HPLC-DAD-ESIMS analysis of phenolic compounds in bayberries (Myrica rubra Sieb. et Zucc.)

Qualitative analysis of the ethyl acetate extracts from three bayberry cultivars, Xiangshan, Biqi and Dongkui, was performed by means of a hyphenated technique of HPLC coupled to photodiode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESIMS). Three phenolic compounds were identified (gallic acid, protocatechuic acid, and quercetin 3-glucoside) and seven others (two myricetin hexoside and two myricetin deoxyhexoside derivatives; quercetin hexoside and quercetin deoxyhexoside derivatives; kaempferol hexoside derivative) partially identified. Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that gallic acid (2.6–7.0 mg/kg FW) was the major phenolic acid in all analysed cultivars. Myricetin glycosides (71.1 mg/kg FW) were the major flavonol glycosides in cultivar Xiangshan and quercetin glycosides (117.8 mg/kg FW) were the major ones in cultivar Biqi. Cultivar Dongkui had medium contents of quercetin glycosides (48.0 mg/kg FW) and myricetin glycosides (53.2 mg/kg FW). Kaempferol glyosides (3.1–4.6 mg/kg FW) were the lowest contents of flavonol glycosides in the assayed bayberries. These results are relevant not only from a nutritional point of view, but also in the control of color stability and haze formation during bayberry juice processing and storage.