• Journal of Life Science
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• 제9권1호
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• pp.45-49
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• 1999

Seaweed alginate was acetylated by activated carbon immobilized Pseudomonas syringae in a fluidized bed, up-flow reactor. The acetylation degree of seaweed alginate was about 30%. Calcium-acetylated seaweed alginate gel bead was made and compared to calcium-seaweed alginate gel bead by the scanning electron microscopy (SEM). Structural difference of two gel beads may results from increased viscosity and decreased affinity of acetylated seaweed alginate for calcium ion. On the basis of interior and exterior structure of calcium-acetylated seaweed alginate gels and property of acetylated seaweed alginate, it seems that acetylated seaweed alginate is used for the supporter for electrophoresis and packing materials for liquid chromatography and gel filtration.

• Food Science and Biotechnology
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• 제16권5호
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• pp.715-721
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• 2007

In this study, the sphericity of calcium alginate gel beads was optimized using response surface methodology. The optimum conditions for bead sphericity were a concentration of 2.24% sodium alginate, a flow rate of 0.059 mL/sec for the sodium alginate solution, and a 459 rpm rotation for the calcium chloride solution. The predicted and experimental bead sphericities under the optimum conditions were 94.5 and 96.7%, respectively, showing close agreement. We also investigated the processing condition effects for the physical properties of the optimized calcium alginate gel beads. Immersion in hot water slightly decreased bead size and rupture strength. NaCl treatment increased bead size and decreased rupture strength. While the pH of the calcium chloride solution had little effect on bead sphericity, the bead sizes and gel strengths decreased with longer times in each pH solution. The beads coated with pectin and glucomannan showed no significant changes in sphericity, but their sizes decreased with time. The coated beads showed higher rupture strengths than the uncoated beads.

• 한국토양비료학회지
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• 제47권5호
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• pp.351-355
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• 2014

In recent years, biochar has received much attention as soil amendment, enhancing soil fertility and reducing toxicity of heavy metals with its large specific surface area and high pH. Biochar has also the effect of alleviating global warming by carbon sequestration from recycling organic wastes by pyrolysis. However, scattering of fine particles of biochar is a hindrance to expand its use from human health point-of-view. Alginate, a natural polymer without toxicity, has been used for capsulation and hydrogel fabrication due to its cross-linking nature with calcium ion. In this study, the method of cross-linkage between alginate and calcium ion was employed for making dust-free biochar bead. Then an equilibrium adsorption experiment was performed for verifying the adsorption effect of biochar bead on heavy metals (cadmium, copper, lead, arsenic, and zinc). Results showed that biochar bead had effects on adsorbing heavy metals, especially lead, except arsenic.

• Journal of Pharmaceutical Investigation
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• 제25권2호
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• pp.153-161
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• 1995

Alginic acid is a hydrophilic , colloidal polysaccharide obtained from cell wall of seaweed or brown algae and has a broad range of applications. Alginlc acid becomes alginate gel bead due to its cation-induced gelation. Dried alginate beads can be reswollen according to environmental pH. The purpose of this paper is to explore the possible applicability of alginate beads as an oral controlled release system of ibuprofen. In this experiment ibuprofen was incorporated in alginate beads and alginate beads were treated with various methods. Ibuprofen release from alginate beads in phosphate buffer (pH 7.4) was laster than in distilled water and dilute HCl. The release of ibuprofen was more sustained in bead than simple mixture and coprecipitate of ibuprofen and sodium alginate. The dissolution rate of ibuprofen was decreased in using of bead that hardened with formaldehyde. The dissolution rate of the drug from the bead was the fastest in 12 hour dried beads, 1.5%-sodium alginate concentration and 1%-calcium chloride concentration. Sodium alginate bead can be used as a sustaind release drug delivery system of water-insoluble drugs.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.431-433
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• 2011

Alginate microfibers were fabricated by self assembly of alginate monomers exuded from alginate beads (~2 mm in diameter) containing calcium phosphate. Upon incubation of the beads in cell culture medium at $37^{\circ}C$ for a few days, fibers with a diameter of about $7{\mu}m$ started to sprout from the bead surface, and these grew up to about 10 mm in length, resulting in the beads being covered with fiber forests similar to chestnut bur. The combined system of the alginatebased microfiber forest and bead is considered to be useful as a novel 3-dimensional scaffold for cell culture and tisssue growth.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.412-417
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• 2001

Sodium alginate was used to immobilize Bifidobacterium breve ATCC 15700 cells. The ability of the Ca-alginate beads to protect the B. breve ATCC 15700 was evaluated under different conditions including alginate concentration, bead size, pH, hydrogen peroxide, and storage period. The survival of the B. Breve ATCC 15700 was estimated in pasteurized yogurt, containing either the immobilized or free cells, throughout the storage period. The survival cells in bead after exposure to acidic solution (pH 3.0) increased with increase of both the alginate gel concentration and bead size. Also, immobilized cells in alginate bead were more resistant than the free cells to hydrogen peroxide, storage period, and the environment inside yogur. When retreated beads with skim milk and nonretreated beads were tested in acidified pH 3.0 TPY media including acetic and lactic acid, the number of viable cells in the retreated bead was approximately 10-fold higher than that of nonretreated beads. This suggests that the skim milk operated as a material decreasing the diffusion of acid and hydrogen perosicde into alginate gels. From this research, it was found that yogurt itself supported immobilized cells with an improved protection from the extreme acidity in yogurt.

• 산업식품공학
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• 제14권3호
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• pp.208-216
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• 2010

유산균을 고농도로 배양하기 위하여 $CaCO_3$를 각각 15% 와 20%씩 첨가하여 직경이 서로 다른 $CaCO_3$-alginate beads를 제조한 후, lactic acid에 대한 $CaCO_3$-alginate beads의 반응 특성과 완충효과를 관찰하였으며, lactic acid에 대하여 완충작용이 있는 $CaCO_3$-alginate beads를 이용하여 S. thermophilus ST-Body 1과 L. amylovorus DU-21을 고농도 배양하여 직접투입식 starter를 제조하였다. 본 연구에서 제조된 $CaCO_3$-alginate beads는 $CaCO_3$, alginate 함량 및 수분 함유율이 beads에 일정하게 고루 분포되어 있으며, 일정한 밀도를 갖는 입자임을 알 수 있었다. 또한 lactic acid에 대한 beads의 반응은 표면으로부터 일어나기 시작하여 내부로 진행됨을 확인하였으며, $CaCO_3$-alginate beads 양의 증가는 결국 lactic acid와 반응할 수 있는 $CaCO_3$ 표면적의 증가를 가져오게 되며, 단위시간당 lactic acid와 반응하는 $CaCO_3$의 상대적 증가를 가져오기 때문에 $CaCO_3$-alginate beads 양의 증가는 lactic acid 용액 내부의 중화작용의 증가를 가져온다는 것을 확인하였다. 즉, $CaCO_3$-alginate beads의 직경이 작을수록, 내부의 $CaCO_3$ 함량이 높을수록, 단위 부피당 넓은 표면적과 높은 중화작용을 가지므로 $CaCO_3$-alginate beads를 pH neutralizer로 이용하여 유산균을 배양할 경우에는 $CaCO_3$ 함량이 높고 직경이 작은 $CaCO_3$-alginate beads의 이용이 유산균 배양에 효과적임을 알 수 있었다. $CaCO_3$-alginate beads를 이용한 유산균의 고농도 배양시, pH와 생균수와의 상관성과 선형관계를 단순회귀분석법(simple regression)을 이용하여 최소자승추정량(least square estimator; LSE)을 구하여 검증한 결과, 각 X의 회귀계수의 값은 통계적으로 유의한 결과(p<0.05, p<0.01)를 보였다. 또한 $R^2$ 값은 S. thermophilus ST-Body 1와 L. amylovorus DU-21의 경우, $CaCO_3$-alginate beads 무첨가구와 첨가구에서 각각 0.6310, 0.7505, 0.7452, 0.7609이였다. 이는 pH가 균 증식에 다소나마 영향을 주는 것을 나타낸다. 고농도로 배양된 S. thermophilus ST-Body 1과 L. amylovorus DU-21 균주를 이용하여 직접투입식 starter를 제조한 결과, 동결건조 보호제로 15% glycerol을 이용하였을 때 각각 91.96${\pm}$1.35%와 89.09${\pm}$4.49%의 생존율을 보였다. 본 연구에서 확립된 기법은 probiotics 조제나 정장제 조제방법에 있어서도 공히 적용 가능하므로 미생물 세포의 이용기법으로 그 생존율과 발효에 연관되는 기능보존과 수반되는 여러 분야에 적용한다는 면에서 산업적으로 중요하다고 사료된다.

• Korea-Australia Rheology Journal
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• 제19권3호
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• pp.157-164
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• 2007

Microencapsulation of cells within microfluidic devices enables explicit control of the membrane thickness or cell density, resulting in improved viability of the transplanted cells within an aggressive immune system. In this study, living cells (3T3 and L929 fibroblast cells) are encapsulated within a semi-permeable membrane (calcium crosslinked alginate gel) in two different device designs, a flow focusing and a core-annular flow focusing geometry. These two device designs produce a bead and a long microfibre, respectively. For the alginate bead, an alginate aqueous solution incorporating cells flows through a flow focusing channel and an alginate droplet is formed from the balance of interfacial forces and viscous drag forces resulting from the continuous (oil) phase flowing past the alginate solution. It immediately reacts with an adjacent $CaCl_2$ drop that is extruded into the main flow channel by another flow focusing channel downstream of the site of alginate drop creation. Depending on the flow conditions, monodisperse microbeads of sizes ranging from $50-200\;{\mu}m$ can be produced. In the case of the microfibre, the alginate solution with cells is extruded into a continuous phase of $CaCl_2$ solution. The diameter of alginate fibres produced via this technique can be tightly controlled by changing both flow rates. Cell viability in both forms of alginate encapsulant was confirmed by a LIVE/DEAD cell assay for periods of up to 24 hours post encapsulation.

• Applied Biological Chemistry
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• 제44권3호
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• pp.185-190
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• 2001

알긴산은 일반적으로 미생물의 고정화에 널리 사용되는 biopolymer이다. 본 연구는 구연산 생산균인 Aspergillus niger를 calcium alginate로 고정화한 beads로 납의 흡착 특성을 조사하였다. A. niger beads는 $CaCl_2$를 사용하여 주사기로 제조하였으며 이 beads를 납제거에 이용하였다. 그 결과는 다음과 같다. 즉, A. niger를 구연산 생성배지에서 1일에서 7일까지 배양한 후 제조한 beads로 납흡착량을 측정한 결과는 3일간 배양된 곰팡이 beads에서 가장 높았다. 발아되지 않은 beads와 3일간 배양된 beads로 시간에 따른 납흡착량을 정량한 결과 30분까지는 그 흡착량이 동일하게 급격히 증가하였으며 그 후 발아되지 않은 beads는 더 이상 흡착이 일어나지 않았으나 3일간 배양된 곰팡이 beads는 시간이 지남에 따라 천천히 계속 흡착하여 1시간 후에는 480 ppm까지 흡착하였다. 납흡착시 최적 pH와 온도는 각각 6과 $35^{\circ}C$로 나타났다. 납용액 50 ml (500 ppm)이 든 250 ml 삼각플라스크에 beads $50{\sim}100$개가 최적이었으며 그 이상에서는 납흡착율이 감소하였다. 중금속에 대한 흡착율은 납> 구리> 카드뮴 순이었으며 0.1 M $CaCl_2$, 0.1 M NaOH 및 0.1 M KOH의 전처리의 효과는 없었으며 0.1 HCI로 곰팡이 bead의 납탈착하여 beads를 재사용이 가능하였다.

• 한국식품조리과학회지
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• 제27권5호
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• pp.497-505
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• 2011

The purpose of this study was to apply molecular gastronomy and spherification methodology to persimmon deserts. We prepared 'persimmon calcium alginate beads' and investigated their physical and sensory characteristics by adding different concentrations of sodium alginate (0.4, 0.6, 0.8, and 1.0%). Lightness and yellowness decreased significantly as the concentration of sodium alginate increased. However hardness, springiness, chewiness, cohesiveness, and resilience but not adhesiveness tended to increase as the concentration of sodium alginate increased. The thickness of the beads increased as the concentration of sodium alginate increased. In contrast, the thickness of the membrane decreased as the concentration of alginate increased from 0.8 to 1.0% suggesting that the amount of sodium alginate had reached a critical point. Quantitative descriptive analysis showed that voluminosity, springiness, hardness, chewiness, and residue tended to increase as the concentration of sodium alginate increased. Overall preference reached a peak at 0.4% sodium alginate.