It is a form of fraud 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 confidence in cooking oil as a foodstuff. At Rhine-Waal University of Applied Sciences, the young scientist Kilian Visser, a student at the Faculty of Life Sciences, has taken up the fight against this problem. For his work, he has now been awarded the Heinrich Stockmeyer Foundation’s Young Scientist Prize, worth 2,500 euros. The award was presented by Prof. Dr Dr 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 work 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 tackle this problem, Visser investigated in his Master’s thesis the potential of so-called Raman spectroscopy, a method in which the laser light reflected by the material under examination is analysed. Using a Raman microscope, Visser took the chemical ‘fingerprints’ of a total of 27 cooking oil samples from 15 different types of oil and created a database of around 1,800 Raman spectra. For example, he investigated how a slight change in the laser’s focus within the measured drop of cooking oil affects the measurement result.
Visser’s innovation lies in the data analysis: in his work, he combined established analytical methods with modern machine learning techniques. The result is a method which, when used in practice, can reliably detect refined sunflower oil in virgin olive oil with very high precision – at a concentration as low as 0.25 per cent. The measurements take only a few seconds. The method therefore has the potential to improve quality control in the food industry and official food safety monitoring. “It is practice-oriented, highly scientific and presented in a well-founded manner,” said Prof. Gareis, praising the work, which was unanimously deemed worthy of the prize by the Board of Trustees.
For Kilian Visser, this brings things full circle. He has remained loyal to the university even after completing his studies: following his bachelor’s degree in ‘Quality, Environment, Safety and Hygiene’ and his subsequent master’s degree in ‘Food Sciences’ at the Faculty of Life Sciences, he now works as a research assistant in the faculty’s food science department. He sees great potential in the method and considers it entirely conceivable that it could be adapted for use on portable systems in the future, enabling measurements to be taken directly on site. Such a development could transform the landscape in the fight against food fraud and boost consumer confidence in the long term. The Master’s thesis was supervised by Prof. Dr Florian Kugler, Professor of Food Science and Technology, and by Thomas Tewes, a research assistant and PhD student at the Faculty of Life Sciences.
