Rheological Behavior of Hot-Air-Puffed Amaranth Seeds

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.

Gluten-Free Breads and Cookies of Raw and Popped Amaranth Flours with Attractive Technological and Nutritional Qualities

“…Raw amaranth dough has higher proportion of elastic component than the viscous one [18]. Therefore, when amaranth is popped, the elastic component increases even more respect to the viscous one [10]. Thus, the rheological properties were improved to reach the best mixing characteristics in the composite 60% popped amaranth: 40% raw amaranth flours.…”

“…Then, water absorption capacity has been attributed to the dispersion of starch in excess of water [11]. This dispersion is enhanced by the degree of starch damage due to gelatinization and fragmentation during processing (e. g. molecular weight reduction of amylose and amylopectin) [10].…”

“…In addition to its ethnic and cereal-like uses, the flour of the raw grain has been used in gluten-free formulations [9] and in other formulations added to wheat for baking because of amaranth proteins improve the rheological behavior of the doughs [5,10]. Furthermore, the popping process of the amaranth grain improves its rheological properties [11] as it happens by extrusion of other grains [12], because the similarity in processing.…”

Optimization of Extrusion Process for Producing High Antioxidant Instant Amaranth (<i>Amaranthus hypochondriacus</i> L.) Flour Using Response Surface Methodology

“…Amaranth does not contain gluten and is therefore a raw material of interest for those suffering from celiac disease [12]. Furthermore, the popping process of the amaranth grain improves its rheological properties [13,14] as it happens by extrusion of other grains [15], because the similarity in processing.…”

Texture Properties of Dutch-Type Cheese as a Function of Its Location and Ripening

“…The relaxation test and, subsequently, Peleg's model have successfully been applied for monitoring of viscoelastic properties of many food matrixes; processed cheese, dough, rainbow trout, cods or hot-air-puffed amaranth seeds might serve as examples. [15,22,[25][26][27][28] The aim of the study was to explore texture properties of individual parts of Dutchtype cheese via hardness and relaxation tests during 126-day ripening.…”