Physicochemical Properties And Antioxidant Activity Of Longon Honey And Litchi Honey

Longan and litchi are the main nectariferous plants in the south of our country. Color of longan honey is light amber color, while color of litchi honey is light amber color or slightly darker. longan honey and litchi honey are popular among customers because these two honeys all possess fruity smell and flower fragrance, and taste sweet. Physicochemical properties, antioxidant activities and protecting effects on DNA oxidation damage of 14 longan honeys and 14 litchi honeys were analyzed in our study. Furthermore, amounts of 11 phenolic compounds in these two honeys were determined using HPLC method, and target compounds of these two honeys were identified based on their fingerprint chromatograms.1.Physicochemical properties of these two honeys were analyzed in our study, including moisture, ash content, acidity (pH value, free acids, lactone and total acids), color value, conductivity, contents of saccharides (glucose, fructose and saccharose), content of hydroxymethylfurfural (HMF), diastase activity, and ontents of proline and protein. The results showed that all the physicochemical values of the two types of honeys were met the national standard and the quality standard of the European Union.2.Contents of total phenols, total flavonoids, scavenging activities for free radicals of DPPH·and OH·, and reducing capacity for Fe3+ of these two honeys were all determined in our study. Average contents of total phenols and total flavonoids in longan honeys were 495.05±49.17 mg GAE/kg and 83.1±11.63 mg QE/kg, while the average contents in litchi honeys were 412.28±28.55 mg GAE/kg and 64.6±10.44 mg QE/kg, which were all less than those in longan honeys. Moreover, stronger scavenging activity for free radicals and reducing capacity for Fe3+ of longan honey were observed when compared with litchi honey. Results of correlation analysis showed that a close correlation existed among the content of total phenols and total flavonoids, the scavenging activity for free radicals, and the reducing capacity for Fe3+.3.Protecting effects on DNA oxidation damage of these two honeys were analyzed in our study. Strong protecting effects of longan honey and litchi honey were all observed according to the results of single cell gel electrophoresis and DNA electrophoresis, as well as the content of 8-OHdG in mice serum. The protecting effects improved along with the increasing of the amounts of honeys within a certain extent. The protecting effect on DNA oxidation damage of longan honey was observed to be stronger than that of litchi honey.4.Contents of 11 phenolic compounds in longan honey and litchi honey were detected, and fingerprint chromatograms of these two honeys were built in our study. Results showed that 14 peaks and 24 peaks were observed in longan honey and litchi honey, respectively, based on which, mutual chromatographic peaks of these two honeys were identified. In addition, target compounds of botanical origins of longan honeys and litchi honeys were identified with ellagic acid and para-hydroxybenzoic acid, respectively. Hesperetin and p-coumaric acid were not detected in any litchi honey samples.