Cooking procedures for direct consumption of whole soybeans

The purpose of this research was to determine adequate conditions for the preparation of soybeans at home level. In accordance with the results, soaking the soybeans for eight hours in a 0.25% bicarbonate solution, gives the appropriate hydration to the soybeans, which can then be easily cooked. Boiling them at atmospheric pressure during 20 minutes was required to destroy 80% of the soybeans antitrypsin activity, and a high PER was also obtained. Nevertheless, the soybeans texture was not satisfactory; therefore, longer boiling periods were tested so as to establish the most suitable time needed to achieve a softness similar to that of common beans as usually consumed. Softness was measured instrumentally, and the optimal conditions found were: 40 min boiling after 8 hr soaking in a 0.25% bicarbonate solution. Under these conditions, the PER and NPU values increased 18% and 33%, respectively, with respect to those of the casein PER and NPU. It is concluded that with this procedure, large amounts of protein can become available at an equivalent price to US$0.40/kg ($80.00/kg).