Various Extraction Methods for Obtaining Stilbenes from Grape Cane of Vitis vinifera L.

Abstract

Grape cane, leaves and grape marc are waste products from viticulture, which can be used to obtain secondary stilbene derivatives with high antioxidant value. The presented work compares several extraction methods: maceration at laboratory temperature, extraction at elevated temperature, fluidized-bed extraction, Soxhlet extraction, microwave-assisted extraction, and accelerated solvent extraction. To obtain trans-resveratrol, trans-ε-viniferin and r2-viniferin from grape cane of the V. vinifera variety Cabernet Moravia, various conditions were studied: different solvents, using powdered versus cut cane material, different extraction times, and one-step or multiple extractions. The largest concentrations found were 6030 ± 680 µg/g dry weight (d.w.) for trans-resveratrol, 2260 ± 90 µg/g d.w. for trans-ε-viniferin, and 510 ± 40 µg/g d.w. for r2-viniferin. The highest amounts of stilbenes (8500 ± 1100 µg/g d.w.) were obtained using accelerated solvent extraction in methanol.

Role of Resveratrol in Regulating Cutaneous Functions

“…Similarly, heating highbush Michigan blueberries at 190°C for 18 min reduced trans-resveratrol by over 40% as compared to raw blueberries [55]. Moreover, methanol extraction of grapes yields resveratrol as much as two times of acetone extraction [70]. In summary, plants and fruits contain a fair amount of resveratrol.…”

Varietal Distributions of Stilbenes in Grape Cane of Vitis vinifera L.

“…In the study published by Lambert et al (2013) drying occurred at the temperature of 40 °C during 15 days period but in our case there was immediately freezing and lyophilisation; in our previous study (Soural et. al., 2015) drying took place at the room temperature (22 °C approximately) for 2.5 months in darkness.…”

“…All the supernatants were combined and the final volume of each supernatant mixture was adjusted to make 5 ml. A similar process of extraction was done in the previous study with the Cabernet Moravia variety, when extraction yields were comparable with additional extraction steps (Soural et al, 2015).…”

“…Finally, the method of quantification was validated in terms of linearity, limits of detection, and repeatability (Tříska et al, 2012(Tříska et al, , 2013. Identifications of stilbenes (trans-resveratrol, transe-viniferin and r2-viniferin) were done previously by HRMS (High Resolution Mass Spectrometr) and H-NMR (Nuclear Magnetic Resonance) as presented by Soural et al (2015). contents of stilbene over time and higher temperature of storing.…”

“…We studied distribution of three types of stilbenes in different varieties of Vitis vinifera L. Extraction at 50 °C for more than two hours has a very high yield as observed in the previous study (Soural et al, 2015). Using higher temperature to increase the efficiency of extraction can destroy stilbenes.…”