## 3 Results  
### Characterisation of the Volatile Composition  
The total ion chromatogram (TIC) of ACC and AMC is shown in Figure 1. A total of 114 VOCs were found and identified in the honeycombs: 11 aldehydes, 13 hydrocarbons, 11 ketones, 26 esters, 38 terpen, 3 alcohols, and 12 others (Table 1). The detailed information is shown in Table S1. In the different types of analyzed honeycomb, a lot of compounds were identified: including 97 in ACC and 84 in AMC. Among them, 13 compounds (benzeneateddehyde, nonanal, decanal, styrene, heptadecane, nonadecane, heptacosane, 2-nonanone, ethyl octoate, ethyl nonanoate, ethyl caprate, \(\alpha\)-cedrene, 2-phenylethylanol) were detected in all samples.  
Quantitatively, the relative contents of each component differed among VOCs from different bee species' honeycombs. For instance, phenethyl acetate was detected only in all ACC samples, whereas furfural and linaloal were detected only in all AMC samples (Table S1). Consequently, in order to find marker compounds that could be used for the comparison of ACC and AMC, an independent samples \(t\)-test analysis was employed for analyzing the relative contents of the peaks of honeycomb [19]. As shown in Figure 2 and Table S1, there were significant differences in VOCs between them. The main VOCs of ACC included 2-Phenylethanol (average 5619.78 \(\upmu\)g kg\({}^{-1}\)), trans-linalo oxide (average 4134.56 \(\upmu\)g kg\({}^{-1}\)), and lanlool oxide (average 3884.36 \(\upmu\)g kg\({}^{-1}\)). The main components of AMC included octanal (average 2455.65 \(\upmu\)g kg\({}^{-1}\)), lanlool oxide (average 2387.28 \(\upmu\)g kg\({}^{-1}\)), and furfural (average 1786.01 \(\upmu\)g kg\({}^{-1}\)). In general, the contents of hydrocarbons, ketones, ester, terpenes, alcohols, and others, were higher in ACC than in AMC (Table 1). It is worth noting that there is a significant difference between ACC and AMC in the content of ketones, esters, and alcohols (\(p<0.05\)) (Table 1). The average contents of ketone in ACC and AMC were 4257.70 \(\upmu\)g kg\({}^{-1}\) and 883.58 \(\upmu\)g kg\({}^{-1}\), respectively, including 2-heptanone, sulcatone, acetophenone, 2-nonanone, isophorone, 3-Nonen-2-one, 4-oxoisophorone, dihydroxyophorone, 2-undecanone, damascenone, \(\beta\)-ionone. The average contents of esters in ACC and AMC were 7707.52 \(\upmu\)g kg\({}^{-1}\) and 2154.96 \(\upmu\)g kg\({}^{-1}\), respectively, including ethyl octoate, ethyl nonanoate, ethyl caprate, ethyl phenylacetate, phenethyl acetate, etc. The average contents of alcohol in ACC and AMC were 6008.73 \(\upmu\)g kg\({}^{-1}\) and 2154.96 \(\upmu\)g kg\({}^{-1}\), respectively, including ethylhexanol, benzyl alcohol, 2-phenylethanol (Table S1). However, the total VOC contents ranged from 10,077.61 to 48,933.33 \(\upmu\)g kg\({}^{-1}\) of AMC, and 12,596.05 to 80,840.77 \(\upmu\)g kg\({}^{-1}\) of ACC. The total VOC amount showed no significant differences between the two different honeycomb extracts.  
Terpenes were the main VOCs present in ACC, followed by esters (Table 1). The most abundant terpen in ACC, of which the average content was above 1000 ug kg\({}^{-1}\), were trans-linalool oxide (4134.56 ug kg\({}^{-1}\)), linalool oxide (3884.36 ug kg\({}^{-1}\)), cedrol (2347.24 ug kg\({}^{-1}\)), caryophyllene (1133.73 ug kg\({}^{-1}\)) and cedr-8-ene (1010.68 ug kg\({}^{-1}\)). Terpenes were also the main VOCs present in AMC, followed by aldehydes.