Physico-Chemical Characteristics of Media-Milled Corn Starch

Abstract

Nano/submicrometer scale corn starch particles have been prepared by using media milling. Molecular weight and pasting properties of milled starch were determined by HPSEC-MALLS-RI and an oscillatory rheometer, respectively. After 30-min of milling, the number-average diameter of the starch particle was reduced from 9.61 to 0.26 μm. Particle size was further reduced by extended milling. Microscopic observation confirmed the presence of particles smaller than 100 nm. As starch granules were being disintegrated, the mechanical energy imparted by media milling resulted in 43.7% of starch damage and 55% degree of gelatinization during the initial 30 min. In the meanwhile, the weight average molecular weight was reduced from 9.98 to 7.63 × 10(6) g/mol. The pasting properties were significantly altered by milling, which resulted in lower onset and peak temperature, and reduction in breakdown and set back. The importance of molecular weight on the physicochemical properties of milled starch was discussed.

Material properties of partially pregelatinized cassava starch prepared by mechanical activation

“…Similarly, the peak viscosity and viscosity at different conditions also gradually decreased with increasing the milling time. This may be due to the significant physicochemical property changes of cassava starch under the intensive impact of ball milling, including the breakage of intermolecular and intramolecular hydrogen bonds in main chains of starch, the rupture of starch molecular chains, the destruction of tight starch granule structure, and the decrease of crystalline phase in starch granules [1,27,28]. It shows that the viscosity of cooked PPCS paste decreased as increasing the milling time, but the initial viscosity of PPCS paste in cold water increased with the increase of milling time, which is attributed to the increased degree of gelatinization of PPCS after MA.…”

“…This may be ascribed to high degree of association of native cassava starch molecules caused by the strong tendency for hydrogen bond formation between hydrogen groups on adjacent starch molecules. When suffered from strong mechanical actions during MA, hydrogen bonds on adjacent starch molecules were weakened and the starch molecules were degraded, contributing to a lower setback of PPCS [1]. When used as excipient in pharmacy, the breakdown and setback of PPCS may affect the rigidity and stability of tablets, and the tablets prepared using the PPCS with lower breakdown and setback can have better rigidity and stability.…”

“…When subjected to enough mechanical energy, the chemical bonds in solids can be effectively broken up, along with the collapse of their crystal structure, phase transformation, and the changes in surface characteristics [1,22]. In addition, a part of mechanical energy is converted into thermal energy which can also affect the physicochemical properties of the solids, especially the polymers.…”

“…Starch, a primary carbohydrate polymer, plays an important role in the food industry and it is also used as raw material to prepare different products in other industries [1][2][3]. In pharmaceutical industry, starch and its derivatives are employed as multipurpose excipients in various solid dosage forms, especially as disintegrants, fillers, and lubricants in powder form and as binders in paste form in tablet formulation [4][5][6][7].…”

RESEARCH PAPER Structural changes of corn starch during fuel ethanol production from corn flour

“…However, both the solvent and the solubilization method strongly affect the occurrence of a polysaccharide breakdown. Moreover, the most popular pullulan and dextran molecular weight standards are characterized by slightly different molecular structures and far lower molecular weights when compared to starch, so they can be recommended only for the assessment of the molecular weight of amylose (Lin et al, 2003;Chen et al, 2010;Braun 1993;Jackson, 1991). However, to answer the question regarding the susceptibility of the amylose and amylopectin fractions to amylolysis, knowledge of the absolute values of molecular weight is not essential, in contrast with information on the changes in both molecular weight and percentage of individual fractions.…”