Physicochemical properties of expanded extrudates from colored sorghum genotypes

Abstract

The diversity of sorghum grains is related to their intrinsic properties, which include starch type, non-starch components and phenolic compounds. The latter are genotype dependent and affect the pericarp characteristics such as color and presence of a pigmented testa. This diversity can be valuable for developing new food products by thermoplastic extrusion intended for human consumption. Flours from sorghum grains from the genotypes of varied pericarp color: white (CMSXS180; 9010032), red (BRS 310; BRS 308) and light brown (BRS 305; 9929034) were processed in a co-rotating twin-screw extruder. Changes promoted by extrusion cooking were evaluated via specific mechanical energy (SME), die pressure, apparent density, sectional expansion index (SEI), water absorption index (WAI) and water solubility index (WSI). Pericarp color affected die pressure, apparent density and WSI values of extrudates. Light brown genotypes, rich in tannin and fiber content, generated the lowest die pressure and SEI values. Red genotypes presented the lowest SME and the highest WAI values. White genotypes presented intermediate SME and the highest die pressure values. These results reflect differences in starch conversion induced by the pericarp type. These results further suggest the potential use of pigmented sorghum extrudates for human consumption.

Composition, in vitro digestibility, and sensory evaluation of extruded whole grain sorghum breakfast cereals

“…Vargas-Sol orzano et al (2014) reported a slight, and in some cases non-significant, increase in WAI in red sorghum extrudates compared with white. The lack of a difference in the present study may be due to different genotypes used or different processing conditions.…”

“…The cereals produced from tannin-containing sorghum possessed high antioxidant activity. Vargas-Sol orzano, Carvalho, Takeiti, Ascheri, and Queiroz (2014) reported that pericarp color (white, red, and brown) affect the die pressure during extrusion, as well as sectional expansion index and water absorption index (WAI) of the extrudates.…”

Cereal processing and glycaemic response

“…Some studies (Altan et al, 2009;Mahasukhonthachat et al, 2010b;Vargas-Sol orzano et al, 2014) stated the feed rates as the sum of the flow rates of water and dry components with feed moisture contents. Some studies (Altan et al, 2009;Mahasukhonthachat et al, 2010b;Vargas-Sol orzano et al, 2014) stated the feed rates as the sum of the flow rates of water and dry components with feed moisture contents.…”

“…Extrudates from high-amylose varieties generally have more RS and less RDS than their waxy relatives. Extrusion cooking is a highly researched area, and various studies examined how extrusion conditions and feed properties affected extrudate characteristics (Vargas-Sol orzano et al, 2014;Singh et al, 2016). cross-linking) that reduce starch digestibility (Brennan et al, 2013) and glycaemic responses, to the extent depending on extrusion conditions.…”

Use of Red Cactus Pear (Opuntia ficus-indica) Encapsulated Powder to Pigment Extruded Cereal

“…Encapsulated powder in the mixture favors the presence of sugars, fibers, and other compounds such as pigments that replace starch [33], preventing expansion and increasing cereal density. In addition, the presence of compounds such as polyphenols, or compounds with hydroxyl groups (betalains) that can form a complex with starch [34], helps compact the cereal matrix to increase Journal of Food Quality 5 the efficiency of molecular packing [35]. Similar results were obtained by Altan et al [15], who reported that increases in tomato pulp levels caused an increase in extrudate bulk density, and by Khanal et al [14].…”