Physicochemical Properties of Flours that Relate to Sorghum Couscous Quality

Abstract

Cereal Chem. 76(2):308-313Flours from eight sorghum cultivars were evaluated for their couscousmaking ability with the objective of finding predictive relationships between flour physicochemical properties and couscous quality. Chemical composition, physical characteristics, and pasting and gelatinization properties of the flours were determined. A laboratory procedure was used to prepare couscous. Couscous properties were evaluated and compared to a laboratoryprepared and a commercial durum wheat couscous. Hard grain produced flours containing a high proportion of coarse particles with low ash and high damaged starch content and yielded a higher proportion of desirable sorghum couscous granules. A variety of colors ranging from brown to yellow were obtained when flours were processed into couscous. Cooked sorghum couscous stickiness was positively correlated (r = 0.89, P < 0.01) with the amount of damaged starch in flour. Cooked couscous hardness correlated positively (r = 0.79, P < 0.05) with apparent amylose content of flour and correlated negatively (r = -0.75, P < 0.05) with flour peak viscosity. Durum wheat couscous was lighter and had more yellow color than sorghum couscous. Sorghum couscous was stickier and harder than durum wheat couscous. Addition of 2% oil to the cooking water considerably improved the texture of some sorghum couscous to a level comparable to that of durum wheat couscous.

Relationship of Sorghum kernel size to physiochemical, milling, pasting, and cooking properties

“…Pasting properties of sorghum flour are a key to understanding the physical characteristics and potential utilization. Aboubacar and Hamaker (1999), and Akingbala and Rooney (1987) reported differences among sorghum cultivars and an apparent association of amylose con- tent with peak viscosity using a Brabender Visco-Amylograph. Our results confirmed differences due to seedlot (Table 1), but because of significant kernel sizeÂseedlot interactions, gave no consistent evidence that particular RVA pasting properties can be attributed to kernel size.…”

“…In sorghum, grain hardness is the most important and consistent characteristic that affects porridges (Rooney, Kirleis, & Murty, 1986). Aboubacar and Hamaker (1999) reported that hard sorghum grain produced flours containing a high proportion of coarse particles with low ash and high damaged starch content and yielded a higher proportion of desirable sorghum couscous granules.…”

Sustainable Agriculture Reviews

“…White colored grain sorghum varieties from tan type plants yielded the best couscous product (Galiba et al 1988 ). Couscous quality depends upon the size uniformity, color, stickiness and mouth-feel of the product (Aboubacar and Hamaker 1999 ).…”

Sorting of Fungal-damaged White Sorghum

“…Grain hardness in sorghum has been related to quality in several food products. Grain hardness has been found to influence the cooking quality of pearled sorghum (Cagampang and Kirleis 1984), sorghum porridge (Rooney et al, 1986), couscous quality (Aboubacar and Hamaker 1999) and sorghum bread quality (Schober et al, 2005). Grain hardness has also been reported to play a role in the milling quality of sorghum (Maxson et al, 1971, Munck et al, 1981, Munck 1995, Rooney and Waniska 2000 and is related to mold susceptibility and resistance in sorghum breeding lines (Jambunathan et al, 1992;Menkir et al, 1996b).…”