GLIADIN EXTRACTION FOR REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - AN ASSESSMENT OF METHODOLOGY

Gliadins from Triticum durum DESF. and Haynaldoticum sardoum MELETTI & ONNIS (Poaceae) were directly extracted with 70 % ethanol or preextra cted with 0.5 M NaCl to remove albumins and globulins. The extracts we re chromatographed on a reversed-phase column and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both analyses show ed that the gliadin fraction directly extracted with ethanol contains additional early-eluting proteins upon reversed-phase high performance liquid chromatography, and low M(r) electrophoresis bands. The early- eluted proteins were collected, concentrated and electrophoresed. Resu lts showed that they are salt soluble protein contaminants of gliadin. We thus advise that cereal meals should be pre-extracted with NaCl pr ior to prolamin analysis by reversed-phase high performance liquid chr omatography