Cereal Chem 57:262 - 266. | VIEW
Chlorinated and Heat-Treated Flours: Studies of the Dynamics of Starch Gelatinization by Small-Angle Light Scattering.
Z. H. Bhuiyan and J. M. V. Blanshard. Copyright 1980 by the American Association of Cereal Chemists, Inc.
Chlorinated and heat-treated flours and their controls were dispersed in water at a concentration of 15% (w/w) and subjected to temperature jumps of approximately 2 and approximately 4 C. Their reactions were examined by the technique of small-angle light scattering. The time response of the birefringence loss was interpreted as a two-component exponential, and the variation with progressive gelatinization of both the fractional amplitude of the slow component (B/[A+B]) and the response time of the slow component tauB was studied in detail. The numerically summed response curves of the slow components of the treated flours were significantly different from those of the control flours. The reproducibility of the technique appeared satisfactory. When the results were normalized and those of the respective controls were subtracted from those of the treated flours, a distinct difference in time response was observed. With approximately 2 C jumps, the maximum difference was at about 500 sec for both treated flours, whereas with approximately 4 C jumps, the maximum difference was at 150 sec for the heat-treated and 100 sec for the chlorinated flours. A summed response time index, [equation], clearly distinguished the treated and control flours. The differences were interpreted in terms of the semicooperative hypothesis of gelatinization, which gave evidence that the treated flours swell to a greater extent.