• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.5
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• pp.542-548
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• 2018

We investigated the effects of Na-alginates's average molecular weight (AMW), their concentrations and divalent metal ions on hydrophobic interaction of solution of Na-alginates in sea tangle produced Saccharina japonicus in East Coast of Korea. As the AMWs of Na-alginates decreased, the formations rates of hydrophobic micro domains and pre-micelles between intermoleculars of Na-alginates were increased. The pre-micelles between Na-alginates chains fully were formed when their concentrations reached 0.2%. In the effects of $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ on the hydrophobicity of Na-alginates solution, when the AMWs of Na-alginates were increased, the formation rates of hydrophobic micro domains produced by $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ in alginates chains were increased. When $Ca^{{+}{+}}$ and $Mg^{{+}{+}}$ concentrations that were needed to form gels of alginates solutions were insufficient, the formations of pre-micelle in alginates having large AMW were more incomplete than those of small AMW. In the increasing range from 0.01 to 0.1 mM in divalent metal ion concentration, the formation rate of pre-micelle in alginates solution added $Ca^{{+}{+}}$ were more faster than that of $Mg^{{+}{+}}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.340-345
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• 2003

In order to choose the manufacturing method for extracting alginates from sea tangle, Laminaria japonica, three methods were applied. In Method I, alginates were extracted with NaOH solution from sea tangle powder and extracted alginates were precipitated and converted to alginic acid by $CaCl_2$ and HCI solution. Then alginic acid was converted to sodium alginates with $Na_2CO_3$ solution. Sodium alginates were precipitated with methyl alcohol and were resolved with hot water and this step was repeated three times. Method II was same to Method I except final step including that sodium alginates were precipitated and washed with methyl alcohol three times. Method III included that sodium alginates were extracted with $Na_2CO_3$ solution from sea tangle powder then sodium alginates were precipitated and washed with methyl alcohol three time. Extracting time increased with Increasing extracted alginates amounts but increasing rates were below $0.4\%/h.$ Alginates amounts recovered by Method III showed above 2 times more to those by Method I and II. Extracting time increased with increasing ash amount of sodium alginates but increasing rates were below $0.1\%/h.$ and that of sodium alginates extracted by Method III showed higher value $(5\%)$ than those by Method I and II. In the sodium alginates prepared by Method III, the amount of ash in alginates dried by air was $34.4\%,$ that by vacuum freeze drying was $47.8\%.$ Extracting time increased with decreasing average molecular weight (MW) and degree of polymerization (DP) of sodium alginates, MW and DP of alginates prepared by Method III were higher than those by Method I and II In same extracting time. Extracting time increased with decreasing rate of apparent viscosity change (SAV) of alginates solution, and SAV of alginates prepared by Method III showed higher value than those by Method I and II in same extracting time. SAV of alginates dried by air was higher than that by vacuum freeze drying. Relating equation among SAV MW and DP were MW = 60.066 (SAV) -93.950, DP =309.760 (SAV) -485.084 and MW = 0.914 (DP)+0.213.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.1-6
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• 2004

In preparing sodium alginates from sea tangle (Laminaria japonica) powder using the Mexican process, alkaline extraction, conversion to alginic acid and reversion to sodium alginates were used to increase purity. The effect of hot water treatment and dialysis on measuring the average molecular weight of sodium alginates were investigated. Intrinsic viscosity and average molecular weight of sodium alginates after dialysis were higher than those before dialysis. Average molecular weight of sodium alginates treated with hot water was higher than that without. Hot treatment has little effect on the ash content of sodium alginates. Ash content of sodium alginates before dialysis were $27-30\%$ those after dialysis were $10\%.$ After dialysis, Na content was highest $(89-91\%),$ K was $11-12\%,$ Ca was $1.9\%,$ and Mg was $0.05\%.$ Ash content of alginates had little effect on average molecular weight. SAV (slope of apparent viscosity) of alginates solution after dialysis showed higher values than before. SAV of the alginates with hot water treatment were higher than without treatment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.664-668
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• 1999

The extracting conditions of alginates from sea tangle were evaluated by measuring water vapor permeability (WVP) and tensile properties of alginate film to obtain basic data of making an edible and biodegradable film. The alginates were extracted with $1\%,\;3\%$ and $5\%$ sodium carbonate ($Na_2CO_3$) for 1, 3, 5 and 10 hours, and the alginate film was made with various plasticizers. The higher concentration of $Na_2CO_3$ solution showed the lower viscosity and polymerization degree of alginate and the film prepared with alginates having low viscosity showed the higher WVP. The extracting hours had little effect on the WVP and the elongation of alginate film, but the polymerization degree of alginates directly affected the tensile strength of the film. The addition of sorbitol and polyethylene glycol as a plasticizer lowered the WVPs and the elongation of alginate film.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.146-151
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• 1996

For the purpose of production of oligosaccharides from alginates, a bacterium was isolated from seaweed, and then an enzyme which degraded alginates was obtained from the bacterium. A specific activity of the enzyme was shown in G-rich block and Na-alginate (Wako Co.) as a result of reaction between the enzyme and six types of alginates (G-rich block, M-rich block and 4 commercial Na-alginate). Degradation products were prepared from the Na-alginate (Wako Co.) by the enzyme. The oligosaccharides were fractioned by Sephadex G-25 and Bio-gel P-2 and identified on a thin layer chromatography (TLC). Degree of polymerization (DP) of the oligosaccharides was shown from 2.6 to 7.5.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.995-1002
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• 2000

In order to Develop a low Na functional kimchi using sea tangle, the Na-binding capacity of alginate in sea tangle along with other dietary fibers was evaluated in vitro. The adding type and amount of the sea tangle that contains alginate in kimhi and characteristics of the sea tangle added kimchi were also studied. Na-binding capacity of various dietary fibers such as cellulose, pectin, gun gum, carageenan, alginates (sodium alginate, alginate, alginate from sea tangle) was measured by equilibrium dialysis method in pH 2 and pH 7 in vitro. Gua gum, carageenan and a group of alginates effectively bound to Na+ Espacially sodium alginate showed high Na-binding capacity of 29.2% in pH of stomach (pH 2.0) and 33.8% in pH of small intestine (pH 7.0), however, the alginate extracted from sea tangle could not bind Na in PH of stomach (pH 2.0), but 27.4% in pH of small intestine (pH 7.0) condition. The content of alginate in sea tangles (dried sea tangle, salted sea tangle and washed salted sea tangle) was 19.8 ~ 22.2% on dry matter basis. The sea tangle added kimchi was prepared with the addition of the flake type (0.5$\times$3 cm) of sea tangle with a quantity of 30% in kimchi from the data of the sensory analysis. The addition of the sea tangle to the kimchi increased the content of soluble dietary fiber, suggesting the Na-binding capacity increased. The sea tangle added kimchi (SK) and sea tangle and fermented anchovy added kimchi (SAK) showed higher levels of reducing sugar and acidity than the control kimchi (CK). In quantitative descriptive analysis (QDA) SK and SAK showed higher score in overall acceptance, and lower score in acidic order than CK, however, SK showed less moldy taste and more fresh acidic taste than SAK.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.582-586
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• 1999

The processing conditions for producing and edible alginate film from sea tangle were investigated by measuring water vapor permeability (WVP), tensile properties and colors of film. The alginates were extracted with $3\%$ sodium carbonate ($Na_2CO_3$) solution for 5 hrs, and the alginate films were prepared with extracted sodium alginates, D-gluconic acid lactone, $CaCO_3$ and various plasticizers, As the concentration of alginate in making the film was increased, the WVP and elongation of the film were decreased and the tensile strength was increased. The higher amount of plasticizer showed the higher WVP and elongation, and the order of various plasticizers in increasing the WVP and elongation of the film was glycerol, polyethylene glycol, and sorbitol. The addition of sorbitol in the film showed the highest value (89.57) in lightness of Hunter color system and the film added polyethylene glycol had the highest values (-1,12 and 11.4) in redness and yellowness.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1035-1039
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• 1998

Phase separation is the typical phenomenon in protein-polysaccharide mixtures because of thermodynamic incompatibility between two macromolecules. Phase separations of casein-alginate-water systems were investigated by using phase diagram under varying pH (6, 8 and 10) and NaCl concentrations (0, 0.25 and 0.5 M). Incompatibility decreased with increasing pH and decreasing NaCl concentration. Molecular weight of alginates did not significantly affect the phase diagram of casein-alginate-water systems. The results strongly suggested that compatibility of casein and alginate involved electrostatic interactions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.747-752
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• 2004

Alginates were extracted from the Laminaria religiosa, Undaria pinnatifida, and Hizikia fusiforme by using four different extraction methods and compared the yields of alginate. Acid-alkali soluble alginate (AASA) extraction method from Undaria pinnatifida resulted in the best yield of alginate among the seaweeds. The optimal condition for extracting alginate from Laminaria religiosa was 0.4 N H$_2$SO$_4$ and 3% NaCO$_3$ concentrations at the AASA extraction method. The alginate yields of hot water extractable material (HWEM) water soluble alginate (WSA), alkali soluble alginate (ASA) and AASA in Hizikia fusiforme were 18.6, 4.7, 22.5 and 26.5%, respectively. The alginates manufactured by the WSA extraction method showed more bright color than those of the ASA and AASA extraction methods. The alginate prepared by the ASA extraction method from Hizikia fusiforme showed the higher viscosity than that of the ASA extraction method. The molecular weight of the alginate from Hizikia fusiforme was 33.3 kDa to 121.6 kDa depending on the extraction method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1285-1292
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• 2016

Changes in surface hydrophobicity of soy protein isolate (SPI), which plays an important role in the functional characteristics of protein, were measured according to various SPI concentrations, pH levels, electrolytes concentrations, and alginate molecular weights by using 1-anilino-8-naphthalene sulfonic acid as a fluorescent probe. SPI surface hydrophobicity decreased as SPI concentrations increased. SPI surface hydrophobicity reached a maximum at pH 7.0. SPI surface hydrophobicity rapidly increased as the NaCl concentration of SPI solution increased up to 100 mM, and showed no large increases above 100 mM. However, SPI surface hydrophobicity radically decreased until the $CaCl_2$ concentration reached 50 mM and revealed no large variations above 50 mM. A similar trend was exhibited in the case of $MgCl_2$. As both the concentration and molecular weight of sodium alginate increased, SPI surface hydrophobicity decreased. The increasing rate of SPI surface hydrophobicity decreased as the molecular weight of sodium alginate increased.