Food Nutrition

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Browsing Food Nutrition by Funder "Alexander Von Humboldt (PRF)"

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    Batter rheology and bread texture of sorghum‐based gluten‐free formulations modified with native or pregelatinised cassava starch and α‐amylase
    (Institute of food Science technology, 2010-05-26) Onyango Calvin; Mutungi Christopher; Ubehend Gunter; Lindhauer Meinolf G.
    Summary The influence of a-amylase (0–0.3 U g)1) on the crumb properties of gluten-free sorghum batter and bread, respectively, was investigated. The formulations were modified using native or pregelatinised cassava starch (i.e. batter A – 17% pregelatinised starch, 83% sorghum, 100% water fwb; batter B – 17% native starch, 83% sorghum, 100% water fwb; and batter C – 30% native starch, 70% sorghum, 80% water fwb). The batters had solid viscoelastic character with the storage modulus predominant over the loss modulus. Storage moduli of batter A decreased with increasing angular frequency, whereas the moduli of batters B and C were independent from the angular frequency. Increasing enzyme concentration did not affect the loss factors of the batters. Batters’ resistance to deformation, from highest to lowest, followed the order C > A > B. Increasing enzyme concentration decreased crumb firmness, cohesiveness, springiness, resilience and chewiness but increased adhesiveness. Overall, breads containing native starch had better crumb properties (i.e. springier and less firm, chewy and adhesive) than breads containing pregelatinised starch.
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    Creep-Recovery Parameters of Gluten-Free Batter and Crumb Properties of Bread Prepared from Pregelatinised Cassava Starch, Sorghum and Selected Proteins
    (International Journal of Food Science & Technology, 2009) Onyango Calvin; Muttungi Christopher; Unbehend Gunter; Lindhauer G. Meinolf
    The effect of egg white, skim milk powder, soy protein isolate and soy protein concentrate on creep-recovery parameters of gluten-free batter made from sorghum and pregelatinised cassava starch was studied. Batter treated with egg white had the highest deformation and compliance parameters and lowest zero shear viscosities and differed significantly (P < 0.05) from the other treatments. However, this batter recovered its elasticity sufficiently and its elastic portion of maximum creep compliance did not differ significantly (P < 0.05) from the other treatments. Unlike the other treatments, egg white did not decrease bread volume and exhibited the lowest crumb firmness and staling rate. Optimisation of the amount of egg white with diacetyl tartaric acid esters of mono and diglycerides (DATEM) showed that creep-recovery parameters and crumb hardness were affected by the linear, quadratic and interaction effects of the input variables. Treatment with 6% and 0.1% w ⁄ w fwb egg white and DATEM, respectively, gave gluten-free batter with the least elastic portion of maximum creep compliance (Je ⁄ Jmax = 11.65%) which corresponded to the lowest crumb firmness (790.8 g).
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    Effect Of Cellulose-Derivatives and Emulsifiers on Creep-Recovery and Crumb Properties of Gluten-Free Bread Prepared from Sorghum and Gelatinised Cassava Starch
    (Food Research International, 2009) Onyango Calvin; Ubehend Gunter; Lindhauer G. Meinolf
    The effect of cellulose-derivatives and emulsifiers on the creep-recovery behaviour of glutenfree dough prepared from gelatinised cassava starch and sorghum was studied. Cellulose treated doughs, except the treatment with 2.4% w/w fwb CMC, had lower resistances to deformation (range 10–33%) than emulsifier-treated doughs (range 3–13%). The higher elastic recovery of emulsifier-treated doughs corresponded to lower compliances and higher zero shear viscosities than for doughs treated with cellulose-derivatives. Addition of egg white powder (6.7% w/w fwb) eliminated several textural defects associated with gluten-free bread. Cellulose-derivatives did not decrease crumb firmness or staling rate when compared to the control. Though increasing emulsifier concentration (from 0.4% to 2.4% w/w fwb) decreased crumb firmness, crumbs treated with 2.4% w/w fwb emulsifiers, except diacetyl tartaric acid esters of mono- and diglycerides, were weak and difficult to handle after slicing. Nevertheless, all gluten-free breads treated with 2.4% w/w fwb emulsifiers staled at a slower rate than the control.