Physicochemical Properties And Antioxidant Spectrum-effect Relationship Of Medlar Honey

Medlar honey was a unique single nectar mainly produced in Ningxia,Qinghai and other northwest regions of China.It was usually light amber color and easy to form white and delicate crystals during storage.The physicochemical properties and antioxidant activities of14 samples of medlar honey from Qinghai and Ningxia were studied,and the fingerprint of medlar honey was constructed.Some major antioxidant components were identified through the Spectrum-Effect relationship.1.The physicochemical properties of medlar honey samples were determined in this study,including pollen analysis,color value,conductivity,pH,content of water,protein,proline,5-hydroxymethyl furfural,glucose,fructose and sucrose,alpha-amylase activity,free acid,lactone,and total acidity.The physical and chemical properties of medlar honey conform to the quality standard of honey stipulated in the national standard and method for the inspection of honey import and export.2.The contents of total phenolic acid and total flavonoids in medlar honey were 401-532mg GAE/kg and 7.19¹2.26 mg RE/kg,respectively.Medlar honey has strong antioxidant activity.Its DPPH free radical scavenging IC₅₀0 was 36.72¹2.26 mg/mL,FRAP?total antioxidant capacity was 152.7¹87.6 mg Trolox/kg?,and Fe²⁺complexing power was27.4⁴1.7 mg EDTA-2Na/kg.The total antioxidant capacity of Lycium barbarum honey was correlated with its total phenolic content?p<0.01?,and the Fe²⁺complexing ability of Lycium barbarum honey was highly correlated with total flavonoid content?p<0.01?.The results showed that the significant protective effect of medlar honey on DNA damage of lymphocyte induced by hydrogen peroxide in mice?77.12%?with a dose-effect relationship.3.The HPLC fingerprint of medlar honey was constructed by multi-wavelength fusion technology,and 35 common peaks were obtained.PCA and HCA were used to distinguish medlar honey,acacia honey and rape honey.4.Based on grey correlation degree,partial least squares regression analysis and BP neural network,the antioxidant spectrum-effect relationship of medlar honey was analyzed.The results showed that 2,3-dihydroxybenzoic acid,p-coumaric acid,naringin and kaempferol may be the material basis of antioxidant activity of medlar honey.