Pulses part 3: soybeans Soybeans (soya beans) are slightly different to other pulses. Whereas the others lack methionine, soybeans contain a certain amount of it, thus having all the essential eight amino acids needed to form protein. They are therefore useful in vegetarian and vegan diets. Also, their fat contains beneficial omega-3 oils, and their isoflavones may aid bone density and even protect against cancer.