# Effect of Different Drying Methods on the Quality of _Oudemansiella raphanipes_
## 4 Conclusions  
This study showed that the sensory and nutritional differences between _O. raphanipes_ obtained using three different drying methods were more significant. Dried products of _O. raphanipes_ treated by vacuum freeze drying had the highest rehydration rate and were closer in appearance quality to the fresh samples, but they were lower than hot air drying in terms of flavor scores, which was consistent with the results of the subsequent volatiles assay. The microstructure of _O. raphanipes_ dried by hot air drying and infrared radiation was obviously changed, while vacuum freeze drying could maintain the porous spatial three-dimensional structure of the mushroom. Alkanes are the main components of the overall volatile compounds, followed by alcohols and esters. The relative content of vacuum freeze-dried volatile substances is higher because some volatile substances are easily degraded or decomposed during heating and infrared radiation treatment, and vacuum freeze drying can reduce the occurrence of this reaction. PS-V had the highest yield among the polysaccharides mentioned in the three dried products, and the structures of the three were basically the same, but there were some differences in the chemical compositions: PS-V could be seen as a reticulated structure accompanied by globular protrusions under high magnification, suggesting that there was a large number of internal cavities, whereas PS-H and PS-I showed a lamellar structure in general. The antioxidant activities of the three polysaccharides against DPPH and -OH as well as the inhibitory activities against \(\alpha\)-glucosidase and \(\alpha\)-amylase, although all of them were reduced to varying degrees, PS-V exhibited stronger biological activities compared to PS-H and PS-I. In conclusion, if the  
Figure 7: Effect of different drying methods on enzyme inhibitory activity of polysaccharides, (A) \(\alpha\)-glucosidase and (B) \(\alpha\)-amylase. Data are expressed as the mean \(\pm\) standard deviation (\(n=3\)). main consideration is the appearance quality and nutrient retention of _O. raphanipes_ after drying, vacuum freeze drying is the best; however, if considering the cost and energy consumption of the product drying process, hot air drying is recommended because it is simple to operate, short in time, low in energy consumption, and also has a high flavor score. Infrared radiation drying is in between the two and can be chosen differently according to needs. This provides a theoretical basis for the selection of the drying method of _O. raphanipes_ and could be used to guide the practical processing of _O. raphanipes_. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods13071087/s1](https://www.mdpi.com/article/10.3390/foods13071087/s1)]([https://www.mdpi.com/article/10.3390/foods13071087/s1](https://www.mdpi.com/article/10.3390/foods13071087/s1)), Figure S1: Total Ion Chromatogram of volatile compounds in _O. raphanipes_ dried using different methods. S.H. : Conceptualization, methodology, investigation, writing--original draft. D.Z. : Software. D.Y. : Methodology. H.L. : Date curation. Y.X. : Formal analysis. W.W.: Formal analysis. R.L. : Investigation. C.F. : Resources, formal analysis. J.M. : conceptualization, methodology. L.X. : resources. Y.C. : formal analysis, visualization. M.C. : Resources, data curation. X.G. : Supervision, writing--review and editing. All authors have read and agreed to the published version of the manuscript. This research was funded by Doctoral Science Foundation of Shanxi Agricultural University [2017/Y33]; the Shanxi Province Modem Agricultural Industrial Technology System Construction Special Fund [2023 CY]STX09]; the Collaborative Innovation Center for Quality Improvement and Efficiency of Edible Mushrooms on Loess Plateau [2023 CXYRH-039]; the Edible fungi Key Team of Science and Technology Innovation of Shanxi Province [201805D131009]. Not applicable.