ACID-SOLUBLE PROTEINS OF WHEAT FLOURS .2. BINDING TO HYDROPHOBIC GELS

Binding of acid-soluble proteins from untreated and defatted good (Shawnee, C.I. 14157) and poor (Chiefkan/Tenmarq, KS501097) baking quality flours to Phenyl-Sepharose CL-4B was examined by batch-elution and column-elution techniques. When a mixture of hydrophobic gel and acid-soluble flour proteins was eluted batchwise with 5 solvents, total absorbance at 280 nm of the eluates was higher for the poor than for the good baking quality flour. Acid-soluble proteins of defatted good and poor baking flours differed little from those of nondefatted flours in hydrophobic binding capacity. Glutenins from isopropanol-defatted poor baking quality flour (KS501097) were less hydrophobic, and gliadins were more hydrophobic, than glutenins and gliadins from the good baking quality flour. The difference in apparent hydrophobic interaction was more pronounced for glutenin than for gliadin. The relation between the amount of protein eluted and the amount of protein adsorbed by the hydrophobic gel varied with protein sources and their concentrations. Among protein eluting agents, 1% sodium dodecyl sulfate in 0.01 N acetic acid was most effective. Acid-soluble proteins from good and poor bread-making flours differ in apparent hydrophobic properties.