Properties of extruded whole grain cereals and pseudocereals flours |
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| Authors: | Frédéric Robin Christine Théoduloz Sathaporn Srichuwong |
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| Affiliation: | 1. Nestlé Product Technology Center Orbe, Nestec Ltd, Orbe, Switzerland;2. Department of Food Science and Technology, Nestlé Research Center, Lausanne, Switzerland |
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| Abstract: | Common cereals such as wheat are widely used worldwide in extruded products. Nevertheless, other locally available grains would be beneficial for local consumers regarding taste preference, nutritional needs and sustainability. Locally available cereals, that is millet, teff, sorghum and pseudocereals, that is quinoa and amaranth flours were extruded at the same processing conditions, and the resulting properties were compared to those of extruded refined wheat flour. Amaranth flour contained the highest protein content (16%). Sorghum was the highest in calories because of its high lipid content (10%). The extrusion process greatly increased a water solubility index (WSI) of amaranth from 11% to 61%, while the WSI level of quinoa was almost not affected (WSI of 4%). The expansion properties varied differently among grain types. These grains had a sectional expansion index (SEI) ranging between 11 and 13, which could not achieve the performance of the refined wheat (SEI of 22). The lowest expansion was observed for amaranth flour which contained the lowest starch content. Sorghum extrudates, interestingly, provided comparable stress at rupture value to that of wheat. For the mechanical properties, none of these local grains could fully replace refined wheat at the employed extrusion conditions. |
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| Keywords: | Expansion extrusion fibres starch whole grain |
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