Preparation and characterization of physicochemical properties of glacial acetic acid modified Gadung (Diocorea hispida Dennst) flours

Abstract

In addition to the presence of antinutrients, the inferior physicochemical properties of flours has caused gadung (Dioscorea hispida dennst) becomes one of the underutilized tubers in the world. Acetylation is one of the starch modification methods to alter the physicochemical properties of starch, namely swelling power and solubility. The objective of this work was to investigate the effect of reaction time, glacial acetic acid/flour mass ratio and pH on gadung flour acetylation at ambient temperature. The acetylation was carried out by reacting gadung flour slurry of 20 % consistency with glacial acetic acid under alkaline condition. The results show that in general degree of substitution and swelling power increased with the increase of reaction time, while the solubility was not affected by reaction time after 10 min acetylation. Acetylation led to significant changes in morphology and structure of gadung flour starch granules. Overall, all the acetylated gadung flours obtained in this work were having higher swelling power and solubility than the native flour. Acetylation of gadung flour using glacial acetic acid with 1:3 mass ratio and pH 8.0 at ambient temperature for 30 min resulted gadung flours with swelling power and solubility similar to that of Korean wheat flour.

H2O2/UV Photo-Oxidation of Gadung (Dioscorea Hispida Dennst.) Starch and its Product Physicochemical Characterization

“…They were washed with flowing water to remove dirt, peeled, sliced into chips and detoxified using the method suggested by Kumoro et al with slight modification 22,23 . The reagent-grade 35 % w/w hydrogen peroxide stock solution and other chemicals of analytical grade (purity ≤ 98% w/w) used in this work were purchased from Sigma-Aldrich Pte.…”

Modification of Starches and Flours by Acetylation and Its Dual Modifications: A Review of Impact on Physicochemical Properties and Their Applications

“…Before the reaction, the starch is first conditioned in an alkaline state to form the starch base. An acetate reagent is then added to form starch acetate [ 30 , 65 , 66 , 67 ]. The basic principle of the acetylation reaction by the substitution of starch-free hydroxyl groups with acetyl groups can be seen in Figure 1 .…”

Modified Starch-Based Adhesives: A Review

“…Examples of esterified starch have been reported by many research groups, with variations in ester carbon chain length. Ratnawati et al [ 9 ] utilized glacial acetic acid to modify “Gadung flour” starch, which involved appending acetyl groups onto the saccharide unit in the presence of base catalyst (NaOH). This process afforded a product having a degree of substitution (the moles of substituents per mole of anhydroglucose unit) between 0.16 and 0.20.…”