Cereal Chem 57:94 - 96.  |  VIEW ARTICLE
Chlorine Treatment of Cake Flours. V. Oxidation of Starch.

A. C. Johnson, R. C. Hoseney, and K. Ghaisi. Copyright 1980 by the American Association of Cereal Chemists, Inc. 

Starches isolated from untreated flour and from Cl2-treated flour performed equally well in cakes baked from reconstituted flours when the untreated starch was air-dried. Freeze-dried starch isolated from untreated flour gave results equal to results with untreated flours. Vacuum-drying or solvent-drying of the starch gave results similar to freeze-drying. Thus wetting and air-drying starch appeared to be equivalent to Cl2-treatment as far as cake-baking performance was concerned. Surprisingly, commercial wheat starch responded to the wetting and drying treatment similarly to laboratory-isolated starch. Treatment of starch with base, to remove protein, reduced the effectiveness of air-drying. However, the baking quality of starch that had previously been air-dried was not affected by treatment with base. Treatment of good baking quality starches (air-dried and Br2-treated) with beta-amylase showed that they were depolymerized compared with poor-baking-quality starch (freeze-dried). Starches were debranched with pullulanase and separated into amylose and debranched amylopectin fractions by gel filtration. Both fractions from good baking quality starches (air-dried and Br2-treated) gave lower beta-amylolysis values than did the poor baking quality starch (freeze-dried). This indicates that the improving action of oxidative agents (Cl2, Br2, and air-drying) consists of oxidative depolymerization and probably oxidation of glucose residues in the starch chains.