Seed treatments affect functional and antinutritional properties of amaranth flours

Abstract

The effects of seed treatments, including cooking, popping germination and flour air classification, on the functional properties and antinutritional factors of Amaranthus caudatus and Amaranthus cruentus seeds were studied. Thermal treatments increased the water absorption with a maximum value of 5.1 and 6.3 g g −1 in flour of popped seeds of both species. Generally, fat absorption increased after the treatments. Air classification and germination followed by drying at low temperature increased the foam stability of the flours, while thermal treatment and germination followed by drying at higher temperatures reduced the foam stability. All treatments except air classification decreased the emulsion stability. Also, all treatments except germination followed by drying at 30 • C increased the flour dispersibility, whereas the soluble nitrogen index was increased in the germinated seed flours and decreased in thermal treated seeds and air-classified flours. Air classification increased the contents of phenolic compounds and phytate and decreased the contents of enzyme inhibitors, whereas the thermal treatments reduced the contents of phenolic compounds, phytate and enzyme inhibitors to a greater extent for cooking than for popping. Germination followed by drying reduced the level of phenolic compounds, phytate and enzyme inhibitors.

Antioxidant capacity of amaranth products: effects of thermal and enzymatic treatments

“…The total phenolic content in the flours (WAF and DAF) and APC was 0.4 to 5.6 mg GAE/g sample and within the range of values reported for amaranth in the literature, which varied from 0.15 to 5.24 mg GAE/g sample (GORINSTEIN et al, 2007;GAMEL et al, 2006). The protein concentration processing to obtain the APC resulted in phenolic concentration almost four times higher while it was reported that the most common methods for processing amaranth grains-cooking, popping, and extrusion -reduced the mean total phenolics content in amaranth grain (QUEIROZ et al, 2009).…”

“…As found by Gamel et al (2006) and Queiroz et al (2009), flours from cooked and popped amaranth seeds presented lower phenolic contents than untreated amaranth seeds, while other studies showed an increase of total phenolic content in heattreated samples (GAHLER; OTTO;BÖHM, 2003;JEONG et al, 2004).…”

“…The total phenolics content was determined in the aqueous and methanolic extracts using Folin-Ciocalteau reagent (FCR; Sigma Chemical Co, St. Louis, MO, EUA), according to Gamel et al (2006). Gallic acid (3,4,5-trihydroxybenzoic acid, Sigma Chemical Co, St. Louis, MO, USA) in distilled water (0.02 to 0.12 mg mL -1 ) was used as standard for calibration curve and the results were expressed in gallic acid equivalents (mg GAE/g dry sample).…”

Characterization and nutritional value of precooked products of kiwicha grains (Amaranthus caudatus)

“…Amaranth is a pseudocereal which is believed to have originated in central and southern America (Gamel et al, 2006). The genus Amaranthus contains over 60 species and most of them are native to Latin America (Schoenlechner et al, 2008).…”

Analysis of the Genetic Diversity and Population Structure of Amaranth Accessions from South America Using 14 SSR Markers

“…The amaranth grain is a valuable food as it has a high protein content and well-balanced amino acid profile (Gamel et al, 2006). Analyses of the chemical composition and nutritional value of amaranth grain (Bressani et al, 1987;Dodok et al, 1997;Andrasofszky et al, 1998) confirmed its potential for use in human and animal nutrition as well as medicine (Oke, 1983;Teutenico and Knorr, 1985).…”