Abstract:

Objective: To investigate the separation and purification of red pigment from the bracts of Zingiber mioga Rosc.
and the preparation of red pigment powder by spray drying. Methods: Comparison of ten kinds of macroporous resin was
carried out for the static and dynamic adsorption and desorption of red pigment. The purified red pigment was vacuumconcentrated
before spray drying. Results: LSA-21 macroporous resin was found to be the best sorbent for the purification
of red pigment. The best results were obtained when the sample (3.85 mg/mL, pH 5.0) was loaded at a flow rate of 2 BV/h
and the adsorbed red pigment was eluted with acidified distilled water at a flow rate of 3 BV/h. The purified pigment solution
was added with 2% soluble starch and adjusted to a soluble solid content of 12%-14% prior to spray drying at a feeding
rate of 3.0-4.0 kg/h, an air inlet temperature of 174-177 ℃, an air outlet temperature of 65-71 ℃, an exhaust velocity of
0.34–0.38 m3/min, and an atomization pressure of 100 kPa. The resulting powder consisted of three monomers as detected by
high performance liquid chromatography (HPLC) and thin layer chromatograph (TLC). Conclusion: LSA-21 macroporous
adsorption resin is applicable for separation and purification of red pigment from Zingiber mioga Rosc. and the optimized
spray drying conditions are suitable for industrial production of red pigment powder from Zingiber mioga Rosc.

Key words: spray drying, macroporous resin, red pigment, TLC, HPLC