Changes of flavonoid glycosides by blanching in Korean Naeng-i (Capsella bursa-pastoris (L.) Medik.) using UPLC-DAD-QToF-MS and UPLC-QTRAP-MS/MS

Capsella bursa-pastoris (L.) Medik. (Brassicaceae), commonly known as Naeng-i in Korea, is a spring vegetable widely consumed in traditional dishes for its nutritional and health-promoting properties. However, comprehensive profiling of flavonoid composition remains limited. In this study, twenty-five flavonoid glycosides in Naeng-i were identified and quantified from different cultivation regions and under blanching treatment using UPLC-DAD-QToF-MS and UPLC-QTRAP-MS/MS. Flavones constituted approximately 94.0% of the total flavonoids, mainly as C - and O -glycosides of luteolin, apigenin, and chrysoeriol. Among them, twelve compounds were tentatively characterized for the first time in this source, with their MS fragmentation described as positive ion mode. Notably, C -glycosides were predominant, including isoorientin 2″- O -arabinoside and isoorientin 2″- O -glucoside, exhibiting significant variability among cultivation regions. Total flavonoid content in raw samples ranged from 324.6 to 504.9 mg/100 g dry weight and decreased after blanching by 32.2% (Hongseong), 21.8% (Goseong), 20.6% (Iksan). Moreover, ten chemical markers by cultivation regions were identified through PLS-DA analysis. This study provides detailed flavonoid profiles and expands the phytochemical understanding of the underexplored vegetable Naeng-i , with a particular focus on C -glycosides. These findings offer fundamental data on its edible forms (raw and blanched), supporting future metabolomics research and its potential use as a dietary supplement.