## 3 Results and Discussion
As shown in Supplementary Table S1, a total of 101 volatile compounds were detected by GC-MS in the five samples, which were categorized into 10 groups: 28 aldehydes, 23 alcohols, 13 esters, 11 heterocyclic compounds, 9 acids, 6 ketones, 5 hydrocarbons, 4 amines, 1 ether, and 1 other (Figure 3b). Notably, the number of volatile compounds fluctuated across samples with different pressure-cooking treatments: 20 min has 63 types, 25 min has 68 types, 30 min has 74 types, 35 min has 76 types, and 40 min has 83 types (as depicted in Figure 3a). Furthermore, to delve deeper into the changes in volatile compounds during the pressure-cooking process, a heatmap of the five samples was constructed, illustrating a discernible divergence in volatile flavor compounds (\(p\) < 0.05) (refer to Figure 4). Figure 2: E-tongue analysis of chicken with _Armillaria mellea_ prepared via pressure cooking for different pressure-cooking times. Radar chart (**a**) and principal component analysis (**b**) of the E-tongue data of chicken with _Armillaria mellea_ that was pressure-cooked for different pressure-cooking times. S40 exhibited the highest volatile compound content, indicating a more intense aroma than other samples. At the same time, S20 and S25 demonstrated lower volatile compound contents, indicating a more prosperous production of volatile compounds with prolonged simmering time. Significant increases in volatile compounds were observed between S25 and S30 and between S35 and S40 (\(p\) < 0.05), possibly attributed to the robust Maillard reaction occurring at 25-30 min, and intensified again at 35-40 min, thereby generating a plethora of new volatile compounds. Moreover, the number of identical types of volatile compounds varied across samples, implying distinct aroma profiles (refer to Figure 5). Most volatile compounds are on the rise overall, and this phenomenon may be elucidated by the emission of inherent volatile flavor compounds from chicken and _Armillaria mellae_ at the onset of pressure cooking, followed by the commencement of the Maillard reaction as pressure cooking progressed, leading to the generation of new volatile compounds. Notably, aldehydes and alcohols emerged as the most abundant compounds, pivotal in flavor changes. Previous studies have also highlighted aldehydes' prevalence as the most abundant compounds in cooked meat [29]. The abundance of aldehydes in S40 indicates that prolonged pressure-cooking time increases aldehyde levels through lipid degradation. Concurrently, fatty alcohols resulting from lipids' oxidative decomposition also influence flavor considerably. Furthermore, the presence of several esters, heterocyclic compounds, acids derived from aldehydes' oxidation, and ketones from alcohol oxidation was observed, further contributing to flavor complexity. Consistent with E-nose results, the volatile compound content of chicken with _Armillaria mellae_ prepared via pressure cooking was observed with increasing pressure-cooking time (\(p\) < 0.05), particularly at 35-40 min. This underscores the continuous Maillard reaction between chicken with _Armillaria mellae_ during the pressure-cooking process, resulting in protein degradation, lipid oxidative degradation, and augmentation in the number and content of volatile compounds, thereby imparting a distinctive and detectable aroma. Figure 3: Analysis of volatile compounds, using SPME-GC-MS, in chicken with _Armillaria mellae_ prepared via pressure cooking. (**a**) Number of volatile compounds detected among different groups. (**b**) Relative content of volatile flavor compounds across each group. Figure 4: Heat map illustrating clustering results of volatile compound concentrations in chicken with _Armillaria mellea_ prepared via pressure cooking for various pressure-cooking times. The color of the squares in the chart indicates the number of volatile compounds in chicken with _Armillaria mellea_ prepared via pressure cooking. The color ranges from blue to red, with the relative content increasing from low (blue) to high (red).