In vivo monitoring of strawberry flavour release from model custards:: effect of texture and oral processing

The interaction of oral processing protocols and food texture on in vivo flavour release was evaluated by nose-space analysis. Nose-space analysis was carried out by proton transfer reaction mass spectrometry, and strawberry-flavoured custards were prepared with 0.1% (w/w) and 1.0% (w/w) carboxymethyl cellulose to modify the texture. Two oral processing protocols were adopted during the study; a free-chewing protocol and an imposed protocol. Twenty-one subjects participated in the study. Significant effects on in-nose flavour release were observed for the type of compound, the custard's texture, the oral processing protocol and the subjects. When people were allowed to eat as they normally do, individuals could be divided into three groups on the basis of swallowing time: first group, swallowing time < 4 s; second group, swallowing time > 6 s; intermediate group, t((swallow)) varying (4-6 s). Within each group, different effects of the texture of the custards on in-nose flavour concentrations were observed, indicating that individual behaviour plays a considerable role in determining texture effects on flavour perception. Copyright (c) 2006 John Wiley & Sons, Ltd.