Concentration and solubility of flavanones in orange beverages affect their bioavailability in humans

Orange juice is a very rich source of dietary flavanones. The effect of flavanone concentration and solubility of orange beverages on their bioavailability has been studied in a crossover study with 10 healthy volunteers. Five different beverages with different flavanone concentrations were evaluated. Commercial orange juices (29.2-70.3 mg of flavanones/100 mL) were compared with experimental orange beverages in which the flavanone concentration was enhanced (110.2 mg/100 mL). Hesperetin and naringenin glucuronides and sulfates were detected and quantified in plasma and urine. The study shows that the solubility of the flavanones, and particularly that of hesperidin, in the juice is a key factor for the bioavailability as flavanone excretion and the C(max) in plasma correlate well with the soluble flavanone concentration in the juice, whereas it has no correlation with the total flavanone intake. In addition, a large interindividual variation was observed, this being consistent for each individual after the intake of the different beverages, suggesting that flavanone bioavailability is also dependent on the occurrence of specific microbiota that is able to remove the rutinosides from the juice glycosides, which results in aglycones that are then absorbed from the gut.