## 1 Introduction  
The jujube (_Zizyplus jujuba_ Mill., family Rhamaceae), a traditional food in China, is attractive to consumers due to its rich nutrition, good taste, and potential health benefits [1]. The jujube was harvested from 26,000 hectares of land, and its production was 7.35 million tos in 2022 [2]. Since 2012, there has been an oversupply of jujube on the market because of the excessive production based on large-scale cultivation [3]. Notably, processing is an effective way to reduce post-harvest losses [4]. Among various processed jujube products, dried jujube slices are the most favorable, with the best taste, rich nutritional value, and easy to eat. Additionally, jujube slices provide good economic benefits and broad prospects for development [5]. Dried jujube slices are mostly prepared--including cleaning, coring, and slicing--from naturally dried jujube (about 30% moisture content). The main drying techniques include hot air, microwave, freeze, variable temperature, and pressure differential expansion drying [6]. Microwave drying is a widely applied method in the food industry, with easy operation, low cost, and a short drying cycle. Nowadays, researchers pay more attention to the technical energy consumption, appearance quality, and nutrient retention of different drying processes. [PERSON] et al. [7] investigated the changes in sugars, organic acids, \(\alpha\)-tocopherol, \(\beta\)-carotene, phenolic profiles, total phenolic content (TPC), and antioxidant capacity of juibube with four drying treatments (sun, oven, microwave, and freeze drying) [7]. [PERSON] et al. [8] also compared the structural characterization and antioxidant activity of the polysaccharides of juibube (_Zizyplus jujuba_ Mill., family Rhamaceae) [8]. In contrast, research on the aroma of juibube slices has rarely been reported. Notably, the flavor is essential for the quality and acceptability of dried slices [9; 10]. After microwave drying, the products could have a caramel and sweet roasted flavor similar to toast or coffee aroma under high temperatures and with enough oxygen. The unique caramel and roasted sweet flavor could benefit the products' good flavor [11]. However, unpleasant odor, such as burnt and bitter, could be obtained with an unsuitable drying procedure, which has a bad influence on juibube slices' quality. It is important to study the flavor components and their dynamic characteristics to optimize and control the process parameters during the processing of dried juibube slices.  
Recently, some research regarding the aroma of dried juibue was carried out. [PERSON] et al. [12] used headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME/GC-MS) and electronic nose (e-nose) to study a total of 51 aroma compounds from 10 different varieties of dried juibube [1; 12]. Additionally, [PERSON] investigated the volatile compounds of Chinese juibubes with different drying methods based on metal oxide semiconductor (MOS) e-nose and flash GC e-nose [13]. The above reports illustrated that the drying procedures significantly influenced the variety and amount of volatile compounds and the flavor profile of dried juibube. However, there is a lack of theoretical basis for studying aroma changes in dried juibue during processing. Identifying effective aroma compounds offers a convenient approach to comprehending the sensory alterations, but their research and application in dried juibube slice products are relatively limited.  
This study aimed to identify and measure the aroma-active compounds and their dynamics in dried juibube slices using GC-MS combined with GC-O. Additionally, we wanted to evaluate their contribution to the overall aroma by calculating the odor activity value (OAV) and detection frequency analysis (DFA) and to investigate the relationship between sensory properties and characteristic aromatic active compounds using multivariate analysis of partial least squares regression analysis (PLSR).