IVAS Session 6 – Posters

The brown marmorated stink bug (BMSB, Halyomorpha halys Stal) is an invasive pentatomid native to eastern Asia that is spreading rapidly worldwide, notably through human-mediated activities. Globally, it was reported in the USA, Canada, Italy, Hungary, and other European countries. BMSB has a broad host range that includes over 170 plants, many of agricultural importance, including various fruit, vegetables, row crops, and ornamentals. When present in the vineyard, the pest can affect yield and quality by directly feeding on berries resulting in fruit collapse and necrosis. Additional damage occurs when BMSB are carried into the winery within the grape clusters. The presence of BMSB during wine processing can affect juice and wine quality through the release of volatile compounds produced as a stress response. The major secretes compounds are tridecane and trans-2-decenal. Tridecane is an odorless compound and its effect on wine quality is currently unknown. Trans-2-decenal is an unsaturated aldehyde considered to be the main component of BMSB taint with strong green, coriander, and musty-like aromas. Its threshold value in wine was estimated at about 5 µg/L.

The quality of wine is difficult to define. This is most certainly accredited to everyone´s different perception of quality. Some of the indicators of high-quality wines are complexity, balance, color and intensity. Color is one of the most crucial attributes of quality, not only for the obvious implications for their perception but also because they are indicators of other aspects related to its aroma and taste. Phenolic compounds are the main responsible for wine color, being anthocyanin and tannins the most determinant compounds in red wines. In addition to color, wine aroma is another important attribute linked with quality and consumer preferences.

Concepts such as typicality are difficult to demonstrate using the limited set of samples that can be subjected to sensory evaluation. This is due both to the complexity of the concept and to the limitations of traditional sensory evaluation (number of samples per session, panel fatigue, the need for multiple sessions and methods, etc.). On the other hand, there is a large amount of data already available, accumulated through many years of consistent evaluation. These data are held in repositories (such as Platter’s Wine Guide in the case of South Africa Wine, wineonaplatter.com) and in technical notes provided by the producers.

Global climate change is exerting an influence on vine phenology, leading to a decoupling of technological and phenolic maturity of grapes. This results in the modification of berry chemical composition, which can translate into wines with excessive astringency. The addition of mannoproteins (MP) to wine has been proposed as a way of mitigating this problem, since some studies have shown that MPs can modulate wine astringency. However, the mechanism underlying the astringency modulation effect of MPs is not well known and it seems to be dependent on the compositional and structural characteristics of the MP.

Wine research in the past years has mainly been focused on laboratory scale due to the possibility of controlling winemaking variables. Conversely, studies on wine quality in relation to the winemaking variables at the winery scale may be able to better account for the actual challenges encountered during wine production. Winemaking problems are recently arising from progressive changes in environmental conditions in relation to the terroir. It is important to realize that each wine region may have specific winemaking protocols and that winemakers often base their decisions on subjective, emotional, and empirical opinions. Due to all the above-mentioned issues, taking the correct decision in winemaking to achieve the desired goals may become even more challenging.

As a result of climate change consequences, there is a gap between the times at which the grapes reach the phenolic and the technology maturities.

Does a white wine smell like red wine if you color it with red food coloring? A study by Morrot, Brochet, and Dubourdieu (2001, Brain and Language) suggests so. Subjects perceived red wine odors when tasting white wine that had been colored red. The perceived odor profile of the colored white wine became similar to that of a red wine. However, the forced-choice procedure used by Morrot et al. has some methodological shortcomings. Here, we used an alternative method (a rating procedure) to evaluate the presented wines.

Among the Vitis vinifera L. cv. Moscato, Moscato Bianco is the oldest and most cultivated one in Europe (1). According to the OIV Focus 2015, Italy is the country with the largest cultivated area of Moscato Bianco with about 12500 hectares (2), that is used to produce well-known wines (i.e., Moscato Passito in Piedmont, Moscato di Trani in Puglia, and Moscatello di Montalcino in Tuscany), mainly obtained from partially dehydrated grapes (1). Different dehydration techniques can strongly modify the chemical compounds of oenological interest, among which Volatile Organic Compounds (VOCs) (1) that are the main responsible for the varietal sensory character of the final wine.

With the steady rise in wildfire occurrence in wine regions around the world, there are quality issues beginning to face the wine industry. These fires produce clouds of smoke which have the ability to carry organic molecules across vast distances that can be absorbed by grapes. When these compounds make their way into the final wine, unpleasant smokey and burnt flavors are present, along with a lasting ashy finish. Along with the volatile compounds carried by smoke, once incorporated into the fruit these compounds become bound to sugars, forming glycosidic compounds.

Monferace project is born from an idea of 12 winegrowers willing to create a new “old style” Grignolino wine and inspired byancient winemaking techniques of this variety (1). Monferace wine is produced with 100% Grignolino grapes after 40 months of ageing, of which 24 in wooden barrels of different volumes. Grignolino is an autochthonous Italian variety cultivated in Piedmont (north-west Italy), recently indicated as a “nephew” of the famous Nebbiolo (2) and is used to produce three different DOC wines. The Monferace Grignolino is cultivated in the geographical area identified in the Aleramic Monferrato, defined by the Po and Tanaro rivers, in the heart of Piedmont and the produced wine is characterized by a high content of tannins, marked when young, that evolve over the years. Its color is generally slight ruby red and garnet red with orange highlights with ageing.

Wine quality is defined by sensory and physico-chemical characteristics. In particular, sensory features are very important since they strongly condition wine acceptability by consumers. However, the evaluation of sensory quality can be subjective, unless performed by a tasting panel of experienced tasters. Therefore, it is of great relevance to establish relationships between objective chemical parameters and sensory perceptions, even though the complexity of wine composition makes it difficult. In this sense, more reliable relationships can be found for a particular wine typology or variety. The present study aimed to predict the perceived sensory quality from the physico-chemical parameters of ‘Barbera d’Asti’ DOCG red wines (Italy).

Astringency has been defined by the American Society for Testing Materials as “the complex of sensations due to shrinking, drawing or puckering of the epithelium as a result of exposure to substances such as alums or tannins”. Regarding the importance of astringency in wine consumer acceptance, elucidating the molecular mechanisms underpinning this complex sensation represents an important goal for scientists. Although different mechanisms have been described (Gibbins & Carpenter, 2013), the salivary protein precipitation is still the most accepted theory. According to this, wine astringency perceived in the oral cavity is originally attributed to the interaction and subsequence precipitation of salivary proteins by wine tannins –mainly flavanols–.

In Valtellina zone (north Italy), the winemaking of ‘Nebbiolo’ grapes leads to the production of two main wine types: classic red wines from fresh grapes, usually classified as Valtellina Superiore DOCG (mandatory oak aging) or Rosso di Valtellina DOC, and the Sforzato di Valtellina DOCG, which is produced using withered grapes according to traditional product specification and subjected to mandatory oak aging process. The withering process influences grape chemical composition and, in turn, the wine sensory profile, which is strongly linked to the wine quality and typicity perceived by consumers.

The use of toasted vine-shoots as an alternative enological tool to make differentiated wines has generated interest among researchers and wineries. However, the evolution of these wines in bottle and the effect on the sensory profile has not been studied so far.