Globe artichoke leaves and floral stems as a source of bioactive compounds

A growing market interest in natural food ingredients and pharmaceuticals has prompted attempts to exploit bioactive compounds, such as antioxidants, present in crop residues. Here, we have characterized the qualitative and quantitative polyphenol profile of globe artichoke waste material (leaves, floral stem), concentrating on clonal materials derived from two Sicilian landrace varieties. A high content of flavones was present in the leaf, and floral stem proved rich in caffeoylquinic acid. Two of the clones (one derived from each of the two landraces) accumulated substantial quantities of caffeoylquinic acids in their stem (respectively 12,659 and 11,835 mg per kg dry matter), and one of them 2978 mg flavones per kg dry matter. A further clone produced as much as 7044 mg flavones per kg dry matter. The predominant caffeoylquinic acids were 5-O-caffeoylquinic and 1,5-O-dicaffeoylquinic in both the leaf and the floral stem, and the predominant luteolins were luteolin-7-O-rutinoside and luteolin-7-O-glucoside. The mean production of polyphenol of the set of 11 clones was 5740 mg per kg dry matter, compared to only 5011 mg in the landrace varieties themselves.

► Crop residues may represent a valuable source of bioactive compounds.
► We characterized the polyphenol profile of globe artichoke waste material.
► Leaf and floral stem were rich in flavones and caffeoylquinic acids.
► The mean polyphenol content of the clones was higher than in the landraces.
► Clonal selection represent a tool for crop enrichment in bioactive compounds.