The Study
True ileal amino acid digestibility and digestible indispensable amino acid scores (DIAASs) of plant-based protein foods.
This study measured how well minipigs digested different plant foods, like tofu and seitan, but it didn't test if those foods make people healthier or stronger. So we can only say what happened in pigs — not what will happen in humans.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists tested how well the body can use protein from plant foods like tofu, soya milk, seitan, and pea pudding by feeding them to mini-pigs and checking what gets absorbed.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 518 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Even though tofu and soya milk come from the same beans, tofu’s gel structure makes some amino acids harder to digest, lowering its protein quality score compared to liquid soya milk.
- 2All four foods had 92–97% protein digestibility—similar to meat and milk.
- 3But soya milk scored 117% on protein quality (DIAAS), tofu scored 97%, pea pudding scored 42–64%, and seitan scored only 20–31% because it lacks lysine.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Food chemistry
Year
2020
Authors
Yohan Reynaud, C. Buffière, Benoît Cohade, Mélissa Vauris, Kevin Liebermann, Noureddine Hafnaoui, Michel Lopez, I. Souchon, D. Dupont, D. Rémond
Related Content
Claims (6)
Tofu contains all essential amino acids in better proportions than most plant proteins, but the body absorbs fewer of those amino acids from tofu than from eggs, meat, or dairy.
Seitan provides only 20–31% of the essential amino acids needed by adults because it lacks sufficient lysine, even though the protein in seitan is easily digested.
In minipigs, the digestibility of amino acids from seitan, tofu, soya milk, and pea emulsion is between 92% and 97% and does not differ significantly between these plant-based foods, showing that processing them into whole foods does not substantially reduce amino acid absorption.
Soya milk provides more usable essential amino acids than tofu, even though both are made from the same soy source, because the body absorbs sulphur-containing amino acids more efficiently from soya milk than from tofu.
Pea emulsion provides a moderate amount of essential amino acids that the human body can absorb, with sulphur-containing amino acids being the least available, even though most other amino acids are well digested.
When sulphur-containing amino acids are delivered in a gel form like tofu versus a liquid form like soya milk, their digestion in minipigs is different, even when the same protein is used in both forms.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.