Drying Process of Wuhong Gastrodia

To explore the effect of drying process on the quality of Wuhong Gastrodia elata,Gastrodia stem and Gastrodia slice were respectively dried at 45~70 ℃.The drying rates of the two processing methods at different temperatures were compared,and the quality indexes of color,chemical composition,antioxidant effect and polysaccharide content of dried samples were also studied. The a^*,b^* values and gastrodin contents increased with the increasing drying temperature in both Gastrodia stems and Gastrodia slices. Compared with Gastrodia stems,slice processing was more benefic to the release of gastrodin,hydroxybenzyl alcohol and polysaccharides,and the antioxidant function(DPPH free radical scavenging ability,FRAP value and ABTS free radical scavenging ability)of Gastrodia slice extract was enhanced in accordance.The drying efficiency of Gastrodia slices was much higher than that of Gastrodia stem. Therefore,slice processing is more suitbale for the the drying of Gastrodia elata,and Gastrodia elata sliced to 2~3 mm and drying for 4 h under 70 ℃ is the best drying process in this study.