Essential amino acids
Legumes are known for their good ratio of essential amino acids, which our own body cannot produce itself. The ratio of essential amino acids of the proteins in egg is often used as a reference, because it is complete for what we need on a daily basis.
When we compare 100 grams of faba beans with 100 grams of egg, we see that the content of all essential amino acids in faba beans is higher than in egg, except for the sulfur-containing methionine. This is mainly because faba beans have a higher protein content than egg. Faba beans have a high content of leucine, the amino acid that plays a crucial role in muscle growth.
Per gram of protein, faba beans have a similar content of essential amino acids as that of egg. This does not apply to the sulphur-containing methionine, which, together with the also sulphur-containing cysteine, is roughly half that of egg. Methionine and cysteine are more represented in grains and rice, which indicates the importance of a balanced diet.
In that respect, our distant ancestors had done well with their meals of bread or rice with legumes, which provided a sufficient supply of all the necessary essential amino acids. Without ever having heard of proteins. So not surprising.
Would you like an overview of the protein composition of faba beans?