Published Date
Received 25 August 2008, Revised 21 November 2008, Accepted 23 December 2008, Available online 14 January 2009.
Author
Abstract
The aim of this work was to identify the transitions in the complex DSC profiles of potato starch at a low water content. Preparative DSC involves the thermal processing of samples in stainless steel DSC pans in a way that allows their subsequent structural characterization. The low temperature (LT), dual melting (M1–M2), and high temperature (HT) endotherms observed in DSC profiles of potato starch with 16% water were assigned to enthalpy relaxation, melting with preservation of granular identity, and transition of the melted granules into a molecular melt, respectively. Granular melting was accompanied by a strong reduction of swelling capacity. Significant molecular degradation was observed after the HT transition. There is evidence that HT does not represent a true thermodynamic transition, but is due to a volume change in the sample. In contrast to potato starch, maize starch with 16% water gave inhomogeneous samples after processing, presumably because of its low packing density.
For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0144861709000277
Received 25 August 2008, Revised 21 November 2008, Accepted 23 December 2008, Available online 14 January 2009.
Author
- TNO Quality of Life, Food and Biotechnology Innovations, PO Box 360, 3700 AJ Zeist, Netherlands
Abstract
The aim of this work was to identify the transitions in the complex DSC profiles of potato starch at a low water content. Preparative DSC involves the thermal processing of samples in stainless steel DSC pans in a way that allows their subsequent structural characterization. The low temperature (LT), dual melting (M1–M2), and high temperature (HT) endotherms observed in DSC profiles of potato starch with 16% water were assigned to enthalpy relaxation, melting with preservation of granular identity, and transition of the melted granules into a molecular melt, respectively. Granular melting was accompanied by a strong reduction of swelling capacity. Significant molecular degradation was observed after the HT transition. There is evidence that HT does not represent a true thermodynamic transition, but is due to a volume change in the sample. In contrast to potato starch, maize starch with 16% water gave inhomogeneous samples after processing, presumably because of its low packing density.
For further details log on website :
http://www.sciencedirect.com/science/article/pii/S0144861709000277
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