  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
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Use of Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) to study doughs and starches as they are heated. O. Sevenou, S. E. HILL, I. A. Farhat, and J. R. Mitchell. Division of Food Sciences, University of Nottingham, Sutton Bonington Campus, Loughborough, Leics, LE12 5RD, UK.
On heating cereal products changes occur to the protein, starch and water levels. Many methods are available that give information about these changes, but samples are typically heated and then allowed to cool before assessment. Thus the results may not indicate the true situation occurring during the heating process. Starches and doughs have been heated in-situ and assessed using ATR-FTIR. The order within starch granules was followed at two wavenumbers (1047 and 1022 cm(^-1)). During heating there was a loss of order in the starches and the loss of short-range order as detected by FTIR was closely correlated to Differential Scanning Calorimetry (DSC) endotherms when the same heating rates were used. This was the case for wheat, waxy maize, maize, potato and pea starches. The amide-2 region of the spectra is sensitive to the hydration of the gluten and variation in the ratio 1545/1512 cm(^-1) indicates water movement. As temperature is increased the ratio 1545/1512 cm(^-1) decreased. The ratio 1545/1512 cm(^-1) measured at room temperature as well as its variation as a function of temperature were affected by the addition of starch to the gluten. This showed that the starch fraction does not only work as filler in dough but has an effect on the gluten fraction's properties during the whole baking process. The use of ATR-FTIR would therefore seem to be a useful tool for the understanding of the interactions occurring in complex cereal products as they are heated.
Copyright 2001
The American Association of Cereal Chemists