This page presents the results of the PROMETHEUS project. A summary of the key findings is provided for each technology covered by the project. You can also download the final report (PDF document, 37 pages in total).

Monitoring strategies

Front face fluorescence
Fluorescence spectroscopy is an accurate, sensitive, non destructive and real time analytical tool potentially fulfilling various objectives at the R&D and production levels.

In R&D departments, the analyzer Fluoralys developed by Spectralys in the frame of PROMETHEUS can be used to save time and money. The real time and global analysis of product quality allows getting a rapid diagnosis on the effect of experimental parameters tested in a design, and further concentrating on the only parameters of real interest. A set of conventional methods can then be applied to have a precise and complete understanding on those influencing parameters. It allows, for example:
- to perform a rapid diagnosis of positive and negative factors influencing the formation of processing contaminants;
- to deduce significant improvement or reduction of quality level in the final product;
- to optimize recipes or process parameters with a considerable time saving.
The multicriteria approach allows controlling simultaneously positive and negative quality criteria making it possible to mitigate PC while maintaining or improving the microbiological, sensorial and nutritional quality parameters. Such an approach has been initiated in the scope of biscuit baking, where acrylamide mitigation can be obtained without changing the color and water content.

In industrial production, Fluoralys can be used as a real time quality control system for parameters where NIR or other spectral analytical tools fail in providing sufficient reliability, for example for processing contaminants, nutritional quality and sensorial quality. The example is given of the simultaneous quantification using Fluoralys of acrylamide, humidity, color, and texture in biscuits.

Moreover, a real use of Fluoralys as PAT (Process Analytical Technology) can also be envisaged. Fluoralys can be used in line in an oven for biscuit quality control, by using the multicriteria approach on quality parameters to be standardized in the final biscuit. The corrective actions to reach the standard quality based on the levels measured at a critical point of the process must be defined first.

Based on this understanding of how process parameters influence each quality parameters, using the optimization approach described just above, assessing the quality at the end of the process and at the critical point should allow applying the suitable parameter changes to reach the quality standard.

More details: PDF download

Contact: Ines Birlouez, Spectralys Innovation (France)
ines.birlouez (at)

Ambient mass spectrometry
The DART–HRMS technique demonstrated an interesting potential to enable high-throughput fingerprinting of biscuit samples applicable in control of some quality / safety parameters. The multivariate analysis of fingerprint data (mass spectra of sample extract) provided insight into the chemical differences between biscuits prepared according to different recipes and made it possible to follow changes in the chemical composition of samples during the baking process.

The concentrations of acrylamide formed during the baking of biscuit could be predicted with acceptable accuracy based on combined use of multivariate data obtained by positive and negative mode DART–HRMS and chemo-metric modelling.

The PLSR prediction model developed was proved to be robust against small changes in biscuit recipes (i.e., presence / absence of NaCl at approximately 0.6%, w/w). However, the robustness of the model should be further investigated by studying variations in chemical compositions of raw materials such as flours used for the preparation of the biscuits. Studies on effects of varying contents of asparagine and reducing sugars, which are the main precursors of acrylamide, would be particularly helpful.

A predictive model such as that could be used for a rapid screening of biscuits to assess the impact of changes in processing conditions or formulation on acrylamide formation.

More details: PDF download

Contact: Jana Hajslova, VSCHT (Czech Republic)
jana.hajslova (at)

Computer Vision Based Image Analysis
The objective was to develop a computer vision-based image analysis tool to monitor the development of surface browning in biscuits, and hence to predict the changes in the concentrations of processing contaminants (PCs) such as acrylamide and hydroxymethylfurfural in biscuits during baking.

Two computer vision based image analysis algorithms were developed for the extraction of mean colour (CIE a value) and featured colour (brown ratio) information from the digital images of biscuits. Based on these algorithms, a camera prototype was developed for online color measurement to monitor acrylamide and HMF formation in biscuits during baking. Using the calibration models for a fixed biscuit recipe, surface color could be monitored online by means of the camera prototype to predict PCs under real processing conditions.
The calibration models are specific to the recipe used. Any changes or modifications in the recipe would require validating the calibration models, and if required, new calibration should be built for the modified recipe.

In conclusion, computer vision based image analysis offers rapid, accurate, non-contact, and non-destructive analysis of foods. It provides a high level of flexibility at relatively low cost and high throughput. Besides, it can be implemented online as an integral part of baking lines for real time monitoring of product quality and safety.

More information: PDF download

Contact: Vural Gökmen, Hacettepe University (Turkey)
vgokmen (at)
  Next: Mitigation strategies
This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 265558
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