Is quinoa a complete protein, meaning does it contain all nine essential amino acids in sufficient quantities, and how does its amino acid profile compare to other plant-based protein sources like beans, lentils, or nuts, specifically regarding lysine and isoleucine content, and how does its protein digestibility-corrected amino acid score (PDCAAS) compare to these other sources and to animal protein sources?

Answer

Yes, quinoa is considered a complete protein.

A complete protein contains all nine essential amino acids in sufficient quantities. These amino acids are:

* Histidine
* Isoleucine
* Leucine
* Lysine
* Methionine
* Phenylalanine
* Threonine
* Tryptophan
* Valine

The human body cannot synthesize these amino acids, so they must be obtained through diet. Quinoa naturally contains all of these essential amino acids, making it a valuable plant-based protein source. The amino acid profile of quinoa is well-balanced, meaning the ratios of the different amino acids are also favorable for human needs. This is unlike many other plant-based proteins, which are often lacking or low in one or more essential amino acids. For example, lysine is often limited in grains, but quinoa contains a good amount.