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1

Influences of magnesium ions in water on gelatinization characteristics of starch and its flocculation behaviors on particles

Tang Min, Niu Xiaoying, Wen Shuming

Physicochemical Problems of Mineral Processing

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2024

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Vol. 60, iss. 1

art. no. 178149

EN

It is inevitable for the occurrence or built-ups of disturbing cations, especially Ca2+ or Mg2+ ions, in process water during the flotation of iron oxides by using starch as flocculants. In addition to alkali concentrations and temperature, water quality could have an essential role in changing the physicochemical properties of the starch solution and consequently disturbing its flocculation performance on particles. This study aims to identify the effects of magnesium ions on the gelatinization characteristics of starch and its flocculation properties on particles through a series of tests, such as flotation tests, settling tests, size analyses, zeta potentials, powder contact angle, Fourier Transform Infra-Red (FTIR) and X-ray Photoelectron Spectroscopy (XPS) measurement. All results show that magnesium ions at ≤ 4 mmol/L have a positive role due to enlarging the sizes of the particle flocs and accelerating their settling rates. The occurrence of Mg2+ ions at higher concentrations during starch gelatinization only obtains a starch sol-gel with entangled configurations and preoccupied active sites, resulting in the slower settling rate of the particle flocs and less hydrophilicity on mineral surfaces. It could be attributed to the cross-link interactions of magnesium-based precipitates with the acidic groups, especially carboxyl groups on the starch remnants. The suitable acid/base interactions between Mg(OH)2/MgCO3 compounds with these groups in the starch suspension could be beneficial for enhancing the flocculation of hematite as they could build bridges among the pieces and enlarge their sizes as a “load carrier” for aggregation with minerals. However, too much cross-linking could reentangle the remnants, block their adsorption sites on mineral surfaces, and eventually, weaken the flocculation capacity of starch.

2

Starch gelatinization and hydrolysis in the apparatus with Couette-Taylor flow

Hubacz R., Ohmura N., Wroński S.

Inżynieria i Aparatura Chemiczna

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2010

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Nr 2

55-56

3

Vlianie sposoba polucenia kolloidnyh rastvorov krahmala na ih strukturu

Padohin V., Kockina N., Fedoseeva T.

Czasopismo Techniczne. Mechanika

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2008

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R. 105, z. 2-M

295-300

EN

The structure of gelatinized starch solutions obtained by joint action of mechanical deformations and heat at biopolymer in water-glycerol medium was under study. Our investigations showed sharp destruction of starch to be the result of its mechano-thermal gelatinization.

4

Effect of concentration on viscoelastic properties of potato starch gel

Witczak M., Juszczak L., Fortuna T.

International Journal of Applied Mechanics and Engineering

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2005

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Vol. 10, no spec

189-193

EN

The aim of present work was to study effect of concentration on viscoelastic properties of heating potato starch dispersions and starch gels. The complex viscosity, storage and loss moduli were monitored during heating of starch dispersion using rheometer RS 150 (Haake, Germany). The mechanical spectra of potato starch gels were also determined. The experiments were carried out at starch concentration of 2-8%. It was observed that significant rise of complex viscosity and storage and loss moduli occurs at 62.5 to 66oC and the peak of this parameters during heating was achieved at temperature range 65-69oC and they depend on starch concentration. Mechanical spectra of potato starch gels, show that in the whole applied range of frequency there was a domination of elastic properties over viscous features. However, the values of tangent of phase angle indicate at the applied conditions potato starch form weak gels. and constants of power-law equations describing storage and loss moduli dependence on frequency increase according to exponential function with starch concentration.

5

Processing conditions for micronization of peas (Pisum sativum) and an in-vitro evaluation of the product

Arntfield S.D., Zhang M.Z., Nyachoti C.M., Guenter W., Cenkowski S.

Technical Sciences / University of Warmia and Mazury in Olsztyn

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2004

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nr 7

27-38

EN

Tempering and storage conditions were investigated for the processing of peas using infrared heat (micronization). The criteria for evaluation of processing conditions included the extent to which starch was gelatinized, the extract viscosity of the peas and the availability of lysine in the peas. In the initial study using the pea (Pisum sativum) cultivar Croma, a tempering level of 24% moisture was selected for the micronization treatment as it resulted in significant increases (pŁ0.05) in starch gelatinization, while maintaining available lysine levels and reducing extract viscosity. With minor exceptions, which included a decrease in available lysine for the cultivar Carneval, similar results were obtained when these conditions were applied to four other pea cultivars (two yellow and two green) in a second study. Storage at room temperature (22oC) was able to preserve these characteristics, and there was no benefit to storing at a lower temperature of 4oC for up to 6 weeks. Differences in available lysine for the yellow Carneval and unknown cultivars, seen immediately after processing, were not a factor following storage. The production of micronized peas suitable for incorporation into animal feed is possible if the appropriate moisture content during tempering is selected.

PL

Badano wpływ nawilżania oraz warunków przechowywania grochu, który został poddany obróbce cieplnej w zakresie promieniowania podczerwonego (mikronizacji). Kryteria do oceny warunków przetwarzania obejmowały ilość skleikowanego krochmalu, lepkość ekstraktu z grochu oraz dostępność (dyspozycyjność) lizyny w grochu. W początkowych badaniach, używając grochu (Pisum sativum) odmiany Croma, wybrano poziom nawilżenia 24%, ponieważ wynikiem tego był znaczny (pŁ0.05) wzrost skleikowania krochmalu przy jednoczesnym utrzymaniu dyspozycyjności poziomu lizyny i obniżonej lepkości ekstraktu z grochu. Podobne rezultaty otrzymano, gdy takie same warunki przetwarzania były zastosowane w drugiej części eksperymentów dla czterech innych odmian grochu (dwie żółte odmiany i dwie zielone), z małym jednak wyjątkiem, gdy zanotowano obniżenie lizyny w odmianie Carneval. Przechowywanie grochu po mikronizacji w pokojowej temperaturze (22oC) zachowało otrzymane charakterystyki materiału, nie dając żadnych różnic w mierzonych właściwościach podczas przechowywania grochu w temperaturze 4oC przez 6 tygodni. Różnice w dostępności lizyny w żółtej odmianie Carneval i nieznanych odmianach, a oceniane zaraz po mikronizacji, zatarły się po kilkutygodniowym okresie przechowywania. Wyniki badań potwierdzają, że groch poddany mikronizacji może być użyty z powodzeniem w celach paszowych, jeżeli zostanie on nawilżony do właściwego poziomu przed mikronizacją.