Abstract: The conversion factor of percent nitrogen to percent protein in rice protein was determined by amino acid contentanalysis of ten samples obtained from different areas. The nitrogen contents of amino acid in 10 samples were almost same(N=13.48%, S=0.19, CV=1.4%). Considering the variations of the contents of asparagine (Asn) and glutamine (Gln) in riceprotein, and with the analysis of all compositions in high purity rice protein isolate (RPI), the conversion factor was determinedto be 6.70, which was then verified to be credible.

Key words: rice protein isolate, conversion factor, amino acid content analysis