Effect of enriching potato and corn starch with iron ions on selected functional properties

Abstract

This study was aimed at establishing the effect of saturating starches from different botanical origins with iron ions on selected physicochemical properties of the resulting modified starch. Native and modified starches were determined for amylose, protein, fat, and phosphorus content as well as water binding capacity and solubility in water. In addition, the number of iron ions was assayed by atomic absorption spectroscopy (AAS). The thermal properties of samples were also examined using a differential scanning calorimeter (DSC). Flow curves were plotted and described using the Ostwald de Waele model, and the degree of paste structure recovery was determined. Samples enriched with iron ions were treated thermally and radical generation in the starch structure was assayed by means of electron paramagnetic resonance (EPR). AAS analysis proved the presence of iron ions in the investigated modified starch preparations. The results achieved established that enriching starch with iron ions affected the rheological and thermal properties of starch preparations. However, the extent and nature of these changes depended on the botanical origin of the starch. This was also a factor in the thermal generation of radicals, a process, which appeared to be more effective in potato starch preparations.

Effect of Phosphorylation and Copper(II) or Iron(II) Ions Enrichment on Some Physicochemical Properties of Spelt Starch

“…Magnesium, although being the least abundant of the minerals present in the starch and monostarch phosphate examined in this investigation, was the most resistant to leaching. Similar results have been observed in the saturation of potato and corn starches (Rożnowski et al 2014). The fact that the leaching rate of calcium and magnesium from the starch and monostarch phosphate was lower than that of potassium demonstrates that bivalent ions are much more strongly bound by such features as "calcium bridges" (Pałasiński, 1968), which resist leaching much more effectively than univalent ions.…”

“…The presence of iron(II) ions led to a decrease in shear stress over the entire range of measurement, while copper(II) ions did not affect the shear stress compared with the pure monostarch phosphates. Similar correlations have been reported with respect to natural potato and corn starches enriched with iron (Rożnowski et al 2014); for any given shear rate, enriched pastes had much lower shear stress than natural starch pastes. Neither phosphorylation nor mineral enrichment affected the flow index (n) ( Table 4).…”

“…Rożnowski et al (2014) also reported leached phosphorus from potato starch granules during modification with FeSO4, whereas phosphorus content in corn starch after rinsing with ions solutions showed no statistically significant changes relative to control corn starch. The phosphorus present in starch affects its ion exchange properties (Richter 1968;Jane et al 1996;Lin and Czuchajowska 1998;Rożnowski et al 2014), which was confirmed in the present study: during saturation, spelt monostarch phosphate absorbed ten times more iron(II) ions than natural starch, and about forty five times more copper (Table 1). Natural starch absorbed iron better than copper, while the monostarch phosphate absorbed copper more effectively (Table 1).…”

“…Neither phosphorylation nor mineral enrichment affected the flow index (n) ( Table 4). Rożnowski et al (2014) reported otherwise, finding that the enrichment of potato starch with iron considerably lowered the flow index, while similar treatment of corn starch increased this value. This shows that plant origin affects the rheology of enriched samples.…”

“…The native spelt starch and the spelt monostarch phosphate were enrichment with copper(II) ions according Przetaczek-Rożnowska et al (2012) method and iron(II) ions according procedure described by Rożnowski et al (2014). The starch sample (100 g) were stirred for 5 minutes with deionized water (250 cm 3 ) and filtered.…”