Extraction, purification of bioactive trans-resveratrol from grape pomace as factory waste, and enhancement of bioavailability through encapsulation technology

Trans-Resveratrol is a key phenolic compound with known health benefits but suffers from low bioavailability and instability. Its encapsulation is challenging due to its polarity. In this study, trans-resveratrol was isolated, purified, and structurally characterized from grape pomace, a wine industry by-product, using LC-MS/MS, HPLC-PDA, and 1H NMR. To improve its stability and solubility, nanoencapsulation was carried out with lecithin via lyophilization. The resulting nanoparticles had sizes below 160 nm, a PDI under 0.5, and high colloidal stability as shown by zeta potential analysis. In vitro release tests in simulated gastric and intestinal fluids revealed enhanced release for the lecithin-encapsulated formulation, achieving up to 80 % in intestinal conditions, unlike free trans-resveratrol. These findings suggest that grape pomace is a valuable source of bioactive compounds and that lecithin-based nanoencapsulation offers a promising strategy to enhance the delivery and bioavailability of trans-resveratrol.