The provision of meals based mostly on plant proteins to substitute for meat has elevated dramatically as extra folks select a plant-based food plan. On the similar time, there are various challenges concerning the dietary worth of those merchandise. A research from Chalmers now exhibits that lots of the meat substitutes offered in Sweden declare a excessive content material of iron – however in a kind that can not be absorbed by the physique.
A food plan largely made up of plant-based meals equivalent to root greens, pulses, fruit and greens typically has a low local weather influence and can be related to well being advantages equivalent to a decreased danger of age-related diabetes and heart problems, as has been proven in a number of giant research. However there have been far fewer research of how folks’s well being is affected by consuming merchandise based mostly on what are referred to as textured* plant proteins.
In the new study from Chalmers, a analysis workforce within the Division of Meals and Diet Science analysed 44 completely different meat substitutes offered in Sweden. The merchandise are primarily manufactured from soy and pea protein, but in addition embrace the fermented soy product tempeh and mycoproteins, that’s, proteins from fungi.
‘Amongst these merchandise, we noticed a large variation in dietary content material and the way sustainable they are often from a well being perspective. Normally, the estimated absorption of iron and zinc from the merchandise was extraordinarily low. It’s because these meat substitutes contained excessive ranges of phytates, antinutrients that inhibit the absorption of minerals within the physique,’ says Cecilia Mayer Labba, the research’s lead creator, who just lately defended her thesis on the dietary limitations of switching from animal protein to plant-based protein.
The physique misses out on necessary minerals
Phytates are discovered naturally in beans and cereals – they accumulate when proteins are extracted to be used in meat substitutes. Within the gastrointestinal tract, the place mineral absorption takes place, phytates kind insoluble compounds with important dietary minerals, particularly non-heme iron (iron present in plant meals) and zinc, which implies that they can’t be absorbed within the gut.
‘Each iron and zinc additionally accumulate in protein extraction. This is the reason excessive ranges are listed among the many product’s components, however the minerals are sure to phytates and can’t be absorbed and utilized by the physique,’ says Cecilia Mayer Labba.
Iron deficiency amongst ladies is a widespread, world drawback. In Europe, 10 to 32 per cent of ladies of childbearing age are affected and nearly one in three teenage women at secondary college in Sweden***. Girls are additionally the group in society most certainly to have switched to a plant-based food plan and to eat the least quantity of crimson meat, which is the primary supply of iron that may be simply absorbed within the digestive tract.
‘It’s clear that with regards to minerals in meat substitutes, the quantity that’s accessible for absorption by the physique is an important consideration. You can not simply take a look at the checklist of components. A few of the merchandise we studied are fortified with iron however it’s nonetheless inhibited by phytates. We consider that making diet claims on solely these vitamins that may be absorbed by the physique may create incentives for the business to enhance these merchandise,’ says Ann-Sofie Sandberg, Professor of Meals and Diet Science at Chalmers and co-author of the research.
The meals business wants new strategies
Tempeh, constructed from fermented soybeans, differed from the opposite meat substitutes within the quantity of iron accessible for absorption by the physique. This was anticipated, because the fermentation of tempeh makes use of microorganisms that break down phytates. Mycoproteins stood out for his or her excessive zinc content material, with out containing any identified absorption inhibitors. Nonetheless, based on the researchers, it’s nonetheless unclear how nicely our intestines can break down the cell partitions of mycoprotein how this in flip impacts the absorption of vitamins.
‘Plant-based meals is essential for the transition to sustainable meals manufacturing, and there may be big improvement potential for plant-based meat substitutes. The business wants to consider the dietary worth of those merchandise and to utilise and optimise identified course of strategies equivalent to fermentation, but in addition develop new strategies to extend the absorption of varied essential vitamins,’ says Cecilia Mayer Labba.
Textual content: Susanne Nilsson Lindh & Karin Wik
Picture: Unsplash
Manufacturing of plant proteins
- Most present plant-based protein merchandise in the marketplace are based mostly on protein extracted from a cultivated plant, equivalent to soybeans, and separated from the plant’s different parts.
- The protein is then subjected to excessive strain and temperature, which restructures the proteins, referred to as *texturization, so {that a} product could be achieved that’s meatier and chewier together with different components.
- Chalmers’ research exhibits that the dietary worth of meat substitutes accessible right this moment is usually poor relying on the selection of uncooked materials (typically imported soy) and processing situations (content material of anti-nutrients), and on components (fats high quality and salt).
- A meal containing 150 grams of meat substitutes contributes as much as 60% of the utmost really useful day by day consumption of salt, which based on the Nordic Diet Suggestions is 6 grams.
* The protein is restructured by excessive strain and temperature.
** Milman, Taylor, Merkel and Brannon: Iron standing in pregnant ladies and girls of reproductive age in Europe. Am J Clin Nutr 2017; 106 (Suppl): 1655S-62S.
*** Riksmaten Adolescents Survey 2016-2017, Swedish Nationwide Meals Company (Livsmedelsverket) report sequence no. 23, 2018. Swedish Nationwide Meals Company (Livsmedelsverket) 2018.
