Analysis of Flavonoid Metabolites in Citrus reticulata 'Chachi' at Different Collection Stages Using UPLC-ESI-MS/MS

Yuting Chen; Yujuan Xu; Jing Wen; Yuanshan Yu; Jijun Wu; Lina Cheng; Wai-San Cheang; Wenwen Liu; Manqin Fu

doi:10.3390/foods12213945

Analysis of Flavonoid Metabolites in Citrus reticulata 'Chachi' at Different Collection Stages Using UPLC-ESI-MS/MS

Foods. 2023 Oct 28;12(21):3945. doi: 10.3390/foods12213945.

Authors

Yuting Chen^{1

2}, Yujuan Xu¹, Jing Wen¹, Yuanshan Yu¹, Jijun Wu¹, Lina Cheng¹, Wai-San Cheang³, Wenwen Liu⁴, Manqin Fu¹

Affiliations

¹ Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, No. 133 Yiheng Street, Tianhe District, Guangzhou 510610, China.
² College of Food and Pharmaceutical Engineering, Wuzhou University, Wuzhou 543002, China.
³ Institute of Chinese Medical Sciences, State Key Laboratory of Quality Research in Chinese Medicine, University of Macau, Macao SAR 999078, China.
⁴ Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.

Abstract

Flavonoids are essential substances with antioxidant properties and high medicinal value. Citrus reticulata 'Chachi' peel (CRCP) is rich in flavonoids and has numerous health benefits. The different maturity periods of CRCP can affect the flavonoid contents and pharmacological effects. In this study, we successfully performed UPLC-ESI-MS/MS-based metabolic analysis to compare the metabolites of CRCP at different harvesting periods (Jul, Aug, Sep, Oct, Nov, and Dec) using a systematic approach. The results revealed the identification of a total of 168 flavonoid metabolites, including 61 flavones, 54 flavonols, 14 flavone C-glycosides, 14 dihydroflavones, 9 flavanones, 8 isoflavones, 3 flavanols, 3 dihydroflavonols, and 2 chalcones. Clustering analysis and PCA were used to separate the CRCP samples collected at different stages. Furthermore, from July to December, the relative contents of isoflavones, dihydroflavones, and dihydroflavonols gradually increased and flavanols gradually decreased over time. The relative content of flavonoid C-glycosides showed an increasing and then decreasing trend, reaching the highest value in August. This study contributes to a better understanding of flavonoid metabolites in CRCP at different harvesting stages and informs their potential future utilization.

Keywords: Citrus reticulata ‘Chachi’; OPLS-DA; PCA; UPLC-ESI-MS/MS; flavonoid metabolites.

Grants and funding

This study was supported by the project of the National Key R&D Program (2021YFD1600104), the project of the Guangdong Natural Science Foundation (No. 2021A1515011049), the project of Guangzhou Science and Technology planning (No. 2023B03J1370), the Collaborative Innovation Center of GDAAS (No. XTXM 202205), and the project of the Guangdong Academy of Agricultural Sciences (No. R2020PY-JX011; No. 202109TD).