What is the highest quality plant protein source?

Soybeans are considered to be the highest quality plant protein source, containing all the essential amino acids that the human body cannot produce on its own. Soy protein is a complete protein, meaning it contains a well-balanced profile of amino acids, including a high proportion of lysine, which is often deficient in other plant proteins. With a Protein Digestibility-Corrected Amino Acid Score (PDCAAS) of 1.0, soybeans are recognized for their high-quality protein content and digestibility. Soybeans and soy-derived products, such as tofu, tempeh, and edamame, are widely consumed worldwide as a valuable plant-based alternative to animal proteins.