Comparison of Functional Properties between Native and Chemically Modified Starches from Acha (<i>Digitaria</i> Stapf) Grains

Abstract

Acha grain (Digitariaexilis) starch was isolated and subjected to chemical modifications by acetylation, benzylation, succinylation, carboxymethylation and acid-thining. Functional properties (swelling, solubility, gelation, oil and water absorption capacities, alkaline water retention) and rheological properties of the native and modified starches were determined. Swelling power and solubility of the starch samples increased with increase in temperature. Swelling power and solubility were pH dependent, with maximum values obtained at pH 12 in both native and modified starches. Increasing degree of alkalinity increased both solubility and swelling capacity. Water absorption capacities of chemically modified starches decreased, but acetylated starch, ATAS showed higher value compared to the native and also chemically modified starches improved oil absorption capacity of the native starch. The modified starches showed increase in alkaline water retention. Gelation studies revealed that ACAS had higher LGC than the native while some chemically modified starches did not alter the gelation capacity of the native starch except for BAS and ACAS with LGC of 10% and 16% v/w. There were significant differences in functional properties between native and chemically modified starches from acha, so chemical modification improved functional properties. Chemical modifications increased pasting temperature except for ATAS and BAS. Set-back values were reduced after modifications, indicating that modification would minimize starch retrogradation.

Effect of varying degrees of succinylation on the functional and morphological properties of starch from acha (Digitaria exilis Kippis Stapf)

“…Emeje et al, 2012 observed that Acetylated acha starch had better functional properties than the Native starch. Olu-Owolabi, Olayinka, Adegbemile, and Adebowale (2014) endeavored to compare the functional properties of Native acha starch with its chemically modified forms. He concluded amongst other findings that chemical modification increased pasting temperature and reduced setback values.…”

Effect of thermal pretreatments on physical, phytochemical, and antioxidant properties of black rice pasta

“…An increase in pasting temperature elucidated that the pretreatment of black rice pasta increases the crystalline region due to the reorientation of starch granules. As the crystallinity increases the potency of bonding between the molecules which makes more heat involvement in paste formation (Olu‐Owolabi, Olayinka, Adegbemile, & Adebowale, ). The peak, hold, and final viscosity of untreated pasta were 2,452, 1,635, and 2,979 cP, respectively.…”

Modification of amaranth (Amaranthus viridis) starch, identification of functional groups, and its potentials as fat replacer

“…The esterification process was carried out as described by Lawal () and Olu‐Owolabi, Olayinka, Adegbemile, and Adebowale () with some modifications. The native starch (150 g) was suspended in 500 mL of distilled water and magnetically stirred for 20 min.…”