Food & Flavor Science
Aroma and its perception can influence buying decisions. It is therefore indispensable for the industry to understand what we smell and taste when e.g. drinking a cup of coffee or enjoying a piece of chocolate, at the very moment the flavour molecules hit our receptors.
Flavor and taste of food can also vary over time, depending on raw materials or production processes etc. For a consistent brand image however, the aroma quality of food should remain stable.
Coping with requirements such as very high time resolution, basically real-time and direct air sampling are challenges to traditional analytical techniques.
IONICON PTR-MS – ultra sensitive solutions for real-time trace VOC analysis
In order to provide scientists and the industry with a better understanding of sensory perception, IONICON provides real-time VOC analyzers and is the market leader in Proton Transfer Reaction – Mass Spectrometry (PTR-MS).
The key benefits include:
• Rich chemical fingerprints of food samples in real-time
• Head-space analysis of products without sample preparation
• Direct mouth- & nose-space air analysis
• Rapid screening of complex aroma systems due to soft chemical ionization and high-resolution mass spectrometry
• Monitoring of real-time variations in aroma
• Suitable for chemometric datamining
The results provided by IONICON PTR-MS enhance research, flavour & fragrance development, quality control and allow for process monitoring in food & flavour industries.
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.
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 real-time aroma-release 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 - mastication of strawberries
The graph shows a peak of isoprene (red line), an endogenous compound produced in the body, with each exhalation occurring approximately every eight seconds. When strawberries are chewed (start after 80 seconds) aroma compounds like methy-2methyl-butanoate, are released and can be measured in each exhalation.
For the real-time analysis of flavor compounds in nose-space air, IONICON has developed the N.A.S.E., an inlet system for PTR-MS optimized for this application.
PTR-MS in Saffron Quality Control
PTR-MS can be used in the quality control of saffron. Saffron is a spice derived from the flower of Crocus sativus, and is among the world's most costly spices by weight. Despite attempts at quality control and standardisation, an extensive history of saffron adulteration, particularly among the cheapest grades, continues into modern times.
By monitoring of VOCs from a minute amount of sample (35 mg) over a 5 weeks period researchers have found that the of initially dominant VOC safranal (m/z 151) decreased progressively. Nenadis et al. further report that examination of calculated and recorded fingerprints for various admixtures showed that PTR-MS VOCs analysis, in combination with chemometrics, could be used to screen for the presence of lower quality saffron in a commercial product in a few minutes. PTR-MS can be used in a complementary fashion, adding to the battery of advanced analytical techniques available to address the quality and authenticity issues of saffron.
Freshness of food in the consumer's perceptions
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