Abstract:The quality of fresh Gastrodia elata Blume (G. elata) processed and dried by using different methods was compared to clarify the effects of different drying methods on the quality of dried G. elata. Specifically, the G. elata samples were unprocessed (NGB) or steam-processed (PGB) before undergoing natural air drying, hot air drying, vacuum freeze drying (CFD), or vacuum microwave drying (VMD). The quality of the dried samples was then evaluated in terms of microstructure, contents of eight functional components (such as gastrodin and p-hydroxybenzyl alcohol), and in vitro antioxidant and antihypertensive activity. The results showed that the processing and drying methods significantly impacted the morphology and functional component contents of dried G. elata. The PGB-CFD group had the highest total functional component content of 42.71 mg/g, followed by the NGB-VMD group, at 30.98 mg/g. The NGB-CFD group exhibited the highest antioxidant capacity, with the total antioxidant capacity, DPPH free radical-scavenging capacity, and ABTS+ free radical-scavenging capacity reaching 68.54%, 50.86%, and 41.05%, respectively. The PGB-CFD group showed the highest ACE inhibition rate of 82.50%. In conclusion, the NGB-CFD method is the optimal drying method for G. elata slices. This study provides reference methods and basic data for further precise processing of fresh G. elata.
