Optimal Steaming Condition of Gastrodia elate Blume (Chunma) using Response Surface Methodology (RSM)

The Chunma requires a simple pre-treatment, due to the inconveniences of preservation, toxicities, and pungencies in intact state. Various steaming conditions were examined to establish the anti-oxidative characteristics of Chunma using the Response Surface Methodology (RSM). Total phenolics and electron-donating ability were optimal at 94.43 and for 42.38 and 41.09 min, respectively. Anti-oxidative (Al) and nitrite-scavenging ability were optimal at for 40 min. Optimal steaming conditions were determined as for min, almost identical to the predicted conditions of , 40 min determined using the superimposed contour map. Anti-oxidative activities (AI) under the optimal conditions were of those determined under predicted conditions, an indication of the high reliability of the calculated values.