The research team found beef contained 22 metabolites that the plant substitute did not. In contrast, the plant-based substitute contained 31 metabolites that meat did not.
The largest discrepancies occurred in amino acid, dipeptide, vitamin, phenol, and saturated and unsaturated fatty acid levels found in these products.
Writing in Scientific Reports, the Duke University research team highlights that many nutrition components do not appear on plant substitute labels.
“To consumers reading nutritional labels, they may appear nutritionally interchangeable," said study lead author Stephan van Vliet, a postdoctoral researcher at the Duke Molecular Physiology Institute.
"But if you peek behind the curtain using metabolomics and look at expanded nutritional profiles, we found that there are large differences between meat and a plant-based meat alternative."
Using metabolomic techniques, the team compared 18 samples of a popular plant-based meat alternative to 18 grass-fed ground beef samples.
The analysis of these 36 cooked patties found that 171 out of the 190 list of metabolites they measured varied between beef and the plant-based meat substitute.
Several ‘important’ metabolites were found either exclusively or in greater quantities in beef, including creatine, spermine, anserine, cysteamine, glucosamine, squalene, and the omega-3 fatty acid DHA.
Multiple health roles
"These nutrients have potentially important physiological, anti-inflammatory, and or immunomodulatory roles," the authors said in the paper.
“Low intakes are associated with cardiovascular, neurocognitive, retinal, hepatic, skeletal muscle, and connective tissue dysfunction,” they add.
"These nutrients are important for our brain and other organs including our muscles" van Vliet comments. "But some people on vegan diets (no animal products), can live healthy lives -- that's very clear."
According to market research firm Statistica, the global plant-based meat alternative sector has experienced substantial growth and is projected to increase from €9.8bn ($11.6bn) in 2019 to €26bn ($30.9bn) by 2026 with a compound annual growth rate (CAGR) of 15%.
In contrast, the meat sector is expecting a CAGR of 3.9% during this time and to reach a market value of €962bn ($1142.9bn) by 2023.
The demand has led to a new generation of plant-based meat alternatives such as the Impossible Burger and Beyond Burger.
Their success has led other international food companies—including traditional meat companies—to invest in their own product versions.
These companies include Tyson, Smithfield, Perdue Farms, Hormel Foods, and Maple Leafs, who have all joined the alternative meat market, developing their own brands of plant-based products.
Advances in meat alternatives
Recent developments in the field include microalgae proteins extracted from Spirulina and proteins isolated from insects.
Proteins synthesised in vitro and mycoproteins produced by fungal fermentation have the advantage of forming elongated fibres, mimicking a meat-like chewable characteristic.
However, due to the high production cost, projected climate impacts, and other factors, both alternative proteins are still under development or further improvement.
In comparison, plant proteins can be utilised directly to construct meat-like alternatives. Hence, plant-based meat alternatives, substitutes, or replacements represent a primary sector of this emerging and rapidly evolving industry.
"It is important for consumers to understand that these products should not be viewed as nutritionally interchangeable, but that's not to say that one is better than the other," said van Vliet, "Plant and animal foods can be complementary, because they provide different nutrients."
In concluding the study, the team suggests future studies that better understand how metabolites and nutrients in plant-based meat alternatives and meat impacts short- and long-term consumer health.
Studies performed on children, elderly, those with metabolic disease and in response to plant-based meat alternatives are recommended to evaluate their role in the human diet.
Source: Sci Rep
Published online: doi.org/10.1038/s41598-021-93100-3
“A metabolomics comparison of plant-based meat and grass-fed meat indicates large nutritional differences despite comparable Nutrition Facts panels.”
Authors: van Vliet et al