• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3665-3676
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• 2023

The use of ion exchange resins to remove ionic impurities from solution is prevalent in industrial process systems, including in the primary heat transport system (PHTS) purification circuit of nuclear power plants. Despite its extensive use in the nuclear industry, our general understanding of ion exchange cannot fully explain the complex chemistry in ion exchange beds, particularly when operated at or near their saturation limit. This work investigates the behaviour of mixed-bed ion exchange resin, saturated with species representative of corrosion products in a CANDU (Canadian Deuterium Uranium) reactor PHTS, particularly with respect to iron chemistry in the resin bed and the removal of lithium ions from solution. Experiments were performed under deaerated conditions, analogous to normal PHTS operation. The results show interesting iron chemistry, suggesting the hydrolysis of cation resin bound ferrous species and the subsequent formation of either a solid hydrolysis product or the soluble, anionic Fe(OH)₃^-.

• Applied Biological Chemistry
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• v.44 no.4
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• pp.219-223
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• 2001

Effects of hemoglobin (Hgb) concentration and degree of hydrolysis (DH) of Hgb on the separation of heme-iron were examined to produce highly enriched heme-iron from Hgb hydrolysate. Separation efficiency of Hgb hydrolysate with different DH was studied at wide pH range (pH $1.0{\sim}11.0$). Separation efficiency expressed as heme-iron/peptide ratio increased with decreasing Hgb concentration. When 5% Hgb (pH 10.0) was hydrolyzed using commercially available Esperase for 5 h at $50^{\circ}C$, DH was 25%. The precipitation of heme-iron-enriched peptides were remarkably high at pH range $3{\sim}6$. Optimal pH range for heme-iron with high heme-iron/peptide ratio shifted to acidic pH with increasing DHs of Hgb. The enriched heme-iron fraction in the precipitates showed a single band through urea-SDS-PAGE, with a molecular mass of 1 kDa. In the dry heme-iron product produced in a pilot bioreactor, content of heme-iron and heme-iron/peptide ratio were 27.1 and 38.7%, respectively, and production yield was 9.3%.

• Food Science of Animal Resources
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• v.30 no.6
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• Food Science and Preservation
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• v.23 no.5
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• pp.753-757
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• 2016

In this study, enzyme (thermoase) hydrolysis was applied to the porcine blood order to increase the iron content and solubility. It was confirmed that content of iron was increase up to 158.11 mg/100 g porcine powders after 0.2% thermoase treatment at $60^{\circ}C$ during 4 hr. The solubility of porcine blood powders was higher than other enzyme (various protease), temperature, reaction time. This optimized conditions were also worked to the in vitro iron bioavailability rate increasement, the bioavailability of hydolyzed porcine powders was 3-fold higher than that of an iron supplement on the market. These results indicate the possibility of porcine blood powder in iron supplements market as natural material. Also utilizing of reduced porcine blood will be possible to improve environmental issues.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.130-133
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• 2003

A method for separating heme-iron from hemoglobin (Hgb) hydrolysate by dialysis was developed. Recovery of heme-iron increased with increasing Hgb concentration, whereas rejection of peptide and separation effciency expressed by HP ratio (heme-iron/peptide) did not show significant differences. HP ratio increased with increases in the degree of hydrolysis of Hgb and $KH_2PO_4$ concentrations of dialysis solution. Recovery of heme-iron decreased with increase in the pH of dialysis solution due to wash-out of heme-iron across the dialysis membrane caused by increase in solubility of heme-iron. Rejections of peptide were 74.5 and 87.5% (2 and 5 kDa of cut off size, respectively), whereas recovery of heme-iron decreased from 86.5 (2 kDa) to 63.1% (25 kDa). Amounts of heme-iron and peptide of dried heme-iron product were 21.7 and 77.0%, and HP ratio and production yield were 28.2 and 6.5%, respectively.

• Journal of Applied Biological Chemistry
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• v.55 no.4
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• pp.263-266
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• 2012

Isolation of iron and calcium-binding peptides derived from cottonseed meal protein (CMP) hydrolysates was investigated. The degree of hydrolysis of CMP by Flavourzyme was monitored using trinitrobenzenesulfonic acid method and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Enzymatic hydrolysis of CMP for 12 h was sufficient for the preparation of CMP hydrolysates, and the hydrolysates were membrane-filtered under 3 kDa as a molecular weight. The filtered solution was fractionated using Q-Sepharose fast flow, Sephadex G-15, and reversed phase-high performance liquid chromatography for iron and calcium-binding peptides. As a result, F51 fraction was obtained as the best candidate for calcium and iron chelation, and the isolated iron and calcium-binding peptides can be used as functional food additives, similar to iron and calcium supplements.

• Tribology and Lubricants
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• v.17 no.3
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• pp.171-178
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• 2001

In order to elucidate the lubricating mechanism of polyolester base oils [POEs], the wear characteristics of 27 kinds of polyolester base oils including mixed POEs were investigated. Their wear results were discussed in terms of the effect of molecular structure on wear performance and compared with those of mineral oil. In addition, the adsorption ability of POEs to reduced iron and their hydrolysis rates were measured and the effect of their molecular structures on the adsorptivity and hydrolysis rate of POEs was discussed, respectively. Finally, the lubricating mechanism anlyzed from these results of wear characteristics, adsorptivity and hydrolysis rate was proposed. That is to say, POEs are firstly adsorbed to friction surface and decomposed by hydrolysis or thermal degradation. Fatty acids obtained by degradation of POEs form adsorption film on friction surface. The larger become cohesive ability among fatty acid molecules in the adsorption film, the better gets the wear performance of POEs.

• Food Science and Preservation
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• v.23 no.3
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• pp.413-421
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• 2016

The aim of this study was to investigate physicochemical properties of porcine blood hydrolyzed by proteases under various conditions for utilization as a food source. Five kinds of proteases (Alcalase, Neutrase, Protex-40L, PTPF-1430, and KMFP-15) were tested at different concentrations (0.1, 0.2, and 0.3%, w/v) during hydrolysis at 55 for 4 hr. Hydrolysis with $^{\circ}C$ KMFP-15 showed the lowest pH by 7.3. The highest soluble solid ($24.3^{\circ}Brix$) and free amino acid (4,944 mg%) contents were obtained by hydrolysis with KMFP-15 (w/v) at 0.2% addition level, which was not significantly different from the sample hydrolyzed at 0.3% level. Under the optimal condition of KMFP-15 at 0.2%, porcine blood was hydrolyzed at 60 up to 8 hr. The $^{\circ}C$ free amino acid content reached the highest at 4 hr, and then decreased with longer hydrolysis time. Under the optimal hydrolysis conditions, porcine blood hydrolysis powder had plenty of crude proteins, amino acids, and minerals, including iron, potassium, and zinc. The results showed that porcine blood could be utilized as an useful source of food supplement. The optimum conditions of hydrolyzing porcine blood, using 0.2 KMFP at $60^{\circ}C$ for 4 hr, can be used in the commercial production of protein supplements, amino acid sources, and iron fortifying agents.

• Journal of the Korean Ceramic Society
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• v.17 no.1
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• pp.35-41
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• 1980

Alumina extraction from raw Hadong kaolin with sulfuric acid was studied to obtain relatively pure alumina. Factors as acid concentration, heating temperature and conditions of ammonium alum crystal formation from extracted solution are also surveyed and most of iron oxide in kaolin is eliminated in crystallization of ammonium alum. Pure crystal obtained from the extracted solution with ammonium sulfate is relatively free from iron containment in mother liquor. Alumina in ammonium alum crystal is converted to gibbsite form after complete hydrolysis in ammonia gas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1162-1166
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• 2013

Proteins from sunflower seeds were hydrolyzed with Alcalase and Flavourzyme to isolate iron-binding peptides. The optimal hydrolysis conditions were determined. Hydrolysates were filtered under a 3 kDa membrane and iron-binding peptides separated from the hydrolysates using ion exchange and gel permeation chromatographic methods. A fraction with the highest iron-binding activity (Fe/peptide, 0.69), F22, was obtained. These results suggest that fractions isolated from sunflower seed protein hydrolysates can be applied toward the production of iron supplements.