Search

This study evaluated the physical properties of cassava foam powder (CFP) produced from white and yellow cassava by foam mat drying, and compared them with cassava pulp powder (CPP). Cassava foams were prepared, dried and milled to foam powder. The white CFP and yellow CFP had a true density of 1.466 g/cm3 and 1.534 g/cm3, respectively. The flow properties determined include Carr's index (CI), angle of repose (θ) and coefficient of static friction (μ s). Micrographs of the CFP revealed that the foam powders were irregular, coalesced, and larger in size than CPP. The rehydration kinetics showed an estimated equilibrium water gain (WG eq) of 0.725–1.680 g/g at temperatures between 30 °C and 70 °C. Adsorption isotherm of the powders was best fit by the Halsey model. There were significant correlations between packed density and angle of repose (r = 0.972), CI (r = 0.970) and mean particle size (r = −0.957). [Display omitted] • Flow properties of cassava were significantly improved by foam mat drying. • Foam mat drying reduced the density and increased the rehydration capacity of cassava. • Microstructure of cassava powders showed non-normal distribution of particle size. • Significant correlations exist between the packed density and angle of repose of cassava powders. [ABSTRACT FROM AUTHOR]

Cassava foam, another form in which cassava may potentially be used as food, was produced from the pulp of yellow-flesh and white-flesh cassava varieties by whipping with foaming agent (20 %w/w glycerol monostearate colloid, GMS) and stabilizer (sodium carboxymethyl cellulose, NaCMC). Cassava foaming was optimized for concentration of foaming agent, stabilizer and whipping time. Using Box-Behnken experimental design, two responses were measured: foam expansion (FE, %) and foam density (FD, g/mL). White-flesh cassava pulp required 14.97% GMS, 0.51% NaCMC and 2.07 min to give a foam of 52.63% expansion and density of 0.75 g/mL. Yellow-flesh cassava pulp required 14.29% GMS, 0.6% NaCMC and 2 min to yield a foam of 48.25% expansion and density of 0.76 g/mL. Predicted optimal FE and FD were 54.9% and 0.73 g/mL for white-flesh cassava foam, and 49.86% and 0.73 g/mL for yellow-flesh cassava foam, respectively, and are close to validated values. The optimal foams were quite stable after 4 h at 25 ± 2 °C, with low volume collapse of 1.79% and 1.26% for white and yellow cassava foams, respectively. The optimal cassava foams were dried into foam powder. There was significant difference in color values (L*, a*, b*, C*, E*, H*, % W, Δ E y e l l o w − w h i t e ∗ ) and total carotenoids content of pulp, optimal foam, and powder of both varieties. Microstructure analysis of the optimal foams revealed round air bubbles and positive skewed distribution of bubble sizes. Foaming and drying significantly reduced total cyanogenic potential in cassava, and may be considered as processing operations capable of reducing cyanogenic potential in cassava considerably. Image 1 • Process variables for foaming of cassava were optimized and experimentally validated. • A comparison of the properties of cassava pulp, foam and foam powder were evaluated. • The cyanogenic potential of cassava was significantly reduced by foaming and drying. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate quality and shelf life of beef meat cooked under sous vide conditions then extended refrigerated storage for 10 weeks. Biceps femoris (n = 6) from six to seven year old cows were treated with 2 g/L ginger powder (GP) containing zingibain or control (no injection) and were then cooked in sous vide conditions at 65 °C for 1 h or 8 h. Cooked samples were evaluated for physicochemical (pH, total water content, cooking loss, Warner-Bratzler shear force (WBSF), texture profile analysis (TPA), L *, a* , b * properties and thiobarbituric acid reactive substance (TBARS)), microstructure (scanning electron microscopy) and microbiological (Brochothrix thermospacta, Clostridium perfringens , Lactic acid bacteria, Listeria monocytogenes, Salmonella spp , and yeasts and moulds) quality after vacuum packing, cooking, then refrigerated storage at 4 °C for 0, 2, 4, 8 or 10 weeks. Physicochemical parameters were improved by GP treatment (P < 0.05) while there was no effect of storage time on WBSF, TPA or microstructure. The microbial quality of sous vide cooked meat in refrigerated storage appeared to be four weeks and oxidation shelf life of the cooked meat was found to be two weeks under refrigerated storage. [ABSTRACT FROM AUTHOR]