Food and Flavor Science
Measurement of espresso coffee headspace with PTR-MS
This novel and efficient approach of characterizing the aroma of coffee blends by on-line analysis may shorten the time required for the development of new products and improve quality control in a more automated and objective manner.
Analytical studies and sensory profiling is performed on different commercially available espresso coffee products. On-line analysis with IONICON PTR-MS is used to obtain chemical information about difference in composition of the coffee headspace characterizing the different coffee blends. In addition, an expert panels trained for coffee tasting describe each sample by scoring 10 key flavor attributes on a 10-point scale.
The overall sensory description of each sample is correlated with the analytically obtained differences in chemical composition in order to develop a statistical tool to predict the sensory profile based on analytical data. In a second step, the prediction is validated using a new series of coffee blends, which differ in the aroma profile and which are not included in the development of the predictive
tool.
The overall sensory prediction of the new blends based solely on the analytically generated data shows a good match with the sensory profiles independently obtained by the expert panel.
When PTR-MS Tastes Coffee: Instrumental Approach To Predict the Sensory Profile of Espresso Coffee
A major step forward in terms of correlation of sensory with instrumental
results has been achieved by Lindinger et al* of the Nestlé Research Center in Switzerland using IONICON PTR-MS.
The scientists were able to develop a robust and reproducible model to predict the sensory profile of espresso coffee from instrumental headspace data.
Related articles in press:
*C. Lindinger, D. Labbe, P. Pollien, A. Rytz, M. A. Juillerat, C. Yeretzian, I. Blank, When Machine Tastes Coffee: Instrumental Approach To Predict the Sensory Profile of Espresso Coffee. Anal. Chem. (2008). Link
Article in The New York Times.
Story at MSNBC.
PTR-MS online measurement of fruit flavor in the nose space air
PTR-MS with its online measurement capabilities enable researchers to quantify compounds in the nose
space air of test persons.
A very low detection limit and a high time resolution allow for online breath by breath analysis.
Insights for aroma design and flavor research can be gained through correlations between individual food perception and measured in-nose aroma concentration.
Results of PTR-MS measurements - chewing of strawberries
The graph shows a peak of isoprene with each exhalation occurring approximately every eight seconds, because of endogenous production of isoprene (red line). When strawberries are chewed (beginning after 80 seconds) compounds like methy-2methyl-butanoate, appear with each exhalation.
Determining the freshness of food in the consumer's perceptions with PTR-MS
Consumers have a definite appreciation of what constitutes freshness, based upon their individual experiences. For food&flavor science PTR-MS can be the ideal tool to link descriptive sensory analysis with objective fingerprinting of food volatiles.
Scientists* have shown that for bread an objective understanding of the freshness can be derived by relating consumer freshness judgments to sensory descriptive analysis and volatile composition.
Learn more about this application and download the poster.
* Heenan S., Dufour J.-P., Harvey W., Delahunty C., University of Otago
Related document:
Download an application flyer on food and flavor research (0.3 MB .pdf)
Download the presentation: Online quantitative analysis of volatile flavour compounds, food & flavour science (shown at Weurman-Symposium 2008) (2 MB .pdf)
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