... Test 4. GMP Factory 5. Quick Shipment Name: Grape Seed Extract, Grape Skin Extract, Wild Grape Extract PowderPlant Origin: Vitis vinifera LUsed Part: Seed ... . atechin, epicatechin, ECG, etc. By UV, Folin Assay and HPLC Grape Skin Extract1. Anthocyanidins(OPC) 5%, 25% 2. Polyphenols 25%, 30% 3 ...