Study on mechanism of forming red-skin and dark-green-skin of Panax quinquefolius / 中草药

ABSTRACT

Object To study the causes for the occurrence of red skin and dark green skin of Panax quinquefolius L. during processing and its mechanism. Methods To observe the phenomena and analyze the result which simulated the processing condition of P. quinquefolius based on its components. Results The cross section of P. quinquefolius began to appear light red at 40 ℃, lasting 72 h. Whereas the time of browning was shortened with the temperature rising. The cross section of P. quinquefolius turned green while dipping in solution of Fe 3+ ion of 0 01 mol/L for 25 min. The time of turning green was shortened with the increasing concentration of Fe 2+ , Fe 3+ solution. Conclusion The results show that red skin of P. quinquefolius was caused by the Maillard reaction while drying at the excessive higher temperature. Whereas the complex reaction between phenolic substances in P. quinquefolius and metal ions during processing might result in dark green skin of P. quinquefolius. This expounds the mechanism of red skin and dark green skin turning during the P. quinquefolius processing in the theory.