Cereal Chem 64:384-389   |  VIEW ARTICLE

Effect of Tortilla Production on Proteins in Sorghum and Maize.

N. E. Vivas, R. D. Waniska, and L. W. Rooney. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

The solubility and molecular weight distribution of sorghum and maize proteins were determined during tortilla preparation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis patterns were obtained for four protein fractions (albumin and globulin, prolamins, alcohol-soluble reduced glutenins, and glutenins) from raw grain, nixtamal, masa, and tortilla samples of sorghum and maize. Alkaline processing decreased the solubility of proteins in salt water and alcohol and increased the amount of unextractable proteins. The number and intensity of protein bands in the electrophoretic patterns changed after processing for both grains, with more changes observed in sorghum than in maize samples. Prolamins were more efficiently extracted with 60% tert-butyl alcohol than with 70% isopropyl alcohol. Pepsin digestibility of protein in sorghum and maize samples decreased after processing, with sorghum having slightly lower digestibilities than maize. Processing sorghum and maize into tortillas significantly affected protein solubility and structure.