Comparative analysis of species and contents of flavonoids before and after honey refining / 中草药

ABSTRACT

Objective To study the changes of flavonoid components in honey before and after refining. Methods Six batches of honey from different sources were collected and refined based on Chinese Drugs Pharmacy. Solid phase extraction was used to enrich flavonoids from samples. HPLC-TQ-MS was established to determine the contents of 15 flavonoids in crude and refined honey, the separation was performed on a Thermo Accucore RP-MS (100 mm × 2.1 mm, 2.6 μm) column with the gradient elution of methanol-0.1% formic acid water, the flow rate was 0.3 mL/min, and the column temperature was 30 ℃. MS condition Electrospray ionization (ESI) source was applied and operated in the positive multiple reaction monitoring (MRM) modes. Results Twelve kinds of flavonoids in three species, flavonoids, dihydroflavonoids, and isoflavones, were detected in honey, which including quercetin, morin, xanthophyllin, kaempferol, apigenin, wogonin, galangin, chrysin in flavonoids; pinobanksin, naringin, and pinocembrin in dihydroflavonoids; genistein in isoflavones. There was significant difference in the species and contents of flavonoids between crude honey and refined honey. After refining, rutin and narirutin were detected which have not been reported in references, and the contents of 12 kinds of flavonoids have increased at different degrees. The contents of quercetin, morin, xanthophyllin, kaempferol, apigenin, wogonin, pinocembrin, and chrysin in linden honey have increased, but the contents of pinobanksin, naringin, and galangin have decreased; all the contents of the components in acacia honey have increased except apigenin, especially the quercetin and morin; The content of 12 kinds of flavonoids in the honey of various flowers and Chinese date honey all have increased. Conclusion Refining can change the species and contents of flavonoids in honey.