Food Processing

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Browsing Food Processing by Author "Christopher Mutungi"

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    Debranched Cassava Starch Crystallinity Determination by Raman Spectroscopy: Correlation of Features in Raman Spectra with X-Ray Diffraction And 13C CP/MAS NMR Spectroscopy
    (Carbohydrate Polymers, 2012-01-04) Christopher Mutungi; Lars Passauer; Calvin Onyango; Doris Jaros; Harald Rohm
    Because starch crystallinity influences the physical, mechanical, and technological aspects of numerous starch-based products during production and storage, rapid techniques for its assessment are vital. Samples of different levels of crystallinity were obtained by debranching gelatinized cassava starch, followed by subjection to various hydrothermal treatments. The recrystallized products were further subjected to partial hydrolysis with a mixture of α-amylase and glucoamylase prior to freeze–drying. Crystallinities were determined using X-ray diffraction (XRD) and 13C CP/MAS NMR spectroscopy, and correlated with FT-Raman spectra features. XRD crystallinities ranged between 0 and 58%, and agreed with crystalline-phase fractions (R2 = 0.99) derived from the respective 13C CP/MAS NMR spectra. A strong linear correlation was found between crystallinities and integrated areas of the skeletal mode Raman band at 480 cm−1 (R2 = 0.99). With appropriate calibration, FT-Raman spectroscopy is a promising tool for rapid determination of starch crystallinity.
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    Modification Of Gluten-Free Sorghum Batter and Bread Using Maize, Potato, Cassava or Rice Starch
    (LWT - Food Science and Technology, 2011-04) Calvin Onyango; Christopher Mutungi; Günter Unbehend; Meinolf G. Lindhauer
    Gluten-free sorghum bread was made from cassava, maize, potato or rice starch and sorghum in the ratios 10:90, 20:80, 30:70, 40:60 and 50:50. The other baking ingredients, on flour-weight-basis, were water (100%), sugar (6.7%), egg white powder (6%), fat (2%), salt (1.7%) and yeast (1.5%). Increasing starch content changed the batters’ consistencies from soft doughs to thin pourable batters. Increasing starch content decreased crumb firmness and chewiness, and increased cohesiveness, springiness and resilience of all breads. Cassava-sorghum and rice-sorghum breads had better crumb properties than maize-sorghum or potato-sorghum breads. Although the crumb properties of all breads declined (i.e. firmness and chewiness increased; cohesiveness, resilience and springiness decreased) on storage, the formulation containing 50% cassava starch retained the best overall texture.