No abstract

Force-deformation and force-relaxation experiments were performed on amaranth seeds puffed at 290, 330 and 370°C. Less force and energy was required to cause a given deformation in seeds processed at 290°C than in those puffed at 330 and 370°C. It was also observed that the forces and energies required to produce a given deformation did not differ significantly (p £ 0.05) for seeds puffed at 330 and 370°C. The three-element generalized Maxwell model and Peleg model were applied for modeling force relaxation of puffed amaranth seeds. It was found that the generalized Maxwell model predicted the experimental data better than the Peleg model. The elastic parameters and asymptotic residual force of the generalized Maxwell model were significantly affected by puffing temperature, showing an increase with its rise. Relaxation times were not significantly affected by the puffing temperature. It was concluded that a higher puffing temperature resulted in a more rigid material and less viscous behavior.

Grit made of crude and expanded amaranth seeds was added to meat-fat batter in order to determine its effect on its quality. Amaranthus cruentus seeds were expanded by the nonpressure method and graded by density (degree of expansion) into three fractions: 341, 208 and 135 kg/m3; crude seed density was 800 kg/m3. Then the seeds were ground to a homogeneous mass with granulation of 0.8 mm. The water-holding capacity and viscosity of grit made of crude and expanded seeds were determined. Class II pork was used for the production of meat-fat batter. Cooking losses were determined in model meat-fat batter, pasteurized and sterilized cans. The texture and color parameters of canned meat were also determined, and a taste-panel evaluation was made. It was found that expanded seed grit was characterized by worse hydration and gelling properties than crude seed grit. Grit made of crude amaranth seeds had a positive effect on the water-holding capacity of stuffing and allowed to reduce the cooking losses in cans. Better water-holding capacity resulted in an improvement in the tenderness, juiciness and taste of canned meat. Its quality deteriorated when large amounts of highly-expanded seed grit were used.