Investigation of the retronasal flavour release during the consumption of coffee with additions of milk constituents by'Oral Breath Sampling'

The aim of this study was the investigation of the influence of milk proteins (casein and whey proteins) and milk fat on the release of flavour compounds from white coffee beverages in the oral cavity. For this reason a retronasal headspace technique for measurement of the after-flavour was adapted. A 'Gas Sampler' equipped with a mouthpiece was used as an 'Oral Breath Sampler (OBS)'. Analyses were performed by gas chromatography with mass spectrometric detection. It was noticed that the sampling at different hours resulted in different standard deviations. The flavour release is more constant in the morning (Variation coefficient from 3% to 28%; median: 10%) than in the afternoon (7-52%; median: 23%). The relationships between flavour release and some salivary parameters like salivation rate, buffer capability and protein content were also studied. The 'Oral Breath Sampling' was considered to be a valuable sampling method for the analysis of the retronasal aroma release from coffee beverages.