Compressive Stress-Strain Relationships of Two Puffed Cereals in Bulk |
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Authors: | CHRISTOPH NUEBEL MICHA PELEG |
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Affiliation: | Authors Nuebel and Peleg are with the Dept. of Food Science, Univ. of Massachusetts, Amherst, MA 01003. |
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Abstract: | The compressive stress-strain relationships of two puffed cereals, rice and corn based, in bulk were determined using a Universal Testing Machine. The general sigmoid shape of the relationship could be described by a four parameter empirical model originally developed for cellular solids. Jaggedness could be expressed in terms of an apparent fractal dimension and/or the mean magnitude of the power spectrum determined using the Fast Fourier Transform. Both measures as well as a particular parameter of the empirical model were sensitive indicators of the changes in the stress-strain relationships resulting from exposure to different relative humidities. Although the stress strain relationship, especially of dry samples, had an irregular, irreprodu-cible shape, the magnitude of the two roughness measures was highly reproducible. |
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Keywords: | cereal rice corn fractals water activity |
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