• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.317-319
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• 2002

Exo-polygalacturonase (EPG) from Rhizopus sp. was applied to the extraction of alginic acid from sea mustard to increase extraction yield. EPG digestion was examined under distinct conditions within temperatures from $25^{\circ}C$ to 5$0^{\circ}C$, pH 5 to 9, and treatment times from 0 to 36 hr. The optimal conditions fur alginic acid extraction with EPG were: pH 7.0 at 3$0^{\circ}C$ for 24 hrs. The EPG hot water extraction yield was 3.4 times higher yield than hot water extraction alone. Using EPG to extract alginic acid from sea mustard should be considered a viable alternative to conventional extraction, with the advantage of reducing hazardous wastes such as strong acid and alkali solutions.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.321-326
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• 2008

In order to improve the market competitiveness of the processed products of Undaria pinnatifida, various extraction conditions of Undaria pinnatifida were examined to determine the optimal conditions for the extraction of its valuable components. The highest level of alginic acid content was detected after 90 min of typical extraction or after 20 min of pressure extraction, after which the levels decreased slightly. The concentrations of reducing sugar and crude protein were also high after 90 min of typical extraction. Both alginic acid and reducing sugar were extracted in greater amounts using pressure extraction. The reducing sugar content was $2.8{\sim}3.2$ times higher using pressure extraction rather than typical extraction. Furthermore, the extraction results were superior with the, pressure extraction method. The appropriate temperature and duration of extraction were found to be $120^{\circ}C$ for 20 min. The use of a single enzyme yielded better results during extraction compared to the use of a mixture of enzymes. 20 min of pressure extraction followed by the addition of 0.1% pectinase and 2 hr of further extraction at $50^{\circ}C$ yielded high contents of alginic acid and reducing sugar from Undaria pinnatifida.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.336-340
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• 1984

The optimum conditions for extracting alginic acid from the powdered Undaria pinnatifida and amino acid composition of its extraction residue were investigated. Extraction with 60 volumes of 1.0% sodium carbonate solution to the sample at $80^{\circ}C$ gave a maximum yield of alginic acid and the optimum extraction time was 3 hours when all the other extraction conditions had teen satisfied. In the process of precipitating alginic acid gel from algin solution, the highest yield was obtained at pH 2.0 and 1.0% $H_{2}SO_{4}$ was more suitable than 10% HC1 as a precipitating agent. Extraction residue remained by separating algin solution contained 51.5% (on the dry baiss) of crude protein, and its limiting amino acid and protein score were lysine and 41.5, respectively.

• Korean Journal of Food Science and Technology
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• v.6 no.1
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• pp.36-41
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• 1974

Gracilaria verrucosa and Gelidium amansii collected from Wando, Yeosoo and Namhae districts Gracilaria sp. imported from Manila, and Ecklonia cava from Cheju island were investigated to raise the extraction yield of agar or alginic acid. The results are summarized as follows. In agar extraction from domestic seaweeds, Gelidium sp. showed 8-10% yield increase by gamma-irradiation whereas Gracilaria sp. exhibited no effect. In Manila seaweed, gamma-irradiation (1.5 Mrad) caused 25-30% increase in agar extraction and the properties of agar sample by these methods were acceptable. In alginic acid extraction from Ecklonia sp., gamma-irradiation (0.3 Mrad) showed 6% yield increase.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.336-341
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• 1982

The histochemical examination of Undaria pinnatifida Laver were conducted with light microscope and electron microscope. The results obtained were as follow: 1. Undaria pinnatifida frond were composed with epidermis, cortex and medulla. But the cutting section of Undaria pinnatifida Laver showed that only the epidermal cell were bound to each other. The cortex and medulla of the frond were destroyed during U.P. Laver process. 2. To identification of bind material of U.P. Laver, which were treated with sodium carbonate solution for extraction of alginic acid and reacted with Periodic Acid Schiff(PAS) reagent. And the PAS reaction result was negative by light microscope observation. On this result, we found out that the alginic acid has the binder role of U.P. Laver. 3. Also, the bind structure of U.P. Laver were observed by electron microscope and could well find out the epidermal cell wall and bind position of alginic acid, which were could not observed by light microscope.

• 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.

• 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.

• Journal of Food Hygiene and Safety
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• v.6 no.3
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• pp.165-169
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• 1991

The effect of gamma irradiation on physico-chemical properties of salted sea mustard (Undaria pinnatifida) was investigated. Chlorophyll and carotenoid pigment of salted sea mustard were partially decreased by irradiation. However there was no significant difference in the retention rate of pigment between control and 2 kGy-irradiated samples after six months of storage at around $10^{\circ}C$, ranging values of 74 to 77% in chlorophyll and 54 to 56% in carotenoid. Total organic acids and volatile acids associated with the organoleptic quality of sea mustard increased in the samples of lower salt concentrations and of higher storage temperatures. The softening of sample tissue by irradiation was shown to be correlated with the extraction properties of alginic acid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.779-783
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• 1999

The process of alginate preparation was shortened with microwave pretreatment and hot water extraction without any other treatment. The yield of extracted alginate was very different according to raw material and microwave treatment conditions. The yield of extracted alginate from sea mustard was higher than sea tangle and increased with the temperature rise and time of microwave treatment. Optimum extraction conditions by microwave treatment were 90 min at $100^{\circ}C$ for the sea mustard and 120 min at $100^{\circ}C$ for the sea tangle. On the other hand, the solubility of the alginate from sea mustard was $69\%\~80\%$ and the viscosity were 8.7$\~$1.5 cps, respectively. The solubility and the viscosity of the sea tangle alginate was higher than the sea mustard to $77\~84\%$ and in the range of 8.9$\~$1.8 cps, respectively. The extraction temperature by hot water greatly influenced on the yield of alginate, but the solubility and viscosity was not affected by the hot water extraction. The molecular weight of alginate obtained through the extraction by $Na_2CO_3$ solution and the microwave pretreatment was 800 kDa, and in the range of 12$\~$45 kDa, respectively.

• Food Science and Preservation
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• v.19 no.4
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• pp.525-531
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• 2012

This study was conducted to evaluate the quality and anti-oxidant characteristics of different granule tea variants (WSMGT: granule tea prepared from sea mustard hot water extract; ASMGT: granule tea prepared from sea mustard autoclave extract; WSTGT: granule tea prepared from sea tangle hot water extract; and ASTGT: granule tea prepared from sea tangle autoclave extract) from sea tangle and sea mustard powder. The Color of WSTGT showed the highest $L^*$, $b^*$ values, and the lowest $a^*$ value. The water absorption binding agents in ASMGT were higher than those in WSMGT, WSTGT. and ASTGT. Binding agents on water absorption in ASMGT were higher than those of WSMGT, WSTGT, and ASTGT. The alginic acid content of ASMGT was highest. The total polyphenol and total flavonoid contents of ASMGT and ASTGT were highest. The electron donating ability and ferrous ion chelating activity in WSTGT greatly increased compared to those in the other granules tea variants. These results suggest that pressure extraction can be used in functional foods.