EXTRACTION AND CHROMATOGRAPHIC IDENTIFICATION OF CAROTENOIDS OF RED PEPPER

The aim of this investigation was to extract the pigments from
red pepper and to identify its components. Dried red pepper extracts
showed higher absorption intensity than those of the fresh red pepper.
The HPLC-chromatogram shows that the red pepper pigments consist
of about 20 fractions, which have been identified according to their
absorption spectrums. The major component of red pepper pigments
in the fresh sample was the red color of capxanthin (52.31 %). The
other components in the extract were zeaxanthin, capsorubin,
violaxanthin, cryptoxanthin and lutein. Drying of red pepper samples
facilitated the extraction of more pigment components such as
anthraxanthin, capsorubin esters as well as α and β- carotenes. The
optical density of the red pepper extracts increased with increasing the
extraction time and temperatures in solid: solvent ratio of 1:2,
compared with the 1:4 ratio. The calculated rate constant κ (min-1)
values for the pigment extraction were increased with increasing
temperature in both untreated and steam-blanched dried red pepper,
which ranging 0.013 to 0.023 min-1 in the untreated extracts (1:2).
Also, the activation energy values (of the extraction process) ranged
between 23.1 to 58.9 KJ/mol for untreated and steam-blanched dried
samples.
The color parameters of the ethanolic extracts, (a) and chroma
values were increased while (b) and hue values were decreased with
the progress of extraction time and with increasing extraction
temperature. The equilibrium moisture contents of red pepper powder
were higher in the untreated red pepper compared with the steam-
blanched samples, which varied between 0.094 to 0.455 g H 0/g DM2
EXTRACTION AND CHROMATOGRAPHIC IDENTIFICATION144
in the aw range of 0.11 to 0.85, respectively. Halsey equation found to
be the best isotherms equation to fit the experimental data for a wide
range of water activity (0.11-0.85).