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.