Soy – properties, nutritional value, application, and potential adverse effects

The most extensively cultivated soybean variety is vegetable soybean, scientifically designated as *Glycine max* (L.) Merr., an annual leguminous plant originating from Southeast Asia. Its cultivation history in China spans **four millennia**, underscoring its enduring agricultural significance. Presently, the **United States** and **Brazil** dominate global production, with vast monocultures dedicated to this crop. The surge in its popularity over recent decades is largely attributable to the expanding adoption of plant-based diets—both vegan and vegetarian—as soy represents one of the **few complete plant-based protein sources**, furnishing all essential amino acids in balanced proportions. With regard to protein quality, the **Protein Digestibility-Corrected Amino Acid Score (PDCAAS)** for soy protein isolate attains the **maximum value of 1.00**—equivalent to that of chicken egg protein—whereas whole soybeans achieve a score of **0.91**. Meanwhile, the **biological value (BV)** of soy protein stands at **74**, while that of whole soybeans reaches **96** (compared to **97** for chicken eggs). Beyond its protein content, soy is a rich source of **polyunsaturated fatty acids**, including linoleic acid (omega-6) and α-linolenic acid (omega-3), as well as B-complex vitamins such as thiamine (B₁), riboflavin (B₂), and folic acid (B₉). A nutritional breakdown reveals that **100 grams of dried soybeans** fulfill daily requirements for the following minerals: **potassium** at **45%**, **calcium** at **24%**, **phosphorus** at an exceptional **106%**, **magnesium** at **54%** (for men) or **70%** (for women), and **iron** at **89%**, positioning it among the most nutrient-dense legumes available commercially.