerful machine learning methods and a comprehensive wine metabolite database, discovered around 800 putative biomarkers and 2500 unknown masses involved in phenotypic distinction.

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines.

Egri Bikavér (Bull’s Blood) is one of the most remarkable Hungarian red wines on inland and foreign markets as well. From the end of the 70’s the quality of Egri Bikavér was decreasing continually due to mass production. The concept of production of quality wines became general in the mid 90’s again and it resulted in a new Origin Control System, for the first time that of Egri Bikavér in Hungary.