Rhizosphere engineering – leading towards a sustainable viticulture?

Microorganisms are a substantial component of the rhizosphere, and the activity and composition of rhizosphere microbial populations markedly affect interactions between plants and the soil environment. In addition, the microbiota of the rhizosphere can positively influence plant development, growth and vitality. In vineyards, management practices influence both grapevine root growth directly and the rhizosphere microbiota, but the exact mode of action is largely unknown. Recently, however, two new research approaches are increasingly coming into focus to enhance grapevine growth and health: plant engineering and rhizosphere engineering. In plant engineering, knowledge about plant-microbiome interactions is used for plant breeding strategies. In rhizosphere engineering, microbial communities are modified by adding specific fertilisers, nutrients or by bio-inoculation with certain bacteria and/or fungi. Taken together, these new methods suggest a potential for reaching a more sustainable development of pesticide-reduced viticulture in the future.

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Wine packaging and its impact on flavor

This is a post that summarizes a review of the most commonly available wine packaging categories. This includes glass bottles, polyethylene terephthalate bottles, bag-in-box, aluminum cans, and Tetra Pak. While glass is still the dominant packaging material within the wine industry and by consumer demand, economic and environmental concerns are driving the industry and consumers to investigate and adopt alternative packaging materials.

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How to convert a waste into a high added value product using green extraction technologies?

Food processing has been gradually adopting the use of clean technologies that aim to minimize the generation of by-products. The use of winemaking by-products for the extraction of phenolic compounds is still incipient due to the lack of fast and efficient techniques. Thus, the aim of the study summarized in this post was to use the Microwave Hydrodiffusion and Gravity (MHG) technique to extract phenolic compounds from a winemaking by-product, the grape pomace (GP). The GP had significant antioxidant properties and good yields in operating conditions of 2 W/g. Hydroxybenzoic acid, procyanidins, flavan-3-ols, and one flavanol were the phenolic compounds identified. The CP maintained the physicochemical and antioxidant properties similar to the GP.

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Grapes and vines of the Phoenicians: Morphometric analyses of pips from modern varieties and Iron Age archaeological sites in the Western Mediterranean

The present post summarizes the results of a study aimed to contribute to the investigation of the role of Phoenicians in the spreading and trade of the grapevine through the morphometric analysis of grape pips. Waterlogged and charred samples were selected from three Iron Age sites in the Western Mediterranean: Motya (Sicily, Italy), Nuraghe S’Urachi (Sardinia, Italy) and Huelva (Andalusia, Spain). While only Motya is a Phoenician foundation, all three were nevertheless associated with Phoenician expansion and cultural interaction. Ten cultivars from the “Vivaio Federico Paulsen” in Marsala (western Sicily) were chosen as modern reference material. This analysis represents a first step towards a better understanding of diachronic and synchronic relationship between vines grown in the ancient West Mediterranean, which could be expanded by analysing grape pips from more contexts and more sites, compared against a wider selection of modern cultivars.

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Astringency sub-qualities of red wines and the influence of wine-saliva aggregates

Astringency is a sensory attribute, related to the quality and mouthfeel of red wines. However, the origin of astringency sub-qualities, such as the typical drying astringency found in immature grapes, is still unknown. Astringency of red wines with similar tannin content but different astringency sub-qualities, from different harvest dates, is studied. Astringency was characterised in terms of friction coefficient, polyphenol content, sensory analysis and tannin/salivary–proteins aggregates characterisation. A different evolution during ripening was found for both Cabernet Sauvignon and Carménère, and tannin–protein aggregates showed differences in size, shape and surface. The velvety sub-quality appears to be related to aggregates with low precipitation, and with specific surface characteristics as roundness and Feret diameter. Results from this work propose an effect of aggregates on sensory perception and opens the possibility to explore their effect on oral lubrication.

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Do yeast lees always stimulate wine malolactic fermentation?

The use of non-Saccharomyces yeast together with S. cerevisiae in winemaking is a current trend. Apart from the organoleptic modulation of the wine, the composition of the resulting yeast lees is different and may thus impact malolactic fermentation (MLF). Yeasts of Saccharomyces cerevisiae, Torulaspora delbrueckii and Metschnikowia pulcherrima were inactivated and added to a synthetic wine. Three different strains of Oenococcus oeni were inoculated and MLF was monitored. This is the first study of MLF with different O. oeni strains in the presence of S. cerevisiae and non-Saccharomyces yeast lees to report a strain-specific interaction between them.

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Umami in fermented beverages

In the present post authors present a summary of the results obtained in a study where for a wide range of fermented beverages in terms of their e free amino acid (FAA) composition and they provide quantitative evidence that beverages with long yeast contact may contain larger amounts of free glutamate and hence hold a greater potential for imparting umami than beverages with no or little yeast contact. To the extent that umami-synergy is a key in pairing fermented beverages and foodstuff, the results presented in the present post may be useful for practitioners in the restaurant and beverage business. For example, it may provide a quantitative basis for the claim that sake is also a good companion with shellfish and other fish and that some beers may be just as good as long-time fermented wine and champagnes in terms of umami taste pairing of food and beverages.

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Increasing the use of mechanized grape harvesting

Due to the low number of employees and the time limit in the field of grape harvesting, the authors presented in this post the results of an evaluation of the effectiveness of the deployment of an outboard grape harvester within the conditions of Slovak viticulture. The post evaluates the dependence of the use of mechanized harvesting on changes in the purchase price of grapes (increasing it also exponentially increases the required area) and on changing the hourly wage of an employee (increasing it degressively reduces the required area). From the results it can be said that statistically and economically significant outputs were achieved for the deployment of machine collection.

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Is the second-cheapest wine a rip-off?

The second-cheapest bottle on a restaurant wine list is widely thought to be priced to exploit naïve diners embarrassed to choose the cheapest option. This post it is a summary of an investigation whether this behavioral theory holds empirically. The authors find that the mark-up on the second-cheapest wine is significantly below that on the four next most expensive wines. It is therefore an urban myth that the second-cheapest wine is an especially bad buy.

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Total faecal proanthocyanidins as intake biomarker? A first exploration

Proanthocyanidins are a class of dietary phenolic compounds, present in foods or beverages such as berries, legumes, wine, cocoa and derived products or nuts. Due to the health benefits associated with proanthocyanidins, it is useful to identify dietary proanthocyanidin biomarkers that can be determined by simple methods. Since increased levels of circulating PA metabolites are associated with increased faecal proanthocyanidin content, this study explores the spectrophotometric measurement of faecal proanthocyanidin content and its use as a biomarker of proanthocyanidin intake.

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