## 4 Conclusions  
Through GC-MS detection combined with OAV and DFA analysis methods, we identified the 21 most significant aroma-active compounds in jujube slices, including 17 compounds with OAVs \(\geq\) 1, 15 compounds with DFs \(\geq\) 5, and 11 compounds with both OAVs \(\geq\) 1 and DFs \(\geq\) 5, such as caramel-like 4-cyclopentene-1,3-dione and bitter-like 5-methyl-2(5H)-furanone. Simultaneously, some new compounds were found to possess aroma activity in jujube, namely 5-ethyldihydro-2(3H)-furanone,5-methyl-2(5H)-furanone, 3-Hydroxy-2-methyl-4H-pyran-4-one, 2,5-Dimethyl-4-hydroxy-3(2H)-furanone, and 4-Cyclopentene-1,3-dione. Furthermore, the PLR analysis of 21 aroma-active compounds and sensory evaluation results showed that 2,3-butanedione and acetoin were significantly and positively correlated with the roasted sweet attribute, while \(\gamma\)-butylrolactone, 4-cyclopentene-1, 3-dione, and 2,5-dimethyl-4-hydroxy-3(2H)-furanone provided an intense caramel flavor. Moreover, Ethanone, 1-(2-furanyl)- and 5-methyl-2(5H)-furanone were the primary sources of the bitter taste. Notably, the burnt taste in jujube slices was found to be mainly caused by 3-Hydroxy-2-methyl-4H-pyran-4-one, while 2-Furanmethanol and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-Pyran-4-one were identified as the primary sources of both burnt and bitter flavors.  
Figure 5: Regression coefficients and significance indications for sensory attributes by PLRR1. (**a**) Jujube factor; (**b**) Caramel factor; (**c**) Roasted sweet factor; (**d**) Bitter factor; (**e**) Burnt factor. Gray columns are the key compounds identified by OAV and DFA.  
Among the 21 flavor compounds, 5-methyl-2(5H)-furanone, 4H-Pyran-4-one, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-Pyran-4-one were undetected in the unheated sample (B1). 5-methyl-2(5H)-furanone was also not detected in the sample microwaved for 1 min (B2). Compounds such as 1-(2-furanyl)-ethanoneone, 5-methyl-2(5H)-furanone, 3-Hydroxy-2-methyl-4H-pyran-4-one, 2-furanmethanol, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one, which exhibit burnt and bitter flavor, gradually increased in content with the increase in microwave time. The contents of compounds (2,3-butanedione, acetoin, \(\gamma\)-butyrolactone, 4-cyclopentene-1,3-dione, and 2,5-dimethyl-4-hydroxy-3(2H)-furanone) exhibiting roasted sweet and caramel flavors initially increased, then decreased, and reached their highest levels at 2.5 min (B4). Importantly, these conclusions could contribute to understanding the material basis of dried jujube slices' aroma and their change regularities and provide a theoretical basis for improving the aroma quality and regulating peculiar flavor to produce high-quality jujube slices.  
Conceptualization, Y.S. and M.T.; methodology, M.T.; software, S.P. and M.T.; validation, X.Z.; formal analysis, X.L.; investigation, X.Y.; resources, M.W.; data curation, S.P. and W.D.; writing--original draft preparation, S.P. and X.Y.; writing--review and editing, X.L.; project administration, M.W.; funding acquisition, Y.S. All authors have read and agreed to the published version of the manuscript.  
This research was funded by National Key Research and development project, Taishan Scholar Youth Expert Project, tsqn202211273.  
The data used to support the findings of this study can be made available by the corresponding author upon request.  
The authors declare no conflict of interest.