Extraction and quantification of main pigments in pesto sauces

Pesto is a widely diffused Italian pasta sauce, whose main ingredient is basil. Since its appearance is a key factor for marketing, the determination of its pigment content is of fundamental interest. To this aim, a method for the determination of pesto pigments by C18-HPLC is proposed. Only β-carotene was determined directly by Vis-spectrophotometry, as a consequence of sample purification over a silica cartridge. The proposed method is reliable allowing, for the first time, an easy determination of chlorophylls, pheophytins, lutein and β-carotene in a complex matrix such as pesto. The results show great differences in pigment composition among the samples, with pheophytins as the main components. Only non-thermally processed product show appreciable chlorophyll content as a consequence of the different production technique. Principal Component Analysis performed on the pigment contents showed great variability among the different samples.