Chemical composition of cardoon (Cynara cardunculus L. var. altilis) petioles as affected by plant growth stage

In the present study petioles were collected from cultivated cardoon (Cynara cardunculus L. var altilis) plants in central Greece at sixteen harvest dates (samples P1-P16) and nine growth stages (principal growth stages (PGS) 1-9). The main objective of this study was to study the influence of petioles' growth cycle on their chemical composition. The lipidic content, fatty acids, free sugars, organic acids, and tocopherol composition were analyzed. A total of 27 fatty acids were identified, being the palmitic acid (C16:0, 12.42-50%) the most abundant, except for samples P4 and P5 where linoleic acid revealed the highest relative abundance (C18:2n6c, 46.5 and 39.05%, respectively). The α-, β-, and γ-tocopherols were the identified isoforms of vitamin E, with sample P1 recording the highest tocopherol content. The detected organic acids were oxalic, quinic, malic, citric, and fumaric acids with the highest content being observed in sample P1. Sucrose was the major sugar in all the analyzed samples, followed by fructose, glucose, trehalose, and raffinose. The obtained results allowed us to characterize the chemical composition of cardoon petioles throughout its growth cycle and, consequently, to valorize the species through the exploitation of underutilized plant tissues.