• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.999-1004
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• 2002

In this study, pork loin was cured for 20 days in the 2$^{\circ}C$ curing solution with the salt concentration of 3, 5, 7 and 9% respectively, and the effects of salt concentration and curing time on myofibrillar protein extractability (MPE), myofibrillar fragmentation index (MFI), water holding capacity (WHC), salt content, and palatability of pork loin were investigated. The pork loin cured in the 3, 5 and 7% curing solution showed the increased level of MPE and WHC up to 20 days of curing time, and the increased level of MFI up to 16 days of curing time. Also those values increased with the increasing salt concentration, regardless of the curing time. The pork loin cured in the 9% curing solution did not show any consistency in the results. The boiled cured pork loin showed better color up to 16 days of curing time, as the salt concentration of curing solution increased. The color of pork loin cured in the 3% curing solution was not uniform. The pork loin cured in the 9% curing solution showed good color, but its flavor and palatability were unacceptable. The palatability of pork loin could be improved significantly by curing it in the 5% curing solution for 16 days, and in the 7% curing solution for 12 days.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.447-452
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• 1988

In order to study effect of freezing rates on the quality changes such as pH, TBA value, free fatty acids and protein extractability, cylindrical chopped beef logs with 10cm of diameter and 10cm of height were frozen at three freezing rates(0.97cm/hr, 2.05cm/hr, 3.71cm/hr)using air blast freezer. Physicochemical changes of frozen meat were investigated during forzen storage at $-20^{\circ}C$ for 16weeks. Results on pH change showed $0.1{\sim}0.2unit$ increase at the 16th week of the frozen storage and the change was smaller with the increasing freezing rates. Free fatty acids content and TBA value also were increased during forzen storage, but they were minimal at 3.71cm/hr freezing rate. Correlation coefficient between TBA value and free fatty acids content were highly significant(r=0.804). After 16weeks of storage, extractibilities of salt soluble protein were decreased by 17.7%, 6.1% and 1.6% at freezing rates of 0.97, 2.05 and 3.71cm/hr, respectively. On the other hand, extractabilities of water soluble protein were decreased by 26.0%, 21.2% and 18.5%, respectively. The effect of freezing rates on the protein extractability appeared to be greater in salt soluble protein than in water soluble protein, but freezing denaturation was more rapid in water soluble protein.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1120-1127
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• 1998

An attempt was made in this study to investigate the optimum condition of washing for preparation of mackerel surimi by alkaline washing of 1, 3, 5, and 7 times under atmospheric (760), 660, and 560 mmHg pressure. The qualities of surimis were examined by analyzing the factors such as water content, crude lipid, pH, volatile basic nitrogen (VBN), expressible drip, protein extractability, $Mg^{2+}-$, $Ca^{2+}-$ and EDTA-ATPase activity, transglutaminase (TGase) activity, gel strength and color. The contents of moisture, crude lipid, pH and VBN in surimis prepared by alkaline washing under atmospheric, and reduced pressure went up to $72.0{\sim}72.9%$, $4.8{\sim}5.7%$, $6.9{\sim}7.0$ and $6.7{\sim}7.0\;mg/100\;g$, respectively. Protein extractability, ATPase activity and TGase activity were highest in surimis prepared by alkaline washing under 560 mmHg. Gel strengths of surimi setting gel and cooked gel from five times washing under 560 mmHg were 420 g cm (atmospheric, 330 g cm) and 485 g cm (atmospheric, 412 g cm), respectively. For the preparation of mackerel surimi, optimum washing condition was five times washing under 560 mmHg.

• KSBB Journal
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• v.20 no.3
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• pp.238-243
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• 2005

Succinic acid has recently been drawing much interest as a raw material for biodegradable polymer. In this study acetic acid was removed by reactive extraction with various amines dissolved in various diluents. Distribution coefficients were determined as the kind of amines, diluents, and pHs of continuous phase. The extraction capacity increased with the polarity of diluent and the decrease of pH from the artificial binary solution. Based on the different extractability for succinic acid and acetic acid from the artificial binary solution, the removal of acetic acid from fermentation broth was investigated using various amines and diluents. In addition, the extractability and selectivity of CLA for succinic acid and acetic acid from fermentation broth were higher than that of straight solvent extraction.

• Journal of the Korean Chemical Society
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• v.19 no.5
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• pp.343-350
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• 1975

About 20${\sim}$100${\mu}g$ iridium have been extracted quantitatively as stannous-chloro Complex from aqueous solution by Alamine-336, a high molecular weight tertiary amine, dissolved in benzene. The extractability was confirmed by radioactive tracer of iridium-192. The spectrophotometric measurements of the extracted species at 322.5 nm indicate the feasibility of this method to be used as an analytical procedure for the determination of micro amount of iridium. An anion model of stannous-chloro complex of iridium has been postulated to account for the extraction mechanism.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.453-456
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• 2010

The structural and energetic preferences of thiacalix[4]biscrown-5 with and without alkali metal ions ($Na^+$, $K^+$, $Rb^+$, and $Cs^+$) have been theoretically investigated for the first time using molecular dynamic (MD) simulations and density functional theory (MPWB1K/6-31G(d)//B3LYP/6-31G(d)) methods. The formation of the metal ion complex by the host is mainly driven by the electrostatic attraction between crown-5 oxygens and a cation together with the minor contribution of the cation-$\pi$ interaction between two facing phenyl rings around the cation. The computed binding energies and the atomic charge distribution analysis for the metal binding complexes indicate the selectivity toward a potassium ion. The theoretical results herein explain the experimentally observed extractability order by this host towards various alkali metal ions. The physical nature and the driving forces for cation recognition by this host are discussed in detail.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.78-84
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• 2016

The antioxidant activity of silkworm powder treated by proteolytic enzyme was investigated. Total protein content of silkworm power was assayed using BCA, Bradford assays and SDS-polyacrylamide gel electrophoresis (PAGE) with alkaline protease treatment conditions including temperature and pH. The optimum condition of alkaline protease treatment for silkworm powder was found to be $60^{\circ}C$ and pH 7. The alkaline protease treatment resulted in increased contents of free amino acids, total polyphenol and total flavonoid compared to control group. The silkworm hydrolysates showed excellent antioxidant activities in various in vitro models such as 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2 - azino-bis(3-ethylbenzthiazoline-6)-sulfonic acid (ABTS) radical scavenging activity. These results provide useful information for using silkworm powder as an ingredient in functional foods and for exploiting alkaline protease treatment to improve the extractability and bioactivity of a raw material.

• Applied Biological Chemistry
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• v.33 no.4
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• pp.282-286
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• 1990

To extract insoluble proteins of soymilk residue by microorganism the soymilk residue was treated with crude enzyme solution from Bacillus subtilis IAM 1071 natto. Optimum conditions of pH, temperature, and digestion time were determined, and amino acid composition of the extract was obtained at $45^{\circ}C$. Under optimum conditions, the extractability with natto reached to 65% in 15hrs. The contents of essential amino acids of extract were high and specially, S-containing amino acids including methonine and cysteine and Lysine content were high.

• Carbon letters
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• v.26
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• pp.43-50
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• 2018

In this research, a novel and efficient quinoline thioacetamide functionalized magnetic graphene oxide composite ($GO@Fe_3O_4@QTA$) was synthesized and utilized for dispersive magnetic solid phase preconcentration of Cd(II) and Ni(II) ions in urine and various food samples. A number of diverse methods were employed for characterization of the new nanosorbent. The design of experiments approach and response surface methodology were applied to monitor and find the parameters that affect the extraction performance. After sorption and elution steps, the concentrations of target analytes were measured by employing FAAS. The highest extraction performance was achieved under the following experimental conditions: pH, 5.8; sorption time, 6.0 min; $GO@Fe_3O_4@QTA$ amount, 17 mg; 2.4 mL $1.1mol\;L^{-l}$ $HNO_3$ solution as the eluent and elution time, 13.0 min. The detection limit is 0.02 and $0.2ng\;mL^{-1}$ for Cd(II), and Ni(II) ions, respectively. The accuracy of the new method was investigated by analyzing two certified reference materials (sea food mix, Seronorm LOT NO 2525 urine powder). The interfering study revealed that there are no interferences from commonly occurring ions on the extractability of target ions. Finally, the new method was satisfactorily employed for rapid extraction and determination of target ions in urine and various food samples.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.442-449
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• 2000

The bioremediation is an economic technology to remove the organopollutants from soil. It is often found that the remediation could not remove the compounds below the levels determined by vigorous extractions as required by regulatory agencies. The reason for the reduced bioavailability with increasing time of aging has been accredited to the sequestration of the compounds in remote sites within or between soil particles. Then, the aging could be defined as the time-dependent sequestration. Partitioning and entrapment have been suggested as mechanism for aging. The rate and extent of the sequestration varies among dissimilar soils. The bioavailability of aged pollutants in soil could be measured by bioassays, mild solvent extraction, and soild-phase extractions. The sequestration could be affected by many factors including various soil properties, wetting and drying cycle, and the presence of cosolutes and NAPLs etc. The bioavailability and sequestration should be considered to determine the environmentally acceptable endpoint.