Detection of Maillard Reaction Product [5-(5,6-Dihydro-4H-pyridin-3-ylidenemethyl)furan-2-yl]methanol (F3-A) in Breads and Demonstration of Bioavailability in Caco-2 Intestinal Cells.

[5-(5,6-Dihydro-4H-pyridin-3-ylidenemethyl)furan-2-yl]methanol, also called F3-A, has been isolated from hexose-lysine Maillard reaction (MR) models. Here we report on optimized conditions for the recovery of F3-A and concentrations found in bread. Recovery of F3-A was best achieved when samples were extracted with dichloromethane (DCM) at a solvent to sample ratio of 2:1 (v/v) after adjustment of the pH to 12. The amount of F3-A in whole wheat bread was significantly (P < 0.05) higher than that in white bread; bread crust contained a significantly (P < 0.05) higher amount of F3-A (0.9-7.8 μg/100 g) than the bread crumb (not detectable-3.5 μg/100 g); and toasting increased F3-A concentration with a range of not detectable to 6.0 μg/100 g in the control bread and 4.0 and 17.7 μg/100 g in the dark-toasted white sandwich bread and 100% whole wheat sandwich bread, respectively. The in vitro permeability of F3-A was measured using Caco-2 cell monolayer. The apparent permeability coefficient (Papp) of F3-A is (6.01 ± 0.35) × 10(-5) cm/s, which is similar to that of propranolol, a highly passive transcellular absorbed drug. In conclusion, the concentration of F3-A recovered in bread varies with the type of bread and degree of toasting, and F3-A is bioavailable.