Abstract:

Molecular distillation (MD) was used to purify capsicum oleoresin, and three important process parameters such
as distillation temperature, distillation pressure and wiper rolling speed were optimized by response surface methodology
for better separation between capsaicinoids and capsicum red pigment. Individual variables and their interactions on
the response values capsaicinoid concentration and color value were explored according to Box-Behnken design. A
mathematical quadratic polynomial regression equation was established. The optimal process conditions for distillation
temperature, distillation pressure and wiper rolling speed were 144 ℃, 9.5 Pa and 313 r/min, respectively. Under these
conditions, the capsaicinoids concentration was increased to 75.30%, and the color value of capsicum red pigment separated
was 19.84. DPPH radical scavenging assay showed that the capsaicinoids separated had good antioxidant activity.

Key words: capsaicin, molecular distillation, response surface methodology, antioxidant activity