Qualitative and semiquantitative analysis of dried fruits and seasoning products of paprika using photoacoustic spectroscopy

Photoacoustic spectroscopy was applied in the ultraviolet and visible regions to investigate some qualitative features of powdered paprika prepared from ripe fruits differing in color as well as of two commercial paprika spices. Absorption maxima were attributed to different pigment absorptions, especially to capsaicin and the carotenoids in all fruits and chlorophyll in the powdered fruits of green paprika. It could be shown that the highest pigment content of the commercial products is correlated to a definite particle size range of the powder. Investigations in the near-infrared region on a commercial seasoning product revealed that the intensity of an unspecific absorption in this region can be used to obtain semiquantitative information about total pigment composition. Keywords: Paprika; semiquantitative food analysis; ultraviolet, visible, near-infrared photoacoustic spectroscopy; natural pigments