Table 1.
Characteristics of commonly available protein sources1,2
| WPI | WPC | Casein | SPI | RPC | PPC | |
|---|---|---|---|---|---|---|
| ∑ IAA, g/25 g protein | 12.4 | 11.7 | 11.0 | 9.0 | 6.7 | 5.9 |
| ∑ BCAA, g/25 g protein | 5.6 | 5.4 | 4.9 | 3.4 | 3.3 | 2.6 |
| Leucine, g/25 protein | 3.0 | 2.5 | 2.3 | 1.5 | 1.5 | 1.4 |
| DIAAS score | 1.09 | 0.97 | ND | 0.90 | 0.37 | 0.82 |
1WPI, whey protein isolate; WPC, whey protein concentrate; SPI, soy protein isolate; RPI rice protein concentrate; PPC, pea protein concentrate; IAA, indispensable amino acid; BCAA, branched-chain amino acid; ND, not determined.
2amino acid content can be found in the USDA National Nutrient Database for Standard Reference—http://ndb.nal.usda.gov/ (United States Department of Agriculture). DIAAS scores from Rutherfurd et al. (2015).