Influence of Heating on the Liberation of Certain Amino Acids from Whole Soybeans.

Summary A study was made on the effect of boiling on the liberation of amino acids by acid and enzymatic hydrolysis using microbiological assay methods. Boiling up to 12 hours did not not affect the release by acid hydrolysis of α-amino nitrogen and of 7 essential amino acids studied. Boiling for 15 minutes caused a slight increase in the release of α-amino nitrogen and amino acids by pancreatic digestion but boiling for 1 hour and longer up to 12 hours resulted in a marked increase. The increase in the enzymatic liberation of amino acids for periods of over one hour was about twice that liberated from raw soybean. Prolonged boiling up to 12 hours with definite browning did not result in a decrease in enzymatic liberation of amino acids from the “overcooked” soybean.