• Korean Chemical Engineering Research
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• v.49 no.4
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• pp.475-479
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• 2011

Chitosan is a natural polymer that has many physicochemical(polycationic, reactive OH and $NH_2$ groups) and biological(bioactive, biocompatible, and biodegradable) properties. In this study, chitosan nanoparticles were prepared using poly-${\gamma}$-glutamic acid(${\gamma}$-PGA) as gelling agent. Nanoparticles were formed by ionic interaction between carboxylic groups in ${\gamma}$-PGA and amino groups in chitosan. Chitosan(0.1~1 g) was dissolved in 100 ml of acetic acid (1% v/v) at room temperature and stirred overnight to ensure a complete solubility. An amount of 0.1 g of ${\gamma}$-PGA was dissolved in 90 ml of distilled water at room temperature. Chitosan solution was dropped through needle into beaker containing ${\gamma}$-PGA solution under gentle stirring at room temperature. The average particle sizes were in the range of 80~300 nm. The prepared chitosan/${\gamma}$-PGA nanoparticles were used to examine their removal of several heavy metal ions($Cd^{2+}$, $Pb^{2+}$, $Zn^{2+}$, $Cu^{2+}$, and $Ni^{2+}$) as adsorbents in aqueous solution. The heavy metal removal capacity of the nanoparticles was in the order of $Cu^{2+}$ > $Pb^{2+}$ > $Cd^{2+}$ > $Ni^{2+}$ > $Zn^{2+}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.681-688
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• 1996

To investigate the effort of drying methods on the physicochemical properties of agar, gel strength, viscosity, melting and setting point, and phase transition by differential scanning calorimetery (DSC) during its heating were determined. In addition the structural differences of agar powder by scanning electron microscope (SEM) was examined. The most shortest onset temperature of gel strength increase was extruding method among any other methods. Viscosity of agar with hot air method, 400.00 cps at $45^{\circ}C$, was markedly increased, but with spraying and extruding ones were little change. The melting and setting point, and the temperature for maximum endothermic and enthalpy for agar with extruding one, $80.01^{\circ}C,\;36.05^{\circ}C\;and\;61.72^{\circ}C,\;0.73\;cal/g$, respectively, were lowest among the drying ones. But in the case of reheating after gelling, there were little change in all methods. Observing the surface structure of agar with SEM, extruding method showed the most unstable with absorptive property.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.673-676
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• 1998

Preparative conditions of high-gel strength agar from Gelidium amansii have been studied, The effect of NaOH pretreatment on the quality and yields of agar extracted from Gelidium amansli was examined. The Bel strength of agar extracted from C. amansii pretreated with NaOH was higher than that of agar extracted from G. amansii non-pretreated with NaOH. The gel strength of agar extracted from G. amansii was influenced by concentration, temperature and time of pretreatment with NaOH. It was found that the proper concentration, temperature and time of NaOH pretreatment to produce high-gel strength agar was $6\%$ NaOH, $80^{\circ}C$ and 2$\~$3 hrs. The principal sugars of agar extracted from G. amansli were galactose and 3,6-anhydrogalactose.

• Journal of the Korean Society of Food Culture
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• v.28 no.6
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• pp.664-673
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• 2013

This study was conducted to investigate the physicochemical properties of mung bean starch and the quality characteristics of mung bean starch gels supplemented with gelatin and isolated soy protein (0, 2, 5%) during storage at $5^{\circ}C$ for 0, 24, 48, and 72 hours. The swelling power of mung bean starch supplemented with gelatin did not significantly change, whereas those supplemented with isolated soy protein (ISP) significantly increased. The solubility of mung bean starch supplemented with gelatin and ISP, however, significantly increased with increasing concentration. In addition, the soluble amylose and soluble carbohydrate of mung bean starch supplemented with gelatin and ISP significantly decreased with increasing concentration. In terms of pasting properties measured by the Rapid Visco Analyzer (RVA), the pasting temperature of mung bean starch supplemented with gelatin and ISP was not significantly different, whereas peak viscosity, minimum viscosity, final viscosity, breakdown, and consistency decreased. DSC thermograms showed that the onset temperature of mung bean starch supplemented with gelatin and ISP did not significantly change, whereas the enthalpy increased with the addition of 5% ISP. The lightness (L) and redness (a) of mung bean starch gels supplemented with gelatin, ISP, and without additives increased during cold storage, whereas the yellowness (b) decreased. The addition of gelatin and ISP suppressed changes in L, a and b of mung bean starch gel during cold storage. Synereses of mung bean starch gel supplemented with gelatin and ISP was lower than that without additives, with the addition of gelatin suppressing synereses more than ISP. The addition of gelatin and ISP also suppressed increases in hardness, chewiness, and gumminess of mung bean starch gels during cold storage. In the sensory evaluation, the addition of gelatin and ISP suppressed increases in hardness and brittleness of mung bean starch gels during cold storage. The addition of 2%, 5% gelatin and 2% ISP also suppressed a decrease in the overall acceptability of mung bean starch gels during 24-48 hr cold storage. Thus, the addition of 2-5% gelatin and 2% ISP to mung bean starch is appropriate for suppressing the quality deterioration of 24-48 hr cold-stored mung bean starch gels.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.5
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• pp.721-733
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• 2019

Objective: The objectives of this study were to investigate the thermal gelation properties and molecular forces of actomyosin extracted from two classes of chicken breast meat qualities (normal and pale, soft and exudative [PSE]-like) during heating process to further improve the understanding of the variations of functional properties between normal and PSE-like chicken breast meat. Methods: Actomyosin was extracted from normal and PSE-like chicken breast meat and the gel strength, water-holding capacity (WHC), protein loss, particle size and distribution, dynamic rheology and protein thermal stability were determined, then turbidity, active sulfhydryl group contents, hydrophobicity and molecular forces during thermal-induced gelling formation were comparatively studied. Results: Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that protein profiles of actomyosin extracted from normal and PSE-like meat were not significantly different (p>0.05). Compared with normal actomyosin, PSE-like actomyosin had lower gel strength, WHC, particle size, less protein content involved in thermal gelation forming (p<0.05), and reduced onset temperature ($T_o$), thermal transition temperature ($T_d$), storage modulus (G') and loss modulus (G"). The turbidity, reactive sulfhydryl group of PSE-like actomyosin were higher when heated from $40^{\circ}C$ to $60^{\circ}C$. Further heating to $80^{\circ}C$ had lower transition from reactive sulfhydryl group into a disulfide bond and surface hydrophobicity. Molecular forces showed that hydrophobic interaction was the main force for heat-induced gel formation while both ionic and hydrogen bonds were different significantly between normal and PSE-like actomyosin (p<0.05). Conclusion: These changes in chemical groups and inter-molecular bonds affected protein-protein interaction and protein-water interaction and contributed to the inferior thermal gelation properties of PSE-like meat.

• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.99-106
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• 1998

Two kinds of carrageenan were extracted from red seaweeds, Tichocarpus crinitus, collected in The Peter the Great Bay of Russia on August, 1996. One is KC1-insoluble carrageenan and another is KC1-soluble carrageenan. The yield of KC1-insoluble carrageenan was 17.15%, which is composed of 18.06% total sulfate, 5.61% protein, 3.51% K+, 0.49% Na+, 1.66% Ca2+, 54.26% galactose, 4.68% xylose, trace of mannose and glucose. The yield of KC1-soluble carrageenan was 3.52%, which is composed of 24.06% total sulfate, 5.2% protein, 5.32% K+, 0.16% Na+, 2.80% Ca2+, 33.54% galactose, 5.48% xylose, 4.32% mannose, trace of glucose. But rhamnose was not detected in both case. FT-IR spectrum showed that the KC1-insoluble carrageenan was kappa-type carrageenan and that KC1-soluble carrageenan was lambda, iota hybrid-type carrageenan. KC1-insoluble carrageenan was very weakly formation the gel compared with KC1-insoluble carrageenan from other red seaweeds. So we investigated viscosity. Both type carrageenan was stable in the temperature until 9$0^{\circ}C$, 1 hr. The viscosity of the solution of KC1-insoluble carrageenan was increased to about two folds by K+, but was not changed by Ca2+. The viscosity of the solution of KC1-soluble carrageenan was reduced by K+ and Ca2+. Both of them was stabilized in alkali but was reduced in comparison with acid conditions. In this study, both carrageenan was expected as thickening agent than gelling agent for food additives.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.55-61
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• 1997

In order to effectively utilize the fish and squid skin wastes derived from marine processing manufacture, the skin wastes of some pelagic fishes such as yellowfin sole, red cod, cod, Allaska pollack and flying squid were screened for the raw material of edible gelatin and studied some properties of those gelatins. The content of total collagen in the red cod skin was the highest (28.4 g/100 g wet skin), while that in the flying squid skin was the lowest (11.1 g/100 g wet skin) and those of another fishes were similar. Acid soluble collagens in the skins of the fishes and flying squid were $68.9\~84.8\%\;and\;44.3\%$, respectively. But showed no difference in the amino acid composition between acid soluble and insoluble collagens. Those collagens were consisted $\alpha\;and\;\beta$ chain and $\alpha$ chains extracted from fish skins except red cod and flying squid skins were hetero. The collagen of yellowfin sole skin exhibited slightly higher denaturation temperature $(25.4^{\circ}C)$ and also physical properties such as gel strength, melting point and gelling point were better than those of the other species.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.758-766
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• 2015

Dextran is a generic term for a bacterial exopolysaccharide synthesized from sucrose and composed of chains of D-glucose units connected by ${\alpha}$-1,6-linkages by using dextransucrases. Dextran could be used as vicosifying, stabilizing, emulsifying, gelling, bulking, dietary fiber, prebiotics, and water holding agents. We isolated new strain capable of producing dextran from Korean traditional kimchi and identified as Leuconostoc sp. strain JYY4. Batch fermentation was conducted in bioreactor with a working volume of 3 L. The media was MMY and 15% (w/v) sucrose. Mineral medium consisted of $3.0g\;KH_2PO_4$, $0.01g\;FeSO_4$, $H_2O$, $0.01g\;MnSO_4$, $4H_2O$, $0.2g\;MgSO_4\;7H_2O$, 0.01 g NaCl, $0.05g\;CaCl_2$ per 1 liter deionized water. The pH of media was initially adjusted to 6.0. The inoculation rate was 1.0% (v/v) of the working volume. Temperature was maintained at $28^{\circ}C$. The agitation rate was 100 rpm. The production pattern of dextran was associated with the cell growth. After 24 hr dextran reached its highest concentration of 59.4 g/L. The sucrose was consumed completely after 40 hr. Growth reached stationery phase when sucrose became limiting, regardless of the presence of fructose or mannitol. When the specific growth rate was 0.54 hr-1, utilization averaged 5.8 g/L-hr. The yield and productivity of dextran were 80% and 2.0 g/L-hr, respectively. Dextrans produced by were separated to two different size by an alcohol fraction method. The size of high molecular weight dextran (45% alcohol, v/v), less soluble dextran, was between MW 500,000 and 2,000,000. Soluble dextran (55% alcohol, v/v) was between 70,000 and 150,000. The molecular weight average of total dextran (70% alcohol, v/v) was between 150,000 to 500,000. The enzymatic hydrolyzates of total dextran of ATCC 13146 showed branched dextrans by Penicillium dextranase contained of glucose, isomaltose, isomaltotriose, and isomaltooligosaccharides greater than DP4 (degree of polymerization) that had branch points. Compounds greater than DP4 were branched isomaltooligosaacharides. Hydrolysates by the Lipomyces dextranase produced the same composition of oligosaccharides as those by Penicillin dextranase.

• Applied Biological Chemistry
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• v.39 no.2
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• pp.134-139
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• 1996

In order to effectively utilize marine animal skin wastes in marine processing manufacture, conger eel skin, file fish skin and arrow squid skin as raw material of edible gelatin were screened. Conger eel skin was the highest in the collagen content, followed by Ole fish skin and arrow squid skin, in the order named. In the fish skins, the soluble and insoluble collagens occupied $67.4%{\sim}72.3%\;and\;27.7{\sim}32.6%$, respectively, and in the arrow squid skin, 30.4ft and 69.6ft, respectively. No difference in the amino acid composition between soluble and insoluble collagens was detected. Collagen from the marine animal skin catched in coasted and offshore water in Korea consisted ${\alpha}$ chain and ${\beta}$ chain, and ${\alpha}$ chain were hetero type. The sum of proline and hydroxyproline contents in conger eel skin collagen was higher than that in the other skin collagens, while was lower than that pork skin collagen. Conger eel skin collagen exhibited a higher denaturation temperature in solution and a higher degree of proline hydroxylation, compared with skin collagen of the respective species. The physical properties such as gel strength, melting point and gelling point of conger eel skin gelatin were superior to those of file fish skin and arrow squid skin gelatins.

• Biomolecules & Therapeutics
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• v.6 no.2
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• pp.213-218
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• 1998

A novel in situ-gelling and mucoadhesive acetaminophen liquid suppository was developed to improve the patient compliance of conventional solid suppository. In this study, acetaminophen liquid suppository, Likipe $n_{R}$, ［aminophen/Poloxamer 407/Poloxamer 188/so4ium alginate (5/15/19/0.6%)] with relation temperature at 30-36 "C and suitable gel strength and bioadhesive force, dissolution pattern similar to conventional solid type suppository, Suspe $n_{R}$, was developed. Furthermore, the bioequivalence of two acetaminophen products was evaluated in 16 normal male volunteers (age 22-27 yr, body weight 56-72 kg) following sidle rectal administration. Test product was Likipe $n_{R}$ suppository (Dong-Wha Pharm. Corp., Korea)and reference product was Suspe $n_{R}$204-212 suppository (Hanmi Pharm. Corp., Korea). Both products contain 125 mg of acetaminophen. Four Suppositories of the test and the reference product were administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). The determination of acetaminophen was accomplished using HPLC. Average drug concentrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products (p>0.05); the area under the curve to last sampling time (24 hr) (AU $Co_{-2}$4h/) (30.14$\pm$8.64 vs 27.98$\pm$ 6.53 $\mu$g .h/ml), maximum plasma concentration ( $C_{max}$) (3.29$\pm$0.87 vs 3.60$\pm$0.66 $\mu$g/ml) and time to maximum plasma concentration ( $T_{max}$) (2.91 $\pm$0.55 vs 2.69$\pm$0.60 h). The differences of mean AUCo $_{24h}$, C-a. and T-between the two products (7.18%, 9.58% and 7.53%, respectively) were less than 20%. The power (1-7) and treatment difference ($\Delta$) for AU $Co_{24h}$, $C_{max}$ and $T_{max}$ were more than 0.8 and less than 0.2, respectively at $\alpha$=0.1. The confidence limits for AU $Co_{24h}$, $C_{max}$ and $T_{max}$ (-0.81 ~13.55%, -1.56~ 17.60 and -3.81 ~18.87%, respectively) were less than $\pm$ 20% at $\alpha$=0.1. These results suggest that the bioavailability of Likipe $n_{R}$ suppository is not significantly different from that of Suspe $n_{R}$ suppsitory. Therefore, two products are bio-equivalent based on the current results.results.lts.sults.results.lts.