The study found that the nutritional value of meat substitutes currently on the market is based on factors such as raw material selection (often imported soybeans), processing methods (anti-nutrient content), and added ingredients (fat quality). and salt).
As more people adopt a plant-based diet, the rise of plant-based protein options as meat substitutes has increased significantly. However, the nutritional value of these products remains a concern. A study from Chalmers University of Technology in Sweden found that many meat substitutes sold in Sweden are high in iron, but in a form that is not absorbed by the body.
Ann-Sofie Sandberg Professor, Department of Biology and Biotechnology, Chalmers Institute of Technology. Credit: Chalmers
A diet consisting primarily of plant foods such as roots, legumes, fruits and vegetables generally has a lower climate impact and health benefits such as reduced risk of age-related diabetes and cardiovascular disease. Also related to shown in several large-scale studies. However, there is far less research into how people’s health is affected by eating products based on what are known as texture plant proteins.
In a new Chalmers study, researchers from the Department of Food and Nutritional Sciences analyzed 44 different meat substitutes sold in Sweden. The product is made primarily from soy and pea proteins, but it also contains the fermented soy products tempeh and mycoprotein, which are proteins from fungi.
“Among these products there was wide variation in nutritional content and sustainability in terms of health. In general, the estimated absorption of iron and zinc from the products was very low. This is because these meat substitutes contain high levels of phytate, an anti-nutrient that inhibits the absorption of minerals in the body,” says Cecilia Meyer Rabba, lead author of the study. base protein.
Lack of minerals needed by the body
Phytates are found naturally in beans and grains. It accumulates when protein is extracted for use in meat substitutes. In the gastrointestinal tract, where mineral absorption takes place, phytic acid forms insoluble compounds with essential dietary minerals, especially nonheme iron (iron found in plant foods) and zinc.
“Both iron and zinc also accumulate in protein extracts. This is why high levels are listed in the ingredients of the product, but the mineral is bound to phytic acid and can be absorbed and used by the body.” No,” said Cecilia Mayer Labba.
Cecilia Mayer Labba PhD, Department of Biology and Biotechnology, Chalmers Institute of Technology. Credit: Martina Butorac/Chalmers
Iron deficiency in women is a widespread global problem. In Europe, it affects 10–32% of her women of childbearing age, and in Sweden it affects her 1 in almost 3 of her teenage girls who attend secondary school. Women are also the group in society most likely to switch to a plant-based diet and minimize the amount of red meat, which is the main source of easily absorbed iron in the digestive tract.
“When it comes to minerals in meat substitutes, it’s clear that how much your body can absorb is a very important consideration. Fortified with phytate, it is still inhibited by phytate. I believe,” said Anne-Sophie Sandberg, a professor of food and nutritional sciences at Chalmers and co-author of the study. .
The food industry needs new ways
Tempeh, made from fermented soybeans, differed from other meat substitutes in the amount of iron that the body could absorb. Mycoprotein did not contain any known anti-absorption substances and stood out for its high zinc content. And how this affects nutrient absorption is still unknown.
“Plant-based foods are important for the transition to sustainable food production, and plant-based meat alternatives have great development potential. We need to not only utilize and optimize our process technology, but also develop new ways to enhance the absorption of a range of key nutrients,” says Cecilia Meyer Rabba.
Vegetable protein production
- Most existing plant-based protein products on the market are based on proteins that have been extracted from cultivated plants such as soybeans and separated from the other components of the plant.
- The protein is then subjected to high pressure and temperature, known as texturization, to restructure the protein so that it can be combined with other ingredients to achieve a meatier, chewier product.
- According to Chalmers’ research, the nutritional value of currently available meat substitutes depends on the choice of raw materials (often imported soybeans) and processing conditions (anti-nutrient content), as well as additives (fat quality and salt content). It is often inadequate.
- A meal containing 150 grams of meat substitutes corresponds to 60% of the maximum recommended daily salt intake. This is 6 grams according to the Nordic Nutrition Recommendations.
Reference: “Nutritional Composition and Estimated Iron and Zinc Bioavailability of Meat Alternatives Available on the Swedish Market”, Inger-Cecilia Mayer Labba, Hannah Steinhausen, Linnéa Almius, Knud Erik Bach Knudsen, Ann-Sofie Sandberg, September 2022 21 days, nutrients.
DOI: 10.3390/nu14193903
This study was funded by the Bertebos Foundation, the Swedish Research Council Formas, and the Vestra Gotaland Region.
