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- Bernin, Diana, 1979, et al.
(författare)
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Multi-scale characterization of pasta during cooking using microscopy and real-time magnetic resonance imaging
- 2014
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 66, s. 132-139
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Tidskriftsartikel (refereegranskat)abstract
- Macroscopic properties of pasta, such as the texture, are formed during cooking by a complex interplay of water and heat with the structuring agents starch and gluten. The impact of the starch-to-gluten ratio on microstructure and water distribution in pasta was analyzed by a multi-scale approach combining magnetic resonance imaging (MRI) and light microscopy. The cooking process and thus the water distribution was monitored non-invasively using 1H MRI in real-time with a temporal resolution of 45s. Our MRI set-up allowed following the water ingress by imaging the reduction of the uncooked core. The water ingress rate was neither dependent on pasta composition nor on the presence of salt in the cooking media (0.7% NaCl). Starch-rich samples showed a more homogeneous water distribution in the gelatinized zone, which was mirrored in a more homogeneous microstructure. In contrast, gluten-rich samples showed both a heterogeneous water distribution and microstructure. Thus, the gluten content affected local water content in the gelatinized zone but not the water ingress. © 2014 Elsevier Ltd.
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| 2. |
- Steglich, Thomas, 1983, et al.
(författare)
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Bran particle size influence on pasta microstructure, water distribution and sensory properties
- 2015
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Ingår i: Cereal Chemistry. - 0009-0352 .- 1943-3638. ; 92:6, s. 617-623
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Tidskriftsartikel (refereegranskat)abstract
- Whole-wheat pasta offers improved nutritional value compared to regular pasta, but lacks appeal to many consumers due to its negative organoleptic properties, such as texture and taste. Various approaches have been studied to improve these properties in whole-wheat products. Optimizing bran particle size showed its potential in noodles, but studies of its effects in pasta are scarce. Therefore, we produced spaghetti enriched with bran fractions similar in chemical composition, but with varying median particle sizes of 90, 160, 370 and 440 µm. The effect of bran particles and their median size on dried and cooked pasta was studied by light microscopy and 3D 1H magnetic resonance imaging. In general, bran particle size did not influence the macrostructure in cooked spaghetti. However larger bran particles created a more heterogeneous microstructure in contrast to smaller particles and affected starch granule swelling. Sensory analysis indicated a preference for pasta containing smaller particles. Our results give new insight into the microstructural features responsible for the negative consumer appeal, and could be used to guide future efforts in designing improved pasta formulations.
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| 3. |
- Steglich, Thomas, 1983, et al.
(författare)
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Microstructure and water distribution of commercial pasta studied by microscopy and 3D magnetic resonance imaging
- 2014
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 62, s. 644-652
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturing pasta is a rather well known process, but it is still challenging to tailor pasta products with new raw materials. In this study, we evaluated the effects of raw materials on the microstructure and water distribution in cooked pasta using H-1 magnetic resonance imaging (MRI) as well as bright field and polarized light microscopy. The MRI parameters initial intensity (I-0) and transverse dephasing time (T-2*) serve as indicators of the local water concentration and water-macromolecule interactions through chemical exchange, respectively. These parameters were mapped throughout the whole pasta volume with a spatial resolution of 78 mu m in all three dimensions. MRI was combined with light microscopy to link I-0 and T-2* to microstructure components such as fiber particles and the extent of starch gelatinization. Four commercial spaghetti samples were analyzed which were made of durum wheat flour, both plain and enriched with wheat fiber, as well as with wholegrain and soft wheat flour. Although all pasta samples showed similar macroscopic water absorption as measured by weight increase, the sample structures differed at the microscopic scale. Compared to durum wheat spaghetti, the presence of fiber particles decreased T-2*, while spaghetti enriched with soft wheat flour increased T-2*. In addition, light microscopy showed that large fiber particles partly acted as barriers against water migration and protected starch granules from swelling. Smaller wheat fiber particles did not affect local starch swelling. Thus, the combination of light microscopy and MRI is a powerful tool to study the microstructure and water distribution in pasta.
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