Study On The Method And Application For Detecting Content Of Selected Flavonoids In Vegetables And Fruits

Flavonoids have a wide range of biochemical and pharmacological effects,including antiinflammatory, antioxidant and antiproliferative actions. However, it isrecognized that the effect of flavonoids on human health depends on their intake andbioavailability. So far, there are few data about the estimate of the daily flavonoidintake in China. The reason may be that there is not yet a rapid, accurate method fordetecting flavonoid content in vegetables and fruits, and there is not a completedatabase of flavonoid content in vegetables and fruits. Therefore, this studyestablished a simple, rapid and sensitive reversed-phase high-performance liquidchromatographic method for the simultaneous determination of five flavonoidcompounds (apigenin, luteolin, quercetin, kaempferol and isorhamntin) in vegetablesand fruits; We used the method to analyze content of five flavonoids in109types ofedible vegetables and fruits; We further investigated the relationship between theintake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin and theircorresponding plasma concentrations.First, a simple, rapid and sensitive reversed-phase high-performance liquidchromatographic method for the simultaneous determination of five flavonoids invegetables and fruits has been established. The separation was performed on a C18column with0.1%phosphoric/methanol (v/v,2/3) at30℃, and the wavelength was setat339nm with a diode array detector.Second, we used the established RP-HPLC method to analyze both thecomposition and content of flavonoids in109types of edible vegetables and fruitscommonly consumed in Harbin city. The predominant flavonoids found in the largestabundance in all of the analyzed foods was quercetin; The content range of quercetin, kaempferol, isorhamnetin, apigenin and luteolin were0-37.97mg/100g,0-48.2mg/100g,0-33.36mg/100g,0-55.11mg/100g和0-18.4mg/100g, respectively;The composition and content of flavonoids in different foods were different. And thedata about content of five flavonoids were applied to investigate the relationshipbetween the intake of quercetin, kaempferol, isorhamnetin, apigenin and luteolin andtheir corresponding plasma concentrations. Flavonoid intake and their plasmaconcentrations were analyzed in ninety-two subjects consuming their habitual diet;Flavonoid intake was estimated with7-d dietary records using available data on theflavonoid content of food; Plasma flavonoid concentrations were quantified by HPLC;The mean7d-intake of five flavonoids were positively correlated to theircorresponding plasma concentrations, with correlation coefficients ranging from0.33to0.51(P<0.05).This study contributes to the establishment of China’s flavonoid database,provides a basis for the assessment of the daily flavonoid intake and also provides abasis for epidemiological studies investigating the health effects of flavonoids.