Polyphenols in Wine Authenticity

Polyphenols are a diverse group of compounds of utter importance to wine quality. Current understanding of the polyphenolic composition in wine is well elaborated, however, recent studies continuously report novel findings involving them. It is evident that synergistic approaches between emerging analytical platforms in combination with advanced multivariate data analysis will be considered the spearheads toward fraud detection and the provision of authentic wines.

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Is the “Pied de Cuve” a credible alternative to manage indigenous alcoholic fermentation?

Winemakers are increasingly keen to limit the use of commercial yeasts in order to reduce oenological inputs. The preparation of an indigenous winery-made fermentation starter from grapes called ‘pied de cuve’ (PdC) is becoming popular, especially in organic farming systems. However, the implementation of the PdC method is still empirical and knowledge is lacking regarding the impact of PdC on S. cerevisiae diversity during alcoholic fermentation. This post reports the results where the impact of PdC on S. cerevisiae genetic diversity and wine composition was evaluated at an industrial scale.

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A study of regionality in Australian Pinot noir wines demonstrates that NMR and ICP-MS could be used to detect wine fraud

Wine quality and character are defined in part by the terroir in which the grapes are grown. Metabolomic techniques, such as nuclear magnetic resonance (NMR) spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS), are used to characterise wines and to detect wine fraud in other countries but have not been extensively trialled in Australia. This post describes the results of a study where ICP-MS and NMR were used to characterise a selection of Pinot noir wines.

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Evaluation of the intrinsic and perceived quality of sangiovese wines from California and Italy

The results from this study confirm that perceived quality in terms of typicality of Sangiovese was still related not only to fruity and floral flavors but also to lightness and freshness, despite the intrinsic quality aspect of the “structure” of the wine and to what is considered a “good” color. Moreover, the findings confirm that Sangiovese shows a flexibility in terms of chemical and sensory modification, according to the production area and that it can be considered typical even if it comes from an area far away from the traditional ones.

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The use of immobilized kefir cells on natural zeolites in winemaking

In this post the author summarize a study carried out to investigat the use of natural zeolites, an inorganic support with multiple technological advantages, for kefir culture immobilization and subsequent evaluation in winemaking at various temperatures (5–45 °C). The results indicated the high potential of immobilized kefir culture on natural zeolites in scale-up industrial applications and suggested their exploitation in the development of low alcohol wines and wines with a semi-sweet character.

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Extended harvest date alter flavonoid composition and chromatic characteristics of Plavac Mali (Vitis vinifera L.) grape berries

This post is about a study that delivers a comprehensive flavonoid fingerprint profile, physiochemical and external color characterization of Plavac Mali grapes through four harvest dates at two distinct vineyards (Split and Zadar) in the Eastern Adriatic region. Results show that berries of extended harvest dates underwent colorimetric improvements, trough decrease in CIELab color space parameters a* (reed/green), b* (yellow/blue), L* (lightness (0, black; 100 white)) and C (chroma, relative saturation) characteristics and increase in skin color index for red grapes. In conclusion, the extended harvest date promotes flavonoid composition, and improves the quality of Plavac Mali grape berries.

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Loss of trans-resveratrol in young red wines

In general, cis-resveratrol shows fewer health effects than trans-resveratrol, including its anti-inflammatory power. According with this study it is possible that older red wines will not provide the same degree of health benefits compared to younger red wines. However, further work is required to confirm the dependency of resveratrol flux on the age of the wine in question.

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Understanding wine’s more abstract attributes

This post reports the results of a study carried out to investigate (i) attributes driving wine professionals’ judgments of quality and complexity in Pinot noir wines; (ii) the relation between these two abstract concepts; and (iii) association of each concept with varietal typicality. The key drivers of perceived quality were descriptors varietal typicality, expressiveness, overall structure, and attractive fruit aromatics, along with complexity questionnaire attributes of harmony, balance, and number of identifiable flavours. Results show that quality and complexity were positively associated concepts and that both were linked positively with varietal typicality. Visual influence was not a major driver of wine professionals’ judgments but being able to see a wine’s colour influenced tasters’ judgments to wines at each end of the price/quality spectrum.

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The past, present and future of wine lees valorisation

Wine lees, a sludge material mainly composed of dead yeast precipitated at the bottom of wine tanks, is one of the main by-products of the winemaking industry. Since wine lees are considered a soil pollutant, it is important to find strategies for their recovery and valorization. In this post the authors discuss wine lees valorization strategies. Authors highlight the importance of an integrated approach tailored to extract the highest number and amount of compounds with potential applications in different sectors, thus improving also the environmental and economic sustainability of the whole wine supply chain.

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Phenolic composition, quality and authenticity of grapes and wines by vibrational spectroscopy

Due to its great importance on the structure, flavour and color of wines, phenolic compounds have been determined along time by different instrumental techniques combining physical and chemical methodologies. This post describes innovative analytical systems, based on spectroscopy, which can analyse complex chemical samples like wine. These are fast, accurate and eco-friendly methods with high potential to be used in wine industry.

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