Targeted screening and quantification of flavonoids in the flavedo of navel oranges at different growth stages based on metabolomics technology

Abstract

Plant-based food intake is essential for health promotion, especially in preventing chronic diseases. Flavonoids, as important bioactive substances found in citrus fruits, have a variety of health benefits, including antioxidant, anti-inflammatory, and cancer-inhibiting properties. This study used ultra-high performance liquid chromatography tandem quadrupole time of flight mass spectrometry to determine the flavonoids in the flavedo of navel oranges at different growth stages. Combined with chemometric methods to distinguish flavonoids at different growth stages, 15 differential flavonoids were deduced. In addition, the biomarker flavonoids in navel orange flavedo were quantified by high performance liquid chromatography mass spectrometry. The results showed that the contents of rutin, isosinensetin, and isorhamnetin all showed a trend of increasing and then decreasing during the growing period, while the contents of tangeretin and nobiletin would gradually decrease with the increase of fruit maturity. In addition, the analysis also revealed that the content of isorhamnetin was negatively correlated with the content of both narirutin and tangeretin, and it was hypothesized that isorhamnetin was in the same metabolic branching pathway as narirutin or tangeretin. The results of this study support the practical application of orange peel as a nutritional resource in functional foods.