Graduate of the Master’s programme in Food Science at Rhine-Waal University of Applied Sciences honoured for method to detect adulteration of cooking oil
Dr Stephan Hanf
It is a scam that often goes unnoticed, yet is systematic: the adulteration of high-quality olive oil with cheaper vegetable oils, such as sunflower oil. The damage is not merely economic; it also undermines trust in one of our most fundamental commodities.
At Rhine-Waal University of Applied Sciences in Kleve, a young researcher has now taken up the fight against this problem. On 29 July 2025, Kilian Visser received the Heinrich Stockmeyer Foundation’s Young Talent Award, worth 2,500 euros, for his Master's thesis at the Faculty of Life Sciences at Rhine-Waal University of Applied Sciences in Kleve. The award was presented by Prof. Dr. Dr. habil. Manfred Gareis, Chairman of the Foundation’s Board of Trustees, who travelled specially from Bavaria to underline the Foundation’s personal commitment.
“Successes are most rewarding when they are also recognised,” emphasised Prof. Dr Peter Scholz, Dean of the Faculty of Life Sciences, and thanked the Foundation for “building the future”. At the heart of the award-winning thesis lies a problem of great economic significance. “In Europe in particular, olive oil is a foodstuff that is very often and very readily adulterated,” explained award winner Kilian Visser. To address this problem, Visser investigated in his Master's thesis – which was supervised by Prof. Dr Florian Kugler, Professor of Food Science and Technology and Head of Degree Programme for the Master’s programme in Food Science, as well as Thomas Tewes, Research Associate and PhD student at the Faculty of Life Sciences – the potential of Raman spectroscopy. Using a confocal Raman microscope, he recorded the chemical fingerprints of a total of 27 cooking oil samples from a selection of 15 different types of oil, thereby creating a database comprising around 1,800 Raman spectra.
He placed particular emphasis on practical relevance. Among other things, he investigated the effects that a slight change in the laser’s focus within the droplet-shaped cooking oil samples has on the measurement results. The real innovation lies in the data analysis: Kilian Visser combined established multivariate methods with modern machine learning techniques. The result is a method which, even when validated in practice, can reliably detect adulteration of extra virgin olive oil with refined sunflower oil with very high precision at a concentration as low as 0.25%. The measurements themselves take only a few seconds. “It is practical, highly scientific and presented in a well-founded manner,” said Prof. Gareis, praising the work, which was unanimously deemed worthy of the award by the Board of Trustees.
For Kilian Visser, who has remained loyal to the university, this marks the completion of a circle: After completing his bachelor’s degree in “Quality, Environment, Safety and Hygiene” and his subsequent master’s degree in “Food Science” at the Faculty of Life Sciences, he now works there as a Research Associate in the food science department. He sees great potential in the method and considers it “entirely conceivable” that it will be adapted for portable systems in the future, enabling measurements to be taken directly on site. Such a development could reshuffle the cards in the fight against food fraud and strengthen consumer confidence in the long term.
Heinrich Stockmeyer Foundation
The non-profit Heinrich Stockmeyer Foundation supports applied research projects aimed at improving food safety and strengthening consumer confidence in food quality. It was founded 30 years ago against the backdrop of the BSE crisis to meet the need for scientifically sound data in the food sector. The Foundation’s Young Talent Award is endowed with 2,500 euros and recognises outstanding Bachelor’s and Master's theses with a strong practical focus.
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