... powder 2. Polyphenol, procyanidin, Resveratrol. 3. UV/HPLC Test 4. GMP Factory 5. Quick Shipment Name: Grape Seed Extract, Grape Skin Extract, Wild Grape Extract PowderPlant Origin: Vitis ... UV, Folin Assay and HPLC Grape Skin Extract1. Anthocyanidins(OPC) 5%, 25% 2. Polyphenols 25%, 30% 3. Resveratrol 5% Grape seed extract may have other possible anti ...