Abstract:

An analytical method was established to determine the contents of resveratrol (Res) and polydatin (PD) in mulberry using HPLC with phenomenex C18 column (150 mm × 4.6 mm, 4μm) based on gradient elution with MeOH/H2O at a rate of 0.8 mL/min and detection at 305 nm. The method exhibited good linearity over concentration ranges from 0.5 to 50μg/mL for Res and from 2 to 100μg/mL for PD. The mean recoveries (n = 3) for Res and PD at 3 spike levels were 99.0% and 98.28%, respectively, with corresponding RSDs of 3.86% and 1.18%. The content of PD was always higher than that of Res throughout the whole maturation phase. Both compounds reached their separate maximum levels in mid-red period; however, a slight reduction was observed in the purple period. Meanwhile, Xinong 1 had the highest level of total Res (original Res plus Res derived from hydrolyzed PD), reaching up to 94.5μg/g. Therefore, mulberry is rich in Res and the best harvest time should be the initial period of fruit color change from red to purple.

Key words: mulberry, resveratrol, polydatin, determination, high-performance liquid chromatography (HPLC)