Cereal Chem 72:275-280  |  VIEW ARTICLE

Characterization and Digestibility of Basmati Rice (Oryza sativa L. var. Dehraduni) Storage Proteins.

D. F. Steenson and S. K. Sathe. Copyright 1995 by the American Association of Cereal Chemists, Inc. 

Polished Basmati Dehraduni (BD) rice contained 9.5 +/- 0.1% protein (N x 6.25). Albumin, globulin, prolamin, and glutelin fractions accounted for 5.9, 13.8, 5.8, and 74.5% of the total protein, respectively. All four protein fractions showed high amounts of glutamic acid, aspartic acid, and alanine. Threonine was the first limiting amino acid in all the protein fractions and the total rice proteins. The major polypeptides in albumin, globulin, prolamin, and glutelin had estimated molecular masses of 14.1 kDa; 13.9, and 20.3 kDa; 13.6 kDa; and 20.4 and 30.9 kDa, respectively. For each protein fraction there was a positive correlation between in vitro enzymatic digestion time and the extent of polypeptide hydrolysis. Electrophoresis gels of time-course digestions for each fraction revealed more extensive hydrolysis of polypeptides by pepsin than by trypsin, with accelerated hydrolysis rates in the heated protein. Albumin and globulin were most easily hydrolyzed by pepsin and trypsin, while prolamin was the most resistant to in vitro enzymatic digestion.