Legumes: A Powerhouse of Health and Sustainability

2024.11.18

Birte van Ittersum holds an MSc in food technology, nutrition and gastronomy at Wageningen University in the Netherlands.

Birte van Ittersum’s Legumes Insights: More plant-based and less meat. This is the basis of the new Swedish dietary guidelines that will be presented in early 2025 by the National Food Agency. Ideally, we should eat legumes every day. By eating more legumes, such as yellow peas, lentils, and brown beans, and less fresh vegetables that are transported long distances, we can reduce our climate impact. The best option, of course, is if the legumes are grown in Sweden.

Why should we eat more legumes?

Legumes are small but mighty powerhouses offering many benefits. They are packed with nutrients and fiber, are gluten-free and have the ability to naturally enrich the soil with nitrogen. One key advantage is their high protein content, which makes them an ideal choice for boosting protein intake in vegetarian and vegan diets.

While the benefits of legumes are clear, legumes contributed a mere 1% of the protein supply in Sweden in 2013.

The vast majority of legumes are diverted to animal feed. Legumes consumed in Sweden are currently mostly imported from Canada, the United States, China, and Turkey. Research has shown that these imported legumes can have up to eight times higher greenhouse gas emissions compared to Swedish-grown legumes. At the same time, a 50% reduction of meat and replacing this with domestically grown legumes can reduce environmental impact by 20% and land use by 23%.

Legumes are packed with nutrients and fibers, they are gluten-free and have the ability to naturally enrich the soil with nitrogen.

How can we encourage people to eat more legumes?

In short, there is great potential for increased consumption of Swedish legumes. But how do we make people consume more, and preferably local, legumes? Soaking and cooking legumes at home is a hassle that not a lot of people are willing to go through. One way to boost legume consumption is by incorporating legumes into products we already love. Still, when incorporating legume flours into products, maintaining product quality remains a challenge. Therefore, emphasis should be on developing products that are both healthy and appealing to the consumer. With the protein transition in the back of our minds, it is vital to have products that offer a good source of plant-based protein. Thus, incorporating legumes into products could offer clear nutritional and environmental benefits.

A challenge here, however, is that legumes naturally contain anti-nutrients, such as phytic acid, which can limit digestion and nutrient uptake. Phytic acid has been shown to be reduced in legumes under the influence of processing steps such as soaking, heat treatment, fermentation, and germination. Thus, by treating the legume flours, anti-nutrient levels can be reduced.

Interestingly, legume flours have a much higher water absorption capacity than wheat flour, which could potentially improve the shelf stability of products, keeping them tender and flexible for longer.

This higher water absorption capacity can be attributed to the higher content of protein and dietary fiber, and specific carbohydrates called pentosans. Substances that swell in water can also potentially (partially) replace gluten in a dough.

Did You Know That …

Legumes have the ability to naturally enrich the soil with nitrogen.
Consuming legumes has been reported to decrease the risk of certain types of cancer.
Legume flours are packed with nutrients and fiber.
Legume flours contain twice as much protein as wheat flour.
Legume flours are naturally gluten-free.
Legumes offer significant agricultural advantages, both as an important part of crop rotation and due to their low need for nitrogen fertilizers.

Legume flours have a higher ability to absorb water than wheat flour, which can potentially improve the shelf life of products.

Could legume flours be the future alternative to wheat flour?

Still, the incorporation of legume flours into products normally made with wheat flour can influence the appearance, smell, taste, and texture of the product. In a pilot sensory test conducted at Axfoundation, participants were asked to rate the appearance, smell, taste, and texture of legume flours baked products made from Swedish brown bean, fava bean, and yellow pea flour.

While the participants noted differences in aroma, taste, and texture brought by the legumes, the results were promising: there were no significant differences in preference compared to the purely wheat-based product, signaling real potential for further development. Whereas the products made from yellow peas were appreciated for their similar look, taste, and smell to wheat flour products, the fava bean and brown bean products were appreciated for their ‘healthy look,’ reminding of a whole grain wheat flour baked product.

Participants indicated that healthiness, taste, and environmental sustainability were the most important unique selling points to them. With further refinement legume products could be created that answer all three of these unique selling points: a product that not only tastes great but also supports both human health and environmental sustainability. The future looks bright for legume-based foods!

// Birte van Ittersum holds an MSc in food technology, nutrition and gastronomy at Wageningen University in the Netherlands