Fat content, baking time, hydration and temperature affect flavour release from biscuits in model-mouth and real systems

The release of flavour from complex food systems like biscuits depends on various conditions during manufacture and eating. Biscuits were prepared with fat contents between 4% and 18% and flavoured with volatiles of different polarities (anethole, LogP 3.45; trans-2-hexenyl acetate, LogP 2.13). Volatile release was examined in a model system (headspace) and in-mouth (nosespace), using online-MS to measure volatile concentrations. Under- and over-working of the dough resulted in reduced volatile release. Increased baking time reduced the intensity of volatile release. Volatile release was found to depend on fat content, baking time and work input into the dough. Low-fat biscuits released a significantly higher amount of anethole in both headspace and nosespace compared to high-fat biscuits. Persistence of anethole was higher in the high-fat biscuits. In the model system, release of 3-methyl butanal was found to be dependent on hydration, whereas anethole release was dependent more on temperature changes. It was hypothesized that this was due to differences in polarity of the volatiles.