Evaluation of cardoon seeds presscake for animal feeding

The research of new formulations of innovative animal feed highly healthy through the use of biologically active compounds, derived from food processing wastes and crop residues from the production of agroenergy, is increasing. The cardoon (Cynara cardunculus L.) seeds presscake is a by-product of the biorefinery that could be used in animal nutrition, due to its content of protein, fibre and lipid component remaining from the oil extraction. Furthermore cardoon contains biologically active compounds, such ortho-diphenols, flavonoids and flavolignane, all substances useful to enhance animal feed. This study is based on the characterization of presscake residual, obtained by mechanical cold pressing of the cardoon seeds for oil, for the development of animal feed. For this purpose a new line of domestic cardoon is used, Cynara cardunculus L. var. altilis DC, selected for biorefinery. Using a pilot plant, 1044 kg of oil and 3456 kg of presscake was obtained through pressing of 4500 kg of cardoon seed. Chemical composition of whole cardoon seed and presscake was studied. The whole cardoon seed contained 28.5% of fat, 22.0% of fibre, 16.7% of protein, 28.5% of nitrogen-free extracts and the presscake contained 6.9% of fat, 28.1% of fibre, 21.3% of protein and 38.2% of nitrogen-free extracts. The determination of amino acids, including sulfur amino acids and tryptophan, was performed on the protein extract of presscake (18.5% total amino acids, 0.6% sulfur amino acids, 0.3% tryptophan). Additionally on the seed presscake, the phenolic acids determination (chlorogenic acid, caffeic acid, catechin) and the characterization of major fatty acids with 10.3% palmitic, 2.9% stearic, 25.5% oleic and 59.6% linoleic, was carried out. Results showed that the cardoon seed presscake for its chemical composition and the content of phenolic compounds, 12000 mg kg-1 DM, has high nutritive and energy value, essential parameters for a good animal feed.