Effect of spray with autochthonous Trichoderma strains and its secondary metabolites on the quality of Tempranillo grape

The study conducted various fermentations of different grape juices using various strains of Lachancea thermotolerans and one strain of Saccharomyces cerevisiae. Because of the new conditions caused by climate change, wine acidity must be influenced as well as the volatile profile. Non-Saccharomyces yeasts such as L. thermotolerans are real options to mitigate the impact of climate change in wine production.

Secondary (or specialised) metabolites such as terpenes and phenolic compounds are produced by plants for various roles which include defence against pathogens and herbivores, protection against abiotic stress, and plant signalling. Additionally, these metabolites influence grapevine quality traits such as colour, aroma, taste, and nutritional value. However, the biosynthesis of these metabolites is often complex and controlled by multiple genes which in grapevine are predominantly uncharacterised.

Enzymatic browning[1] is an oxidation process that occurs in many foods that increases the brown colour[2]. This problem is especially harmful in the wine industry[3]. especially when the grapes are infected by grey rot since this fung release the oxidative enzyme laccase[4]. In the particular case of red wines, the presence of laccase implies the deterioration of the red colour and can even cause the precipitation of the coloring matter (oxidasic haze)[5].

In the production of sparkling wines, during the second fermentation, mannoproteins are released by yeast autolysis, which affect the quality of the wines. The effect of mannoproteins has been extensively studied, and may affect aroma and foam quality. However, there are no studies on the effect of other polysaccharides such as those from grapes. Considering the large production of waste from the wine industry, it was proposed to obtain polysaccharide-rich extracts from some of these by-products[1].

This study examines how people who consume wine in cans are perceived in terms of their basic personality characteristics, helps understand the role of cultural background on people’s perception, and verify the role played by the consumption context on the perception. Our hypothesis is that prejudice and negative attitudes towards wine in cans might exert a negative effect on the evaluation of people who consume canned wine. To evaluate this hypothesis, the consumption of wine in cans was evoked in four different contexts of use during outdoor leisure activity (beach resort, ski resort, desert safari, and party). In order to examine the effect of culture on subject’s response we use participants from Switzerland, a country where three different cultures, associated with three different languages, cohabit.