In order to avoid remain of toxic solvent in the red colorant, a
series of new technologies had been investigated for extraction
of red pigment from dried red peppers. Amaya Guerra, Sernma
Sldivar, Cadenas, & Nevera Munoz (1997) compared the effect
of several solvents (ethanol, acetone, ethyl acetate and hexane)
on extraction of red pigment and found that the amount of
pigment extracted increases with the polarity of the solvent. And
ethanol gave the highest amount of oleoresin with 82% of capsaicinoids
and 74% of carotenoids. Enzyme-assistant extraction
(EAE) was also investigated for selective extraction of capsaicinoids
and carotenoids with different concentration of
aqueous ethanol , but the oleoresin
obtained was actually a mixture of capsaicinoids and red
pigment. Supercritical carbon dioxide extraction (SCDE) was reported
with a high yield of carotenoids without any remain of
organic solvent . However, SCDE is so expensive that it is not realistic
in industrial production of pepper colorants. And more importantly,
dry red peppers (DRPs) as materials were still used by the
above-mentioned methods.