Residues of ethylenethiourea (ETU) in grapes and wine were determined by capillary gas chromatography and paper chromatography, without a cleanup step, and after derivatization to S-benzyl-ETU. The detection limit was 0.0002 mg/kg for flame ionization detection, 0.008 mg/kg for paper chromatography with photodensitometric evaluation of the detected spot. Results were compared with a generally used GC method specifying electron capture detection of trifluoroacetylated S-benzyl-ETU. The recoveries of ETU in grapes and wine at different concentration levels were determined. ETU residues were determined in treated grapes but no residues were detected in wine.
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Plant Dis
January 2025
University of California Davis, Cooperative Extension, Napa, California, United States;
The timely detection of viral pathogens in vineyards is a critical aspect of management. Diagnostic methods can be labor-intensive and may require specialized training or facilities. The emergence of artificial intelligence (AI) has the potential to provide innovative solutions for disease detection but requires a significant volume of high-quality data as input.
View Article and Find Full Text PDFFront Plant Sci
January 2025
Division of Ecology and Evolution, Research School Research of Biology, The Australian National University, Acton, ACT, Australia.
Food Chem
December 2024
Wine Science Programme, School of Chemical Sciences, The University of Auckland | Waipapa Taumata Rau, 23 Symonds Street, Auckland 1010, New Zealand. Electronic address:
Grape marc, a by-product of winemaking, is a rich source of bioactive compounds, yet efficient extraction methods suitable for industrial application remain underexplored. This study presents an integrated, three-stage approach to optimise the extraction of anthocyanins, phenolics, and tannins from Merlot grape marc. In the first stage, 12 solvents were evaluated using conventional solvent extraction, with 50 % ethanol (EtOH) acidified with hydrochloric acid (HCl) achieving the highest anthocyanin recovery after eight extraction cycles (0.
View Article and Find Full Text PDFPharmaceutics
January 2025
Faculty of Pharmacy, Medical University of Sofia, 1000 Sofia, Bulgaria.
Resveratrol is a natural polyphenol (stilbenoid), which can be found in grape skin, red wine, blueberries, peanuts and others. The biological properties of resveratrol, in particular antioxidant, anti-inflammatory, anticancer, estrogenic, vasorelaxant and cardioprotective activity, are the main reason for its importance in medicine and pharmacy. Despite all of its advantages, however, there are many problems related to this polyphenolic substance, such as low stability, water insolubility, poor bioavailability and fast metabolism.
View Article and Find Full Text PDFPlants (Basel)
January 2025
National Wine Agency of Georgia, Tbilisi 0159, Georgia.
Repeated expeditions across various regions of Georgia in the early 2000s led to the identification of 434 wild grapevine individuals ( L. subsp. (C.
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