# Flavoromics Analysis of Passion Fruit-Roasted Chicken
## 2 Results and Discussion
### Changes in Volatile Flavor Components during Preservation Process  
The flavor component changes in the roasted chicken made from passion fruit after vacuum compression and other packaging within 30 days are shown in Table S8. During the 30-day storage period, a total of 70 volatile flavor components were identified, which was 21.34% less than the number of types identified during the processing. The types and content of volatile flavor components showed a pattern of first increasing and then decreasing. Studies have reported that the types and contents of aldehydes, ketones, hydrocarbons, and heterocyclic compounds in preserved duck jerky continue to decrease [47]. After 10 days of storage, the total amount of volatile flavor components decreased from 2844.18 ng/g to 2163.87 ng/g at the end of roasting, indicating a high degree of aroma retention. After 15 days, the total amount significantly increased (\(p<0.05\)), and flavor precursor substances decomposed and transformed into volatile small-molecule substances. After 20 days, the main flavor substances were \(\beta\)-Caryophyllene and ethanol, which accounted for 33.26% of the total amount. After 30 days of storage, there were only 31 volatile substances, with the highest proportions of alcohols (618.49 ng/g) and hydrocarbons (632.16 ng/g) of up to 35.46% and 37.0%, respectively. During the storage period, no amine substances such as aniline, which can spoil the flavor, were detected. From the classification of functional groups of volatile aroma compounds, it can be seen that during the storage period, the volatile flavor components were still mainly aldehydes, ketones, alcohols, esters, and hydrocarbons, with a high degree of retention of various compounds. Among them, hydrocarbon substances were the primary flavor components during the storage period, consistent with the processing and roasting stages. The analysis of flavor components for different classifications is described next. Figure 5: Correlation between characteristic volatile components and flavor precursor substances in passion fruit-roasted chicken. Figure 5 was produced by OriginPro 2022. A total of 10 types of aldehydes were identified, and there were 7 types of aldehydes in the first 10 days. As the storage period extended, the types of aldehydes gradually decreased, and after 15 days, they significantly decreased. On the 30 th day, there were only three types of aldehydes (benzaldehyde, nonanal, and nutmeg aldehyde), and the content of aldehydes was only 29.80% of the highest value during the storage period (731.28 ng/g). Nonanal always exists during the processing and storage period, which, along with other small components, forms the characteristic flavor of passion fruit-roasted chicken. Seven types of ketones were identified during the storage period, and their types and contents significantly decreased after 20 days (\(p<0.05\)). After 30 days, only two types of ketones were present. Among them, the preservation effect of ethyl maltol was the most obvious, and the content gradually decreased within the range of 53.66-280.57 ng/g within 30 days, which is related to the fragrance-holding and shelf-life-extension functions. Dihydrogen-\(\beta\)- Violet ketone was present throughout the entire preservation process, and when mixed with ethanol, it can produce a violet aroma. During the preservation period, seven types of alcohol substances were identified, including L-linalool, oxidized linalool, and \(\alpha\)- Terpineol, and three other alcohols were retained to a high extent. The overall content of L-linalool ranged from 16.14 to 45.72 ng/g, retaining the woody aroma of passion fruit-roasted chicken. The content of \(\alpha\)- turpentine alcohol was 20.88 ng/g after 25 days, and there was no significant change during the storage period. Ethanol was the primary alcohol substance during the storage period, accounting for more than 70% of the total alcohol content, and its content significantly increased with the extension of shelf life (\(p<0.05\)).