Faba beans are a promising alternative in the promotion of a sustainable food system: their protein content is high, they improve crop rotation and they thrive in cool climates, including Finland’s. However, faba bean consumption is restricted by the carbohydrates they contain known as raffinose-family oligosaccharides (RFO), which can cause abdominal discomfort.
The study investigated how the various ingredients of faba beans and treatment techniques affect the structure and properties of meat analogues, as well as their compounds that potentially cause abdominal discomfort.
“Our study highlights the potential of less refined faba bean raw materials in the development of plant protein–based meat substitutes. In addition, pre-treatment techniques, such as enzymatic treatment and fermentation, offer new opportunities for improving gut-friendliness and nutritional quality. These findings can facilitate consumer transitions towards diets based on plant proteins and promote food choices consistent with sustainable development,” says Doctoral Researcher Katja Kantanen from the University of Helsinki.
Limited processing of raw materials improves structure of faba bean products
The study demonstrated that protein concentrate, flour and other less refined ingredients based on faba beans promote the formation of the desired fibre-like structure of meat substitutes. In contrast, highly refined protein isolates reduced structure quality.
High-moisture extrusion is a process that can be used to produce meat-like structures from plant-based raw materials, such as faba beans. Using this process, the researchers tested the effect of various variables on the properties of faba bean ingredients, observing, among other things, that water content significantly affected the softness and colour of the product, but not the structure itself.
Pre-treatment techniques improve faba bean gut-friendliness
To reduce the amount of RFO compounds in faba beans, two pre-treatment techniques were tested in the study: enzymatic treatment and fermentation. Both techniques reduced the number of RFO compounds by more than 80%, resulting in a concentration within the recommended limits of a FODMAP diet, which aims to reduce poorly absorbed carbohydrates. By utilising these treatments, faba bean–based products can be made increasingly suitable for consumers with sensitive stomachs.
Enzymatic treatment was effective and had little effect on the structure and properties of the final product. In contrast, fermenting resulted in more significant changes: it weakened the formation of fibre-like structures while also producing nutritionally beneficial compounds, including vitamin B12. Fermentation furthermore reduced the quantity of compounds vicine and convicine, which may be harmful to certain consumer groups.
Public examination
Katja Kantanen, M.Sci. (food sciences) defended her doctoral thesis entitled ‘Faba bean ingredients in high-moisture extrusion and pre-treatments to reduce raffinose oligosaccharides’ on 31 October 2025 at 13.00 at the Faculty of Agriculture and Forestry, University of Helsinki. The public defence will take place in the Raisio hall (lecture room B2) of the Forest Sciences Building at Latokartanonkaari 7.
Dr Volker Lammers from the German Institute of Food Technologies (DIL) will serve as the opponent and Professor Maija Tenkanen as the custos.
The thesis is also available in electronic form through the
RFO compounds (raffinose-family oligosaccharides)
RFO compounds are carbohydrates found in plants, particularly legumes, that are not directly absorbed in digestion. Eventually broken down by gut bacteria, they can cause abdominal discomfort due to gas formation.
Vicin and convicine
Vicin and convicine are compounds occurring in faba beans that can be harmful to certain people, especially those with inherited G6PD enzyme deficiency (glucose-6-phosphate dehydrogenase deficiency). This deficiency can cause favism, a condition where these faba bean compounds can result in red blood cell breakdown.