The present research aimed to study the proximate composition, fatty acid profile, antiox-idant activity, total phenolic and N-trans-Caffeoyltyramine content of three distinct varieties of hemp seeds (Carmaenecta, Enectaliana and Enectarol, grown in a Mediterranean area (Central Italy), as feed in the diet of farm animals. Proximate composition was determined using the official methods of analyses; the fatty acid profile was determined by gas chromatography, total phenolic content (TPC) and the scavenging activity (DPPH• and ABTS•+) by the colorimetric method, and N-trans-Caffeoyltyramine content by HPLC analysis. The hemp seed Enectarol showed the highest total lipid content and the best antioxidant activity with the highest TPC, N-trans-Caffeoyltyramine content, and ABTS•+, and the lowest peroxidation index and DPPH•; Carmaenecta showed the best fatty acid profile and nutritional indices (atherogenic and thrombogenic indices and hypocholesterolemic/hypercholesterolemic ratio), and Enectaliana showed the highest crude protein and dietary fiber content. The differences observed in the chemical composition, fatty acid profile and antioxidant activity are because of the varieties, considering that all other growing conditions were the same. The results obtained suggest that hemp seed can be used as a source of lipid and protein in animal diets due to their valuable antioxidant activity and as a rich source of essential fatty acids.
Keywords: animal feed; antioxidant activity; fatty acids; hemp seeds; phenolic compounds.