Cereal Chem 49:532 - 543. | VIEW
Effect of Bread Ingredients on Starch-Gelatinization Properties as Measured by the Amylograph.
B. L. D'Appolonia. Copyright 1972 by the American Association of Cereal Chemists, Inc.
The Brabender Amylograph was used to study the gelatinization properties of starch in the presence of ingredients commonly used in bread production. Effects of the addition of sugar (sucrose); salt (sodium chloride); nonfat dry skim milk; shortening; oxidizing agents; reducing agents; and a mold inhibitor, sodium propionate, on the pasting properties of starch at different concentrations were studied. The inclusion of sucrose during starch gelatinization resulted in an increase in peak height as the concentration of sugar was increased. Concomitantly, the initial temperature of pasting and peak temperature increased at high sucrose concentrations, while the set-back decreased. Initial temperature of pasting and peak height increased in the presence of sodium chloride up to the 4% level. Beyond this concentration of salt, no distinct peak was obtained. The addition of shortening decreased peak height slightly but increased the set-back. Concentrations of nonfat dry skim milk resulted in higher peak viscosities; however, an irregular type curve was produced. The addition of oxidizing agents such potassium bromate (KBrO3) or potassium iodate (KIO3) at levels commonly used in bread did not affect pasting properties. At high concentrations the peak height increased in the presence of both oxidizing agents. However, with the KBrO3 the set-back was sharply reduced, whereas it was not greatly affected with the KIO3. Ascorbic acid had a similar effect to the KBrO3 on the set-back property. No effect was observed on pasting properties of the starch with low levels of sodium bisulfite, but with higher concentrations the peak height was increased. The effect of the same ingredients on starch pasting properties also was studied utilizing the incorporation of carboxymethyl cellulose. In addition to the amylograph, the temperature of gelatinization of starch in the presence of the baking ingredients was measured by the Kofler miscroscope hot-stage technique, with loss of birefringence used as a criterion of starch gelatinization.