Cereal Chem 64:15-20   |  VIEW ARTICLE

Improvements in Wheat Protein Analysis and Quality Prediction by Reversed-Phase High- Performance Liquid Chromatography.

F. R. Huebner and J. A. Bietz. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

Specific problems in wheat gluten protein analysis by reversed-phase high-performance liquid chromatography (RP-HPLC) and in evaluating data for predicting quality were found. Procedures were developed to improve the method's reliability and reproducibility. To obtain accurate integration, a flat baseline is desirable; this was achieved by reducing (15-18%) the concentration of trifluroacetic acid in acetonitrile. The similarity of gliadins extracted with 50 or 70% ethanol or after pre-extraction with 0.1M NaCl was demonstrated; adjustment of extractant hydrophobicity prevented early elution of gliadins during preparative RP-HPLC. Long-term storage of gliadins at various temperatures was studied; -70 C is recommended. Various dissociating solvents for extraction, reduction, and alkylation of glutenin were compared, and the need for acidification following alkylation for long-term storage was demonstrated. We also demonstrated that computer analyses of chromatographic data can identify proteins correlated with quality.