Cereal Chem 54:882 - 894.  |  VIEW ARTICLE
Changes in Semolina Proteins During Spaghetti Processing.

J. E. Dexter and R. R. Matsuo. Copyright 1977 by the American Association of Cereal Chemists, Inc. 

Three durum wheats of widely differing spaghetti cooking quality and a hard red spring wheat were processed into spaghetti in a DeMaco laboratory extruder. Samples were taken at various stages throughout the spaghetti-making process and were analyzed for sulfhydryl group and disulfide bond contents. For all four wheats, there was a substantial loss of sulfhydryl groups by the extrusion stage, although, by far, the greatest portion of the loss occurred during the first 6 hr of the 29-hr drying cycle. No relation could be established between cooking quality and the extent of sulfhydryl group loss. Disulfide bond levels did not change significantly during processing for any of the wheats. Changes in protein solubility during spaghetti- making followed a similar pattern for all four wheats. In each case, protein extractability in dilute acetic acid had decreased substantially by the time the dough entered the extruding auger. No further change in solubility occurred during the remainder of processing. Osborne solubility fractionations disclosed an increase in the amount of insoluble residue protein concomitant with a decrease in the amount of salt- soluble protein. Gel filtration elution profiles on Sephadex G-150 in AUC showed no significant changes in the molecular weight (MW) distribution of the proteins during spaghetti processing. This in conjunction with electrophoretic results, which revealed no qualitative changes in protein electrophoretic patterns during spaghetti processing, suggested that the loss of salt-soluble proteins may be due to binding by the insoluble components of the semolina rather than by polymerization.