The three-dimensional structures of 5 procyanidin dimers have been determined in a hydro-alcoholic medium and in water using 2D NMR and molecular mechanics. They are made from monomers of catechin (CAT) and epicatechin (EPI)-B1: EPI-CAT, B2: EPI-EPI, B3: CAT-CAT, B4: CAT-EPI and B2g: EPI-EPI-3-O-gallate. These tannins exist in two conformations that are in slow exchange in the NMR timescale (s), one is compact and the other extended. The compact form is found to dominate (76-98%) when the dimer is made of at least one CAT monomer (B1, B3, B4). Both forms are found in even proportions only in the case of procyanidin B2. The latter tannin can be converted into a dominant compact form when the lower EPI unit is galloylated. The finding of a predominant compact form for procyanidin dimers is discussed in relation with tannin-saliva protein interactions that are of importance for the wine-tasting/making processes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/mrc.1867 | DOI Listing |
Sci Rep
January 2025
Department of Fruit, Vegetable and Plant Nutraceutical Technology, The Faculty of Biotechnology and Food Science, Wrocław University of Environmental and Life Sciences, 37 Chełmońskiego Str, 51-630, Wrocław, Poland.
Drying plant raw materials using modern techniques or combined methods is currently one of the main trends in food technology, which combines process optimization in line with the principles of sustainable development while maintaining high product quality. Therefore, this study aims to be innovative, assessing the possibility of using sublimation techniques, convective drying (CD) at different temperatures (50 °C, 60 °C, 70 °C), vaccum microwave drying (VMD) at different power levels (120 W, 240 W, 360 W, and 360/120 W), and combining these two techniques- CD-VMD (50 °C/120 W, 60 °C/120 W, 70 °C/120 W) in the production of peach snacks. The qualitative analysis of the tested dried peaches showed that the content of polyphenols was dominated by polymers of procyanidins (82.
View Article and Find Full Text PDFPlant Foods Hum Nutr
January 2025
Departamento de Investigación y Posgrado en Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Qro., 76010, México.
Grape pomace (GP) is a by-product rich in phytochemicals, including extractable polyphenols (EPPs) and non-extractable polyphenols (NEPPs), which have distinct metabolic fates that may affect their biological activities. The benefits of GP have been reported in relation to obesity and its comorbidities, particularly when administered preventively focusing on EPPs. Therefore, the aim of this study was to investigate the effects of EPPs and NEPPs from GP as a treatment for obesity and its associated metabolic alterations.
View Article and Find Full Text PDFMolecules
December 2024
Department of Molecular Food Chemistry and Development, Institute of Food and One Health, Leibniz University Hannover, 30167 Hannover, Germany.
This study systematically investigated the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical induced oxidation of all dimeric C4-C8 linked B-type procyanidins (PCs) B1-B4 to maximise the formation of the oxidation products using a Design of Experiments (DoE) approach. The C4-C8 linked B1 and B2 formed the A1 () and A2 () (/ 575 [M-H]) with an ether bridge between C2u-O-C7t as expected. Interestingly, the oxidation of the C4-C8 linked dimers B3 and B4 yielded for each two main oxidation products with / 575 [M-H].
View Article and Find Full Text PDFJ Pharm Anal
November 2024
National Key Laboratory of Chinese Medicine Modernization, Tianjin University of Traditional Chinese Medicine, Tianjin, 301617, China.
In this study, 34 deep eutectic solvents (DESs) were successfully prepared for the extraction of proanthocyanidin from Rhodiolae Crenulatae Radix et Rhizomes. The extraction process was optimized using single factor exploration and Box-Behnken design-response surface analysis. The extraction rate was significantly improved when the molar ratio of choline chloride to 1,3-propanediol was 1:3.
View Article and Find Full Text PDFFoods
December 2024
Department of Food Engineering, Faculty of Agriculture, Cukurova University, 01330 Adana, Türkiye.
Consumers' demand for foods with health benefits and different tastes is on an increasing trend. Juniper berries ("andiz" in Turkish) are the fruits of perennial, aromatic, and resinous trees. In this study, quality properties of herbal coffee samples obtained from juniper berries roasted at three different temperatures (120, 160, and 200 °C) and four different durations (10, 25, 32.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!