Myth busted: processed soy is no less nutritious

As an increasing number of consumers have embraced veganism and vegetarianism (or chosen, at least, to reduce their reliance on animal foods), all sorts of nutritious pulses have sparked their interest, one of the most notable being protein-rich soya beans, and particularly processed soy products.

A popular belief persists that processing soya beans decreases their protein nutritional quality, so scientists from Unilever and Wageningen University and Research in the Netherlands recently set out to challenge negative perceptions by looking at processed soy, an ingredient Unilever uses in some of its food brands.

The results of the study⁰¹ were quite revealing. As Amelia Jarman, Unilever’s Future Health & Wellness Science and Technology Director, explains: ‘For the first time, a study comprehensively finds that the protein quality of soy used in our plant-based foods is not compromised during processing, contrary to misconceptions. In fact, processing soy slightly increases the protein’s nutritional quality.’

‘Given the rising demand from environmentally conscious consumers looking to transition away from meat but still looking for nutritious, high-quality food, this research is very exciting as it proves that meat-free alternatives actually do fulfill our bodies’ protein requirements.’

What is soy?

Soya beans are the seeds of a legume indigenous to East Asia, where they have been cultivated since ancient times. They contain all nine essential amino acids necessary for human nutrition, comprising 38 grams of protein per 100 grams, which is more than three times that of an egg. Interestingly, soya beans deliver more protein per hectare than any other major crop. They’re rich in other nutrients (including B vitamins, calcium, magnesium, and potassium), high in fibre, and low in fat, making them a great choice for plant-based diets in all their forms, including soy milk, oils, flours, pastes, sauces, tofus, and textured vegetable proteins.

Processing soya beans

Soy is a common ingredient in plant-based foods because of its high protein content and quality. But you can’t simply add soya beans in their natural form to, for example, a plant-based ‘chicken’ chunk or ice cream. Before being used, the beans must undergo processing, which can take various forms including soaking, heating, and dehulling.

To better understand the effect of processing on protein quality, the study mentioned above assessed the digestibility indispensable amino acid scores (DIAAS), which are the Food and Agriculture Organization of the United Nation’s standard measure of various products. The higher the score, the better the protein source fulfills our body’s requirements, with a score of 75 or above considered good.

Analysis of the data showed different protein quality scores between soy product groups, but the DIAAS score for soy protein concentrate was 88, which is slightly higher than the soya bean in its unprocessed form (which scores 85).

This research confirms that soy ingredients used in plant-based food products can be a good source of protein and just as good as the protein quality of soya beans.

Making healthier and plant-based options accessible to all

It has been known for some time that the world cannot sustainably feed itself at the rate we’re going – there is clearly a pressing need for meat and dairy alternatives.

In 2020, Unilever committed to helping people transition to a plant-based way of eating that’s healthier for them and for the planet through our Future Foods commitment.

The knowledge we’ve gained from this latest research will help us to reach our sustainability commitments and to develop innovative new plant-based foods. It’s a stretching ambition but an achievable one, given that the move towards plant-based foods continues to gather speed.

Plant-based alternatives give consumers a simple way to transition to more sustainable diets. As Hanneke Faber, Unilever’s President, Global Nutrition, says: ‘It’s not up to us to decide for people what they want to eat, but it is up to us to make healthier and plant-based options accessible to all’.

Try our Knorrox soya mince

One of Unilever’s best-loved South African brands, Knorrox, offers a range of versatile, affordable soy-based mince products which are rich in protein and fortified with zinc. They’re a great alternative to beef in lasagnes, curries, stews, and bakes, and for making a little go a long way!

Here are some easy recipes perfect for nutritious family dinners:

Knorrox Soya Mince Lasagne

Spicy Soya Mince with Samp and Beans

Knorrox Roasted Butternut Stuffed with Soya Mince

Chilli Mince with Vetkoek