• Applied Biological Chemistry
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• v.15 no.1
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• pp.19-25
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• 1972

A kind of peptide which posseses an yeaststatic activity was isolated from Astragalus membranaceus Bunge and following characteristics was obtained. 1. The isoelectric pH of this peptide was 8.2 and histidine, an alkaline amino acid, was identified from this peptide. 2. This substance showes conspicuous heat stability and does not indicate any remarkable reduction of yeaststatic activity even for 5 hours treatment at $100^{\circ}C$. or for 30 minutes at $121^{\circ}C$. 3. The inhibitory activity of the yeast growth is not originated from the yeastcidal action but yeaststatic effect of this sample. 4. The sample shows strong stability ranging from pH 2 to 10. 5. The saccharide; glucose, sucrose, maltose, gives no effect on the yeaststatic activity of the sample even high concentration, 15 percent, and also no effect gives by magnesium, calcium and phosphate salts. 6. The available concentration of this sample on the inhibition of yeast growth was located at the ppm extent, for example, the concentration of fifty percent growth inhibition to Saccharomyces cerevisiae or S. carsbergensis was 4 ppm and 3 ppm to Candida pulcherrima, 13 ppm to S. coreanus, 18 ppm to S. sake and 38 ppm to C. tropicalis. 7. On the alcohol fermentation of S. coreanus, the peptide, an yeast growth inhibitor, gives no effect at all. 8. This substance is named as Astradix-P (Astragalus membranaceus, Radix, Peptide).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.436-445
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• 1986

As the second part of the studies on the utilization of polyunsaturated lipids in sardine oil as nutritional or medical supplement, the conditions of lipid extration and concentration, refining, and storage stability of EPA-condensed sardine oil were investigated. In extraction of lipids, solvent ratios of chloroform-methanol mixture(2:1 v/v) affected the final content of unsaturated lipid in extracted oil and recovery. Stepwise solvent fractionation method at various low temperatures was effective to concentrate polyenoic acids like EPA and DHA when acetone or acetone-methanol mixture, added in the ratio of 1:5 (v/v) was applied step by step to different temperatures at 0 to $-35^{\circ}C$. Addition of 1 to $5\%$ (v/v) of water to acetone was also benefit to raise EPA content but that resulted in reducing the yield of condensed oil from $65\%\;to\;28\%$. Concentration rate of polyenoic acids by solvent fractionation in lipid-actone solution (1:5, v/v) at 0 to $-30^{\circ}C$ seemed limited to $5{\sim}8\%$ in fatty acid composition depending on the initial content of those polyenoic acids in the sardine oil. During the extraction, concentration, and alkaline treatment, oxidation was rapidly induced but oxidation products could be thoroughly removed on the process of deceleration and peroxide elimination. To stabilize the reactive polyenoic acid condensed oil during the storage, stuffing nitrogen gas was essential to expel dissolved oxygen in oil or to seal the oil from open air, and the addition of antioxidative agents as BHA and tocopherols were greatly helpful to extend the storage life.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.320-326
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• 2001

To obtain the basic data for preparing edible or biodegradable film, fish meal protein isolates (FMPI) were prepared through alkaline extraction. And FMPI's properties and the ester compounds permeability of FMPI film were measured. FMPI were extracted under various extracting time with 0.2 N NaOH solution at $60^{\circ}C$, Recovery ratios of FMPI extracted from fish meal were increased with extracting time increasing. Surface hydrophobicity of FMPI extracted for 1 hr showed highest value. Emulsifying activity index (EAI) was increased with the increasement of extracting time but its emulsifying stability index (ESI) showed an inverse results. Viscosity of FMPI solution showed the highest value at pH 2 but showed the lowest value at pH 4, The higher concentration of sorbitol as plasticizer showed the higher ethyl acetate permeability of FMPI film, Ethyl acetate permeability of FMPI films according to kind of plasticizers showed different degree and increased in order as follow: polyethylene glycol, glycerol and sorbitol. Ester compounds having the lower molecular weight showed the higher permeability. Increment of temperature increased the ethyl acetate permeability of FMPI film. FMPI haying higher surface hydrophobicity made FMPI film be higher tensile strength. On elongation of FMPI films, kinds of plasticizer were more effective than surface hydrophobicity of FMPI.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.119-135
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• 2013

This study investigates waxy barley powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15% and 20%. Waxy barley powder consisted of 8.33% of moisture content, 10.47% of crude protein, 1.63% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the waxy barley powder content increased. The farinograph measurement result of the bread made with waxy barley powder showed that consistency, water absorption, development time, stability and time breakdown have increased as the waxy barley powder content increased. The amylograph measurement result of the bread made with waxy barley powder showed that T have increased as the waxy barley powder content increased. Their P, H and P-H have decreased as the ingredient contents increased. Baking loss and specific loaf volume have decreased as the waxy barley powder content increased. The chromaticity measurement result of the bread made with waxy barley powder showed no significant difference as the waxy barley powder content increased. The texture measurement result showed that the hardness and gumminess of bread have increased as the waxy barley powder content increased. Their cohesiveness, springiness and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high acceptability for the bread made with 10% waxy barley powder.

• Journal of Conservation Science
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• v.26 no.4
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• pp.397-406
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• 2010

The most ideal method to measure the water-soluble $Cl^-$ ion eluted from iron artifacts is conducting the analysis on desalting solution by Ion Chromatography. But most institutes related to cultural heritages use Cl meter by reason of lack of budget and experts. This study evaluated reliability and stability between Cl meter and Ion Chromatography by doing cross-validation with results from two methods to detect $Cl^-$ ion of desalting solution. From D.I water, extremely small quantities of $Cl^-$ ion was detected by the influence of remaining water-soluble $Cl^-$ ion at the electrode of Cl meter and water-soluble $Cl^-$ which remains in Sodium sesquicarbonate, components of reagent was detected as well. The first desalting solution had the most $Cl^-$ ions, $Cl^-$ ion slightly decreased from the second to the fourth desalting solution and tend to decrease again at the stage of dealkalified in D.I water. Each Cl meter has the standard deviation according to the measured numbers and the higher concentration of $Cl^-$ ion the desalting solution has, the wider the deviation is. But when the concentration of $Cl^-$ ion is low, it was stable to use Cl meter to detect the concentration of $Cl^-$ ion from iron artifacts because there is the small deviation, It is thought that conductivity meter method is not suitable for measuring $Cl^-$ ion, because the electrical conductivity of alkaline solution is too high to measure $Cl^-$ ion.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.469-476
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• 1986

Proteolytic activity of the tissue extracts from the muscle of mackerel, Scomber japonicus, and sardine, Sardinops melanostcta, was comparence with referenced to the optimum reaction condition. Thermal stability and change of proteolytic activity of the tissue extracts during storage were investigated. The existence of acid, weak acid and alkaline proteinase was identified in the ordinary and dark muscle of the mackerel and sardine. Specific activity of acid proteinase was stronger than weak acid or alkaline proteinase in the both fish. The proteolytic activity of the tissue extracts on the optimum reaction condition was: ordinary muscle of mackerel, 0.12 nM-Tyr. eq./mg-prot. /min. at pH 3.0 and $50^{\circ}C$; dark muscle of mackerel, 0.36 nM-Tyr. eq./mg-prot. /min. at pH 3.0 and $45^{\circ}C$; ordinary muscle of sardine, 0.45 nM-Tyr. eq./mg-prot. /min. at pH 2.4 and $45^{\circ}C$; dark muscle of sardine, 0.24 nM-Tyr. eq./mg-port. /min. at pH 2.4 and $45^{\circ}C$. The proteinases distributed in the muscle of mackerel and sardine were stable with the heat treatment at $45^{\circ}C$ for 5 minutes, but those in the dark muscle of mackerel was stable with the treatment at $5^{\circ}C$ for 5 minutes. The proteinases from the muscle were slowly inactivated with the whole storage days at $5^{\circ}C\;and\;-15^{\circ}C$, those were more stable at $-15^{\circ}C\;than\;5^{\circ}C$ storage.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.112-118
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• 2012

Steel industry produces many by-products and wastes such as blast furnace slag, electric arc furnace slag, and converter slag. As in the case of rock, the main component of steel slag are CaO and $SiO_2$ ; further, steel slag is as alkaline as portland cement or concrete. Electric arc furnace oxidizing slag is possible to use as an aggregate for concrete ; however, it has been reclaimed because of it's expansibility caused by free CaO. Recently, a innovative rapid cooling method for melting steel slag has been developed in Korea, which reduces free lime content to minimum level and increases the stability of iron oxide. Therefore, this study describes the results of a series of research to utilize globular shape of electric arc furnace oxidizing slag fine aggregates made by rapidly cooled method for the construction industry by cooling rapidly melted slag from the steel industry. First of all, an experiment was carried out to investigate the quality characteristics of rapidly cooled electric arc furnace oxidizing slag fine aggregates in order to determine whether they can be applied to the construction industry. Then, by applying them to concrete of various particle sizes, we explored experimentally the desired condition to apply rapidly cooled electric arc furnace oxidizing slag fine aggregates to concrete.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.5
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• pp.341-345
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• 2010

Introduction: Skeletal homeostasis is normally maintained by the stability between bone formation by osteoblasts and bone resorption by osteoclasts. However, the correlation between the inflammatory reaction and osteoblastic differentiation of cultured osteoprogenitor cells has not been fully investigated. This study examined the effects of inflammatory cytokines on the osteoblastic differentiation of cultured human periosteal-derived cells. Materials and Methods: Periosteal-derived cells were obtained from the mandibular periosteum and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured in an osteogenic induction Dulbecco's modified Eagle's medium (DMEM) medium containing dexamethasone, ascorbic acid, and $\beta$-glycerophosphate. In this culture medium, tumor necrosis factor (TNF)-$\alpha$ with different concentrations (0.1, 1, and 10 ng/mL) or interleukin (IL)-$1{\beta}$ with different concentrations (0.01, 0.1, and 1 ng/mL) were added. Results: Both TNF-$\alpha$ and IL-$1{\beta}$ stimulated alkaline phosphatase (ALP) expression in the periosteal-derived cells. TNF-$\alpha$ and IL-$1{\beta}$ increased the level of ALP expression in a dose-dependent manner. Both TNF-$\alpha$ and IL-$1{\beta}$ also increased the level of alizarin red S staining in a dose-dependent manner during osteoblastic differentiation of cultured human periosteal-derived cells. Conclusion: These results suggest that inflammatory cytokines TNF-$\alpha$ and IL-$1{\beta}$ can stimulate the osteoblastic activity of cultured human periosteal-derived cells.

• KSBB Journal
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• v.15 no.4
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• pp.352-358
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• 2000

Preparation for the simplified separation of chitosandoligosaccharides from enzymatic hydrolysate was investigated. Two different types of chitosan beads as substrate were prepared as organic-based bead by W/O emulsion method and water-based bead by alkaline treatement. The average size of organic-based bead was $200{\mu}m$, and that of water based beads were $4000{\mu}m$, $100{\mu}m$, $30{\mu}m$, in diameter respectively. Enzyme stability was maintained over 80% at PH 6 after 24 hours. The optimal condition for the production of chitosanoligosaccharides was at pH 6.0, $50^{\circ}C$ and 40U (200U/g-chitosan) According to final oligosaccharide concentration water-based bed showed the similar result with that of organic-based bead even through it had smaller surface area attacked by chitosanse than that of organic-based bead. It is probable that the structure of water-based chitosan bead was looser than that of organic-based bead so enzyme penetrated easily into the bead structure. For the oligosaccharide production versus surface area the different size of water-based beads was investigated, Maxiaml production yield was observed in the $30{\mu}m$ beads. Consequently the water-based chitosan bead was better than the organic-based bead in this reaction system.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.504-511
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• 2016

Lactulose, a synthetic disaccharide, has received increasing interest because of its role as a prebiotic that can increase the proliferation of Bifidobacterium and Lactobacillus spp. and enhance the absorption of calcium and magnesium. While the industrial production of lactulose is still mainly achieved by the chemical isomerization of lactose in alkaline media, this process has drawbacks including the need to remove catalysts and by-products, as well as high energy requirements. Recently, the use of cellobiose 2-epimerase (CE) has been considered an interesting alternative for industrial lactulose production. In this study, to develop a process for enzymatic lactulose production using CE, we screened improved mutant enzymes ($CS-H^RC^E$) from a library generated by an error-prone PCR technique. The thermostability of one mutant was enhanced, conferring stability up to $75^{\circ}C$, and its lactulose conversion yield was increased by 1.3-fold compared with that of wild-type CE. Using a recombinant Escherichia coli strain harboring a CS35 $H^RC^E$-expressing plasmid, we prepared cell beads immobilized on a Ca-alginate substrate and optimized their reaction conditions. In a batch reaction with 200 g/l lactose solution and the immobilized cell beads, lactose was converted into lactulose with a conversion yield of 43% in 2 h. In a repeated 38-plex batch reaction, the immobilized cell beads were relatively stable, and 80% of the original enzyme activity was retained after 4 cycles. In conclusion, we developed a reasonable method for lactulose production by immobilizing cells expressing thermostable CE. Further development is required to apply this approach at an industrial scale.