Variation in the content of the main guaianolides and sugars in Cichorium intybus var. “Rosso di Chioggia” selections during cultivation

Cichorium intybus var. “Rosso di Chioggia” is a chicory variety cultivated predominantly in Northeastern Italy and highly appreciated for its bitter taste. The commercial portion of the plant, used as food, comprises the innermost leaves (head) of plants harvested during the first year of growth; the outermost leaves and the roots are considered wastes. Three selections belonging to this variety have been analyzed for guaianolide and sugar contents and compared with the commercial product (head), roots and outermost leaves. The qualitative and quantitative evaluations of both classes of compounds were achieved by densitometric HPTLC. The analytical data showed a high variability during the stages of growth, both among the parts of the plant and among the three selections of chicory considered. With particular reference to the heads, a sensory bitterness evaluation method was set up in order to find a correlation between the analytical data and the bitter taste.