## 4 Conclusions  
To obtain faba leaves with rich nutrition and a good flavor, a cooking time of 5 min is recommended for all the domestic cooking methods investigated in the present study. Compared with fresh faba leaves, those cooked by microwaving and steaming exhibited a significantly increased \(\iota\)-dopa content. The content of flavonoids, particularly kaempfer glycosides, increased in leaves after the roasting treatment. Of the cooking methods studied, boiling had the strongest effect on reducing both the non-volatile compounds and VOCs. Alcohols, aldehydes, ketones, and esters formed more than 90% of the VOCs detectedin the fresh faba leaves, but their contents were significantly reduced after cooking. In contrast, the content of alkanes increased significantly after the microwaving and roasting treatments. Aromatic hydrocarbons increased, particularly in faba leaves treated by microwaving, significantly increasing the contents of the relatively harmful \(p\)-xylene and newly synthesized naphthalene derivatives. Importantly, the microwaving and steaming treatments both significantly increased the antioxidant activities of the faba leaves. The \(\iota\)-dopa content and antioxidant activities of the processed faba leaves were also strongly positively correlated. Overall, all of the cooking methods tested in this study can be applied to faba leaves to remove undesirable flavors, with microwaving and steaming being recommended to significantly improve the antioxidant activities and \(\iota\)-dopa content; however, the use of microwaving may be limited by the significantly increased \(p\)-xylene content, which may have harmful effects on human health. Further studies should therefore be considered to clarify any negative effects of applying microwave treatment when cooking faba leaves for reasons of food safety. In addition, the sensory evaluation and bioaccessibility analysis of domestically cooked faba leaves should also be performed in further studies.  
The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/antiox11050931/s1](https://www.mdpi.com/article/10.3390/antiox11050931/s1)]([https://www.mdpi.com/article/10.3390/antiox11050931/s1](https://www.mdpi.com/article/10.3390/antiox11050931/s1)), Table S1: Correlation coefficients between antioxidant activities and metabolite groups assembled with processed faba samples, Table S2: The volatile flavor profiles of faba leaves before and after domestic cooking.  
Conceptualization, S.H.E. and S.-J.K.; methodology, S.D. and S.H.E.; software, S.D. and C.S.G.; validation, C.S.G. and S.H.E.; formal analysis, S.D.; investigation, S.D. and S.-J.K.; data curation, S.D. and S.H.E.; writing--original draft preparation, S.D. and S.-J.K.; writing--review and editing, S.H.E. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Research Foundation of Korea (NRF) grant number NRF-2022R1A2C100769511 and also supported by the research program of Korea Atomic Energy Research Institute, Korea.  
Not applicable.  
The data presented in this study are available in article and Supplementary Materials.  
The authors declare no conflict of interest.