Abstract:

In order to improve the efficiency of pigment extraction from corn gluten powder, the effects and underlying
mechanism of extrusion pretreatment on the extraction rate of yellow pigment from corn gluten powder were studied, and
components of the pigment were analyzed. The results indicated that pigment yield increased obviously after extrusion. The
optimal extrusion conditions were found as follows: moisture content, 18%; extruder barrel temperature, 150 ℃; and screw
speed, 160 r/min. Under these conditions, the pigment yield reached (59.03 ± 1.86) mg/g, which was 149.70% higher than
that from non-extruded corn gluten powder. The microstructure observed by scanning electron microscope (SEM) showed
that the external morphology and internal structure of corn gluten powder were destroyed and significantly changed after
extrusion, leading to increased yield of yellow pigment. The high performance liquid chromatographic (HPLC) profile of the
pigment showed that the main components consisted of zeaxanthin, lutein and other carotenoids.

Key words: extrusion pretreatment, corn gluten powder, yellow pigment, extraction, microstructure, component analysis