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In the paper, a comprehensive study of rheological properties of 3% (w/v) Japanese kuzu starch pastes was conducted. To describe the experimental data obtained from oscillatory and creep tests, the new rheological model-which was a modification of the fractional Kelvin-Voigt model-was proposed. The model provided an accurate description of the dynamic data in a range of nearly seven logarithmic decades of oscillation frequency v, with an average error equal to 4.7%. It allowed for a precise determination of 17 rheological parameters of the biopolymer in a function of temperature and time of pasting. These parameters have provided a lot of additional information about structure and viscoelastic properties of the test medium in comparison to the classical analysis of dynamic curves G0 and G00 and shear creep compliance J(t). The study indicated that kuzu starch pastes were viscoelastic polydisperse solids. Rising temperature and time of pasting caused an increase in elastic properties and average molecular weight of the biopolymer. The analysis also showed that the specific pasting conditions, 80°C, 15 min; 95°C, 75 min; and 80°C, 30 min, are particularly important from the point of view of structure and rheological properties of products in food, pharmaceutical, and cosmetics industry, respectively. [ABSTRACT FROM AUTHOR]

Large amounts of waste generated by the disposal of non‐biodegradable packaging is a major concern that has stimulated the search for new materials for the development of environmentally friendly packaging. This study aims to produce cassava starch‐based foams incorporated with broken rice, a co‐product of rice milling. Foams were obtained by a thermopressing process, and the influence of broken rice concentration on the formulations is investigated. Broken rice addition is tested for 0 (control sample), 10, 15, 20, and 30% (w/w). Foams containing broken rice show lower thickness and higher density. With respect to water absorption capacity, the control foam and those with 10 and 15% (w/w) of broken rice addition do not present significant statistical differences for any of the tested times. Mechanical properties (tensile strain and maximum flexural stress) are positively influenced by the addition of 10% (w/w) broken rice. Foams made from formulations containing 10% (w/w) broken rice demonstrate higher tensile strain and maximum flexural stress values compared to control foams. Additionally, these foams exhibit a good appearance without superficial cracks. Broken rice is evaluated as an additive in cassava starch‐based foams. Starch‐based foams with broken rice addition (0, 10, 15, 20 and 30%, w/w) are produced by a thermopressing process. Foams containing 10% (w/w) broken rice present higher tensile strain and maximum flexural stress. In addition, these foams are homogeneous, without superficial cracks. [ABSTRACT FROM AUTHOR]