Nine amino acids must come from food
Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine are indispensable in adult diets. In one six-protein comparison, the tested yeast isolate contained 508 mg of indispensable amino acids per gram of protein and about 98.6 mg leucine per gram.
These are four different things. That same study measured lower true and ileal digestibility for its yeast ingredient than for the comparison proteins. The careful conclusion is that yeast protein can provide a strong, complete profile while availability varies by preparation.
Evaluation of the nutritional quality of yeast protein in comparison to animal and plant proteins using growing rats and INFOGEST model
Yeast protein had a strong indispensable-amino-acid profile, but lower measured true protein and ileal amino-acid digestibility than comparison proteins in this experiment.
- Model
- Growing rats and a standardized laboratory digestion model
- Sample
- Preclinical experiment
- Intervention
- Yeast protein isolate · Study-specific
- Comparator
- Whey concentrate/isolate, soy, wheat and pea isolates
Cao X, Liu H, Yang M, Mao K, Wang X, Chen Z, Ran M, Hao L · 2025 · Food Chemistry
DOI 10.1016/j.foodchem.2024.141178 ↗View references (1)
- Cao X, Liu H, Yang M, Mao K, Wang X, Chen Z, Ran M, Hao L. (2025). Evaluation of the nutritional quality of yeast protein in comparison to animal and plant proteins using growing rats and INFOGEST model. Food Chemistry. https://doi.org/10.1016/j.foodchem.2024.141178