Physicochemical properties of cassava starch oxidized by sodium hypochlorite

Abstract

In this work, cassava starch was modified by treatment with sodium hypochlorite (NaClO) at different concentrations (0.8, 2.0 and 5.0 % of active chlorine) and selected physicochemical properties of the oxidized starches were investigated. The native and modified samples were evaluated considering moisture, carboxyl content, apparent viscosity, susceptibility to syneresis, mid-infrared spectroscopy and crystallinity index. The treatment with NaClO resulted in alterations in carboxyl content of the oxidized starches that increased with increasing concentration of the oxidant. Oxidized starches also showed higher susceptibility to syneresis, as assessed by the release of liquid during freezing and thawing. Apparent viscosity analysis showed decrease in peak viscosity of the oxidized starches. X-ray diffractograms showed that the oxidation influenced the extent of cassava starch relative crystallinity found to lie between 34.4 % (native) and 39.9 % (2.0 % active chlorine). The infrared spectra are sensitive to structural changes on starch macromolecules and presented characteristic peaks as C-O-C of the six carbon glucose ring absorbs at 1,150-1,085 cm −1 and due to axial deformation these bands changed with the crystal structure of the starch samples.

Investigation of the photo-oxidation of cassava starch granules

“…The singular technological properties of cassava starch, such as the non-existence of the typical ''cereal flavour'' as found in corn and other cereal starches, as well as its capability for higher swelling during cooking and lower pasting temperatures, allow cassava starch to be used in several industrial applications [6].…”

“…Starches can be modified by chemical, physical, enzymatic or combined methods. Oxidative modification has been the subject of much research, mainly on how to develop starch pastes with more fluidity, cohesion, transparency and whiter granules [5,6,10,11].…”

Study of the Effects of Ultraviolet Light and Sodium Hypochlorite Solutions on Properties of Cassava Starch Granules

“…Among these properties are the nonexistence of the typical Bcereal flavour^of corn and other cereal starches, its capacity for a higher degree of swelling during cooking, and lower pasting temperature. Its low protein and lipid contents must also be considered, which contribute to its neutral flavour and white colour [2].…”

“…Starches can be modified by chemical, physical, enzymatic or combined methods. Oxidative modification has been subject of much research; it is mainly used to produce starch pastes with more fluidity and cohesion and whiter granules, as well as more transparent pastes [2,7].…”

Thermoanalytical Study on the Action of Nitric Acid Up Cassava Starch Granules

“…In its native form, starch has some technological constraints that need to be improved in order to make it possible and use it in industrial applications. Starches in the native form have some limitations in its applications thus the modified starches are largely used in several industries due to their different functionalities and new desirable properties [1][2][3][4][5][6].…”