Ancient technique can improve the bland taste of beans

Faba beans are rich in protein and can easily be grown in Denmark – yet they are more often used as animal feed than as food for people. One of the main reasons is that their flavour does not meet consumer expectations compared to beef, pork, or chicken.

Researchers from the University of Copenhagen aim to change that. In a new study, they demonstrate how fermentation with well-known bacteria can reduce the characteristic “beany” off flavour, create new flavour compounds, and improve the quality of plant protein.

Understanding this is crucial, as flavour remains one of the main barriers to choosing plant-based protein.

“Consumers want food that resembles what they already know. A plant-based alternative to meat should not taste like beans. With natural fermentation, we have managed to reduce off flavours in faba beans that give them a distinctive ‘green’ taste, while at the same time improving the overall flavour,” says senior author Professor Lene Jespersen from the Department of Food Science.

New flavours – including umami

In the study, the researchers fermented protein extracts from faba beans using selected bacteria. They then analysed how the chemical profile of flavour compounds changed. This allowed them to identify which bacteria were most effective at reducing unwanted flavours while simultaneously generating new aromas.

“We can see that the plant protein from faba beans can develop nutty and umami-like flavours during fermentation. These are flavours that consumers generally appreciate, and this may make beans more attractive as a food ingredient,” says Lene Jespersen.

A natural alternative to additives

In addition to improving flavour, fermentation may offer an alternative to the use of additives in food production. Although fermentation is an ancient technology used in products such as bread, yoghurt, and beer, it is also a natural process.

“We want to support industry efforts towards what is known as clean labelling – meaning products without additives or E-numbers. This is something many consumers are increasingly looking for,” explains Lene Jespersen.

Fermentation can also extend shelf life and, in some cases, contribute beneficial microorganisms.

From cheese selections to plant-based selections

The potential extends far beyond faba beans alone. According to the researchers, fermentation and specialised microorganisms may help create a broader range of plant-based foods — an area that Lene Jespersen and her colleagues at the Department of Food Science are strongly focused on.

Denmark has long been a global leader in dairy innovation, where microorganisms are used to create a wide range of flavours and textures. The new findings suggest that similar approaches can be applied to plant proteins, allowing researchers to tailor flavour profiles by selecting specific bacteria.

This represents an important step toward developing plant-based products from beans and peas with more appealing flavours.

“Imagine being able to serve a plant-based platter in the same way we serve a cheese platter today – with a variety of products that taste good, offer diversity, and have a high protein content,” says Lene Jespersen.

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Fact box: What are faba beans?

Faba beans are a protein-rich legume containing around 25 grams of protein per 100 grams of dried beans. In processed ingredients, the protein content can be even higher.

They do not require nitrogen fertiliser and can be grown in both warm and temperate climates. They are cultivated in Denmark, across Europe, and globally.

Today, they are primarily used as animal feed.

Research shows that one of the main barriers to consumer acceptance is their flavour, often described as “green” or strongly beany.

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Fact box: About the study

The researchers used two groups of bacteria to ferment faba bean protein:

• Lactic acid bacteria, which can reduce unwanted beany flavours
• Bacillus, which can create fuller, umami-like flavours

The study is based on analyses of changes in aroma compounds rather than sensory testing in humans.

In a separate study, the researchers conducted consumer tasting trials and found that perceived flavours corresponded with the analytical results.

The experiments were conducted using protein extracts from faba beans – the same type of ingredient used in plant-based meat alternatives such as vegan chicken or minced meat products.

Fermentation was also shown to reduce antinutritional compounds in faba beans, thereby improving their suitability as a food ingredient.