Fingerprint of Phenolic Compounds and Abscisic Acid of Loquat Honey

Abscisic acid and thirteen phenolic compounds(gallic acid,catechin,caffeic acid,α-catechin,p-coumaric acid,ferulic acid,3,4-dimethoxycinnamic acid,rutin,quercetin,naringenin,luteolin,keampferol and apigenin) of loquat honeys from different provinces of China were analyzed by high performance liquid chromatography.Separations were carried out on a column(Welch XtimateTM C18;250 mm × 4.6 mm,5 μm) using methanol and 5% formic acid-water solution(v/v) at a flow rate of 0.8 mL/min within 50 min.The abscisic acid and phenolic compounds were detected with a photodiode-array detector at wavelength of 260 nm,285 nm and 320 nm.Fingerprints of loquat honeys were established by the Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine(Version 2004A).At the same time,the reference fingerprint was verified by the data of loquat honeys spiked with different concentrations of rape honey.The results showed that the 14 components has a good linearity in their respective concentration range(r =0.9990~0.9999).There were some differences in the concentrations of these 14 components among the honey samples.Among them,68.9% were α-catechin,abscisic acid and rutin,which were much higher than other components.Total phenolic contents of 10 brands of loquat honey samples varied from 263.4μg/100 g honey to 580.3 μg/100 g honey,and the average concentration of total phenolic acids was 249.3 μg/100 g honey,higher than total flavonoids.The similarity analysis discriminated the loquat honeys spiked with different concentrations of rape honey successfully.The method developed in this study was suitable for the separation of abscisic acid and 13 phenolic compounds.The reference fingerprint of loquat honey can be used for the identification and authentication of monofloral honey,which is significant for the functional analysis and quality control of honey.