How wine fluorophores dialog with us to evaluate fermentative steps during winemaking practices?

In this study, stationary and time-resolved fluorescence signatures, were statistically and chemometrically analyzed among three typologies of Chardonnay wines with the objectives to evaluate their sensitivity to acidic and polyphenolic changes. The combination of multispectral fluorescence parameters opens a novel routinely implementable methodology to diagnose fermentative processes.

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Health warning labels on wine bottles and how they influence perceived risk of consumption

Wine is an essential part of European culture. Unfortunately, the consumption of alcohol, such as wine, can have negative health effects. Health warning labels (HWLs) are increasingly presented as a measure to warn consumers of the threat alcohol poses to their health. At present, only a few countries in Europe have introduced mandatory HWLs on wine bottles. This may be due to the cultural and economic significance of wine and the European public’s refusal to accept HWLs on a product like wine. To investigate this issue, the authors conducted an online experiment in the German-speaking part of Switzerland and assessed the perception of risk in participants who were presented wine bottles featuring different types of HWLs. They also studied how health beliefs and cultural worldviews influence the perception and acceptance of HWLs. The study revealed a small effect of HWLs on consumers’ risk perception. There was no difference between a simple text-only HWL and a label featuring a deterring picture (image-and-text HWL). The major determinants of HWL acceptability were cultural worldviews and health beliefs. That is, participants who opposed government intervention for collective wellbeing and espoused a belief in the health benefits of wine were less likely to accept HWLs on wine. More research is needed to assess the effectiveness of HWLs in real-life situations and the importance of culture to the acceptance of such a public intervention measure.

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Ancient origins of modern wines

Wine was being made almost 8.000 years ago! The earliest known wine remains, which were discovered in clay jars from the South Caucasus in Georgia, have been attested by chemical analysis to date to ca. 6.000–5.800 BCE. This agrees with climatic and environmental reconstructions, as well as with archaeobotanical evidence, which points to Georgia being the cradle of viticulture and wine making (McGovern et al. 2017). Not far from Georgia, in the Zagros Mountains in northwestern Iran, wine remains dated to ca. 5.400 BCE have been preserved in pottery vessels together with traces of resin, which might have been added as a preservative (McGovern 2003). This suggests that early Iranian wine had a similar taste to the Greek retsina of today, to which pine resin is added during the fermentation process. Does this mean that all ancient wines had this resinated taste? Not necessarily! The ancient written sources, when approached from an oenological point of view, suggest that ancient Greek and Roman wine makers were quite advanced, as they could produce many of the drinks that we know today.

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Origin of wine lignans

Plant lignans possess several properties beneficial for human health and therefore, increasing their contents in foods and beverages is desirable. One of the lignan sources in human diet is wine. To elucidate the origin of lignans contained in wine, LC-MS was used to analyze resinol-related lignans in must, seeds, stems, and wine prepared using stainless steel tanks, oak barrels, and Qvevri (clay vessel). White wines aged in stainless steel tanks contained significantly lower amounts of lignan aglycones (20-60 µg/L) than red and Qvevri wines (300-500 µg/L). Generally, white wines aged in stainless steel tanks contained only low amounts of isolariciresinol and matairesinol. Qvevri wines and red wine aged in stainless steel tank contained up to five lignan compounds and in wine aged in oak barrel, six different lignans were identified. Consistently, only low concentration of isolariciresinol has been found in must, whereas more lignan compounds have been found in grape seeds (isolariciresinol, secoisolariciresinol, and pinoresinol) and stems (isolariciresinol and syringaresinol). Consequently, we conclude that lignan content in wine can be increased by maturation in contact with grape berries, seeds, or stems or with wood.

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Towards a sustainable viticulture: The combination of deficit irrigation strategies and agroecological practices in Mediterranean vineyards. A review and update

This post summarizes a review of the state of the art of different physiologically-based water-saving irrigation strategies and methods used to improve productive water use efficiency and berry and wine quality in vineyards. Authors also show how these irrigation practices, combined with more sustainable soil management and other agroecological practices, can help to mitigate the negative effects of climate change on wine grapes cultivation and make irrigated Mediterranean vineyards more resilient and sustainable. The authors also review optimum vine water status ranges and the thresholds proposed for better deficit irrigation scheduling in vineyards. In addition. They consider sustainable soil management practices – such as cover crops, mulching, composting, reduced tillage, mutualistic plant-microorganisms interactions, and agroforestry . The idea is to design sustainable and climate-change-resilient agricultural systems (e.g. vineyards) in Mediterranean semi-arid areas.

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Correlating wine astringency with physical measures – current knowledge and future directions

Oral tribology receives growing attention in the field of food sciences as it offers great opportunities to establish correlations between physical parameters, such as the coefficient of friction, and sensory effects when interacting with components of the human mouth. One important aspect covers the astringency produced by wine, which can be described as the sensation of dryness and puckering in the mouth, specifically occurring between the tongue and the palate after swallowing. Therefore, this post reports the resulst of a study which aims at shedding some light on recent trends to correlate physical measures, such as the coefficient of friction derived by oral tribology, with prevailing theories on underlying physiological causes for sensory perception of wines. Some successful cases reported the potential of correlating wine astringency perception with the coefficient of friction in tribological experiments. Our critical assessment demonstrates that the findings are still contradictory, which urgently asks for more systematic studies. Therefore, the authors summarize the current challenges and hypothesize on future research directions with a particular emphasis on the comparability, reproducibility and transferability of studies using different experimental test-rigs and procedures.

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Quality of Malvasia delle Lipari Sweet Wine influenced by bottle colour, light and storage temperature

The influence of light exposure, bottle color and storage temperature on the quality parameters of Malvasia delle Lipari (MdL) sweet wine were investigated. Wine samples bottled in clear-colored (colorless, green and amber) glass were stored under different artificial lighting conditions, in order to simulate the retail environment (one cool-white, fluorescent lamp) and to perform an accelerated test (four and six cool-white, fluorescent lamps). The storage temperature was kept constant (25 °C) for the first 90 days of the experiment and then samples were monitored for up to 180 days at higher temperatures (30, 35 and 40 °C). The principal enological parameters, total phenols, color, 5-hydroxymethylfurfural (HMF) and 2-furaldehyde (2F) contents were studied. The shelf-life test pointed out minimum variations of the basic chemical parameters, while the quality attributes most affected by lighting were color, together with HMF and 2F levels which, hence, can be considered as indicators of the severity of storage conditions.

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Machine Vision for Ripeness Estimation in Viticulture Automation

Ripeness estimation of fruits and vegetables is a key factor for the optimization of field management and the harvesting of the desired product quality. Typical ripeness estimation involves multiple manual samplings before harvest followed by chemical analyses. Machine vision has paved the way for agricultural automation by introducing quicker, cost-effective, and non-destructive methods. This work comprehensively surveys the most recent applications of machine vision techniques for ripeness estimation. Due to the broad area of machine vision applications in agriculture, this review is limited only to the most recent techniques related to grapes. The aim of this work is to provide an overview of the state-of-the-art algorithms by covering a wide range of applications. The potential of current machine vision techniques for specific viticulture applications is also analyzed. Problems, limitations of each technique, and future trends are discussed. Moreover, the integration of machine vision algorithms in grape harvesting robots for real-time in-field maturity assessment is additionally examined.

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Influence of Climate on Soil and Wine Bacterial Diversity on a Vineyard in a Non-traditional Wine Region in Argentina

Argentina is the fifth world-wide wine producer, with an area of emerging importance in the Southwest of Buenos Aires Province, where climatic conditions are rather challenging. The authors of this post studied the variations in soil and wine bacterial diversity through three consecutive vintages, and how climatic conditions affected said diversity. During the years of the study there were two harsh climatic events, a prolonged drought that extended over two vegetative periods, and an unseasonable spring frost in 2017. The authors found that the bacterial diversity reacted to these climatic events, given that there was a shift in the taxa exclusive to soil and wine, and shared by both, through time. The results show a core of microorganisms in soil as well as in wine, belonging to different phyla that are conserved across the vintage years. A trend to an enrichment in Actinobacteria was detected in soil samples, whereas a high relative abundance of the Acetobacteraceae family and a scarcity of Lactic Acid Bacteria (LAB) were detected in the wine samples. The results of the study contribute to a better understanding of the impact of climatic conditions on the soil and wine microbiota and can provide vintners with valuable knowledge for improving their wine production.

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