In this paper, a simple method of determining the content of protein is given. The fundamental principle of determining its content is that of the decomposition of protein through digestion of the food by adding sulphuric acid. The ammonium sulfate is formed due to the combination of decomposed ammonia and the sulphuric acid . The content of dissociated ammonia in the sample liquid can thus be determined by using ammonium electrode and the contnet of protein in food can be obtained after conversion.
