Cereal Chem. 70:448- 452   |  VIEW ARTICLE

Partially Purified Proteolytic Enzymes from Wheat Flour and Their Effect on Elongational Viscosity of Cracker Sponges.

W. D. A. Lin, G. Lookhart, and R. C. Hoseney. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

Enzymes were extracted from wheat flour with ammonium sulfate and purified by gel-filtration chromatography. Two peaks of proteolytic activity were detected. Lubricated uniaxial compression was used to measure the changes in elongational viscosities of cracker sponges at pH 4 during fermentation. The elongational viscosities of the sponges decreased with fermentation time, indicating enzyme activity. The elongational viscosities of the sponges were not noticeably changed when the enzymes had been extracted from the flour. However, the elongational viscosities of the sponges again decreased with fermentation time when the extracted enzymes were added back to the flour. Only one of the two proteolytically active fractions eluted from Sephadex G-100 was responsible for the change in the elongational viscosity of the sponge during fermentation. Rechromatography was used to further purify the proteolytic enzyme and produce a single peak with high specific proteolytic activity. Since pepstatin inhibited most of the activity of the purified enzyme preparation, it contains an acid protease.