## 4 Conclusions  
This study examined the effect of different drying methods on the flavor quality of oysters. The drying method was found to significantly affect the flavor characteristics of oysters. HAD strengthened the umami attributes of dried oysters, and VFD was superior in retaining umami nucleotides (AMP, IMP, GMP), whereas SD had the most prominent bitter and sweet taste. Compared with raw oysters, hot-digestion dry processing (HAD, VD, and NSD) enhanced the richness of dried oyster odor, imparting dried oysters with fruity, fatty, and roasted aromas. Moreover, glutamic acid, glycine, betaine, IMP, pentanal, ethyl heptanoate, (E, Z)-2,4-nonadienal, 1-octen-3-one, 2-hexenal, 2-octenal, hexanal, and decanal were defined as markers to distinguish among the drying methods. These results can serve as a basis for the standardization of dried-oyster production. Nevertheless, it is unclear how the characteristic flavor substances of dried oysters are produced. This involves a complex system of biochemical reactions, and elucidating the pathways of protein degradation, lipid thermal oxidation, and Maillard reactions during oyster drying in future studies will be important for improving the quality of dried aquatic products.  
Figure 8: PLS-DA score plots (**A**) and (**C**) VIP scores obtained by modeling taste substances in dried oysters under different drying conditions; PLS-DA score plots (**B**) and (**D**) VIP scores obtained by modeling volatile substances in dried oysters under different drying conditions. CK: blanched oysters; VFD: vacuum freeze drying; VD: vacuum drying; NSD: natural sun-drying; HAD: hot air drying.  
**Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/foods12112136/s1](https://www.mdpi.com/article/10.3390/foods12112136/s1)]([https://www.mdpi.com/article/10.3390/foods12112136/s1](https://www.mdpi.com/article/10.3390/foods12112136/s1)), Table S1: Analysis of FAAs and flavor nucleotides in dried oysters under different drying conditions (mg/100 g, dry weight); Table S2: Taste attributes (+pleasant, \(-\)unpleasant) and TAVs in dried oysters under different drying conditions; Table S3: identification and quantification of volatile compounds in dried oysters under different drying conditions (ug/100 g, dry weight); Table S4: Odor thresholds and aroma-active compounds in dried oysters under different drying conditions [41]; Table S5: Peak values of standards, regression equations, standard curve coefficients.  
**Author Contributions:** Z.W.: visualization, methodology, validation, investigation, writing--original draft. H.L. ([PERSON]): investigation, methodology, resources, writing--review. W.C.: conceptualization, investigation, resources, writing--review and editing, project administration, funding acquisition. Z.C.: conceptualization, writing--review and editing. J.G.: investigation, resources. H.Z.: writing--review and editing. H.L. ([PERSON]): resources. X.Q.: writing--review and editing. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was supported by the Science and Technology Plan Project of Zhanjiang City (2022A05038), the \"First Class\" Provincial Financial Special Fund Project of Guangdong Ocean University (231419014), and the earmarked fund for CARS (CARS-49).  
**Data Availability Statement:** The datasets generated for this study are available on request to the corresponding author.  
**Conflicts of Interest:** The authors declare no conflict of interest.