Exploration of the impact of different drying methods on the quality of Gastrodia elata: A study based on drying kinetics and multidimensional quality evaluation

In this study, the drying kinetics and multidimensional quality of Gastrodia elata (GE) obtained through five different drying methods were analyzed. The Page model provided the best fit. Though widely used, hot-air drying (HA-D) showed mediocre performance. Due to strong heat penetration, microwave drying (MV-D) and infrared drying (IR-D) effectively reduced drying time and energy consumption. However, they experienced Maillard and caramelization reactions, resulting in notable cell structure shrinkage, severe browning, pronounced caramel taste, and poor retention of active ingredients. Conversely, freeze-drying (F-D) and vacuum drying (V-D), due to the involvement of low-temperature or vacuum environments, demonstrated optimal performance in preserving microstructure, antioxidant activity, active ingredients, and flavor. However, F-D was time-consuming (1320 min) and had an energy consumption of 2.69 times that of HA-D, limiting its large-scale application. V-D struck the best balance between energy consumption and product quality, making it a highly promising drying method for GE.