Assessment of flavonoids and volatile compounds in tea infusions of water lily flowers and their antioxidant activities

Water lily, a member of the Nymphaeaceae family, can be made into tea on the basis of outstanding fragrance characteristics and health care functions. In this study, 16 flavonoids were identified and quantified in tea infusions prepared from the petals of 33 water lily cultivars using HPLC-DAD and HPLC-ESI-MS/MS. The infusions were analyzed with HS-SPME coupled with GC-MS; 29 volatile compounds were detected, of which nine were found to be scent components. The cultivars were clustered into three clusters characterized according to scent components. The 'Conqueror' and 'Virginia' cultivars had the highest antioxidant activities. The concentrations of polyphenols and flavonoids showed significant positive correlations with antioxidant activity as measured by DPPH, ABTS+, and FRAP assays. This study is valuable for a fuller understanding of this important tea and can also be used for the development of water lily.