Influence of Oral Physiological Parameters on In vitro Dynamic Flavour Release from Dried French Beans Determined by Proton Transfer Reaction Mass Spectrometry

The influence of the oral physiological parameters mastication and salivation was evaluated for in vitro flavour release from rehydrated dried French beans. Four mastication rates (0, 26, 52 and 78 rpm), four saliva volumes (0, 20, 40 and 60% v/w) and the four volatile flavour compounds 2-methylpropanal, 2- and 3-methylbutanal, and hexanal were examined. Equilibrium headspace analysis was carried out by static headspace gas chromatography. Dynamic headspace analysis involved combined model mouth/Proton Transfer Reaction-Mass Spectrometry. Saliva reduced the equilibrium headspace concentrations of the flavour compounds by 24-63%. Addition of saliva had no effect on the maximum intensity measured under dynamic conditions (multivariate analysis of variance, P<0.05), but it increased the flavour compounds` persistence. Increase of mastication rate resulted in higher maximum intensities, as well as increased persistence. The proportions of the compounds were hardly affected by the two oral physiological parameters.