• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.6
• /
• pp.343-349
• /
• 2007

This study examined the effective utilization of pearl processing by-products. Three extracts of hot-water extract (WE), hydro-cooked extract (HE), and two-step enzymatic hydrolysate (EH) were prepared from pearl oyster muscle, and their characteristics were examined. The moisture, crude protein, volatile basic nitrogen (VBN), and amino-N contents were 97.5-98.0%, 0.5-1.3%, 2.1-4.9 g/100 mL, and 35.0-74.5 g/100 mL, respectively. EH had the lowest VBN and highest amino-N contents. In addition, EH had the highest yields. In terms of its functional properties, EH inhibited angiotensin-I converting enzyme ($IC_{50}$, 1.39 mg/mL) more strongly than the other extracts ($IC_{50}$, 4.17-7.95 mg/mL). The free amino acid contents of WE, HE, and EH were 661, 470 and 1,150 mg/100 mL, respectively. Major amino acids were taurine and glutamic acid. Major inorganic ions were Na, Mg, and Ca. Contents of taste compounds, such as free amino acids, inorganic ions, and quaternary ammonium bases, differed significantly according to the extract methods. Based on the results of chemical experiments and sensory evaluation, the quality of EH was superior to the other extracts, and EH is suitable for use in natural flavoring materials.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.11
• /
• pp.1635-1641
• /
• 2008

This study investigated the effects of solid-state fermentation of a compound pig feed on its microbial and nutritional characteristics as well as on pig performance and nutrient digestibility. A mixed culture containing Lactobacillus fermentum, Saccharomyces cerevisae and Bacillus subtilis was used for solid-state fermentation and solid-state fermented feed samples were collected on days 0, 1, 2, 3, 5, 7, 10, 15, 20 and 30 for microbial counts and chemical analysis. Lactic acid bacteria increased rapidly during the first three days of fermentation and then slowly declined until day 10 and, thereafter, the counts were maintained at about 6.7 log cfu/g for the duration of the fermentation period. Enterobacteria also increased during the first two days, and then fell below the detectable level of the analysis (3.0 log cfu/g). The pH of the fermentation substrate declined from 6.1 at the start of fermentation to 5.7 by day 30. The water-soluble protein content increased from 8.2 to 9.2% while the concentration of acetic acid increased from 16.6 to 51.3 mmol/kg over the 30-day fermentation. At the end of the 30-day fermentation, the solid-state fermented feed was used in a pig feeding trial to determine its effects on performance and nutrient digestibility in growing-finishing pigs. Twenty crossbred barrows ($14.11{\pm}0.77kg\;BW$) were allotted into two dietary treatments, which comprised a regular dry diet containing antibiotics and a solid-state fermented feed based diet, free of antibiotics. There was no difference due to diet on pig performance or nutrient digestibility. In conclusion, solid-state fermentation resulted in high counts of lactic acid bacteria and low counts of enterobacteria in the substrate. Moreover, feeding a diet containing solid-state fermented feed, free of antibiotics, can result in similar performance and nutrient digestibility in growing-finishing pigs to a regular diet with antibiotics.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.774-779
• /
• 2006

The commercial green tea leaves were packaged with polyethylene film and irradiated by electron beam at doses of 0, 5, 10, 20, and 30 kGy. After irradiation, green teas were prepared by soaking the leaves in water (1 g/100 mL) at $75^{\circ}C$ for 10 min, and the physicochemical characteristics of green tea were determined. Electron beam irradiation decreased total phenol contents (TPC), total flavanol contents (TFC), ascorbic acid contents (AAC). Irradiation at dose of 20 kGy decreased TPC, TFC, and AAC from 223.46, 32.50, and 6.03 mg/g to 202.88, 31.16, and 5.57 mg/g, respectively, compared with non irradiated control. Electron beam irradiation also decreased catechins, caffeine, and nitrite scavenging activity of green tea. However, the changes of overall color and radical scavenging activity of irradiated green tea were negligible.

• Journal of Animal Science and Technology
• /
• v.54 no.1
• /
• pp.23-28
• /
• 2012

The effects of adding fish surimi to Gouda cheeses on quality characteristics during ripening were investigated. Cheese samples were prepared with 1.0% fish surimi, changes in chemical composition, lactic acid bacterial population, pH, non casein nitrogen, non protein nitrogen, water-soluble nitrogen, were monitored every 3 weeks during ripening. The electrophoresis patterns of cheese protein and the consumer's sensory evaluation test of Gouda cheese added with fish surimi also were analyzed. Slightly higher amounts of moisture, crude ash, crude protein, and crude fat were observed in the cheese supplemented with the fish surimi compared to the control cheese. The results suggested that the Gouda cheese prepared with fish surimi did not affect appearances or consumer's sensory characteristics of the cheeses.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.3
• /
• pp.276-281
• /
• 1985

This study was conducted to examine the morphological, physical and chemical characteristics of the Song-jeong (residuum), Dae-gog (local colluvium-alluvium), Ji-san and Og-cheon (local-alluvium) series with fine loamy texture derived from fine granitic parent materials on the drainage catena. 1. These soils consist of a catena, and then a color sequence due to the influence of topography, water table and free iron content. 2. The poorer the drainage, the higher were the silt/clay ratio, soil reaction, organic matter, and available phosphate content in soils but the active iron content was lower.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2012.05a
• /
• pp.88.1-88.1
• /
• 2012

Silicon nanowires (SiNWs), due to their unusual quantum-confinement effects that lead to superior electrical and optical properties compared to those of the bulk silicon, have been widely researched as a potential building block in a variety of novel electronic devices. The conventional means for the synthesis of SiNWs has been the vapor-liquid-solid method using chemical vapor deposition; however, this method is time consuming, environmentally unfriendly, and do not support vertical growth. As an alternate, the electroless etching method has been proposed, which uses metal catalysts contained in aqueous hydrofluoric acids (HF) for vertically etching the bulk silicon substrate. This new method can support large-area growth in a short time, and vertically aligned SiNWs with high aspect ratio can be readily synthesized with excellent reproducibility. Nonetheless, there still are rooms for improvement such as the poor surface characteristics that lead to degradation in electrical performance, and non-uniformity of the diameter and shapes of the synthesized SiNWs. Here, we report a facile method of SiNWs synthesis having uniform sizes, diameters, and shapes, which may be other than just cylindrical shapes using a modified nanosphere lithography technique. The diameters of the polystyrene nanospheres can be adjustable through varying the time of O2 plasma treatment, which serve as a mask template for metal deposition on a silicon substrate. After the removal of the nanospheres, SiNWs having the exact same shape as the mask are synthesized using wet etching technique in a solution of HF, hydrogen peroxide, and deionized water. Different electrical and optical characteristics were obtained according to the shapes and sizes of the SiNWs, which implies that they can serve specific purposes according to their types.

• Applied Chemistry for Engineering
• /
• v.19 no.5
• /
• pp.457-465
• /
• 2008

Development of various medical systems was accomplished through the progress of biotechnological method for therapy of human diseases. Furthermore, drug delivery systems have been investigated to carry the bioactive materials such as drug or gene in the body effectively. The most important thing in this system is to develop biomedical polymers having biocompatibility, biodegradability, and non-toxicity. Chitosan, a natural polymer, has been importantly considered as biomedical materials due to its good biocompatibility and various bio-active characteristics. Since the property of chitosan is differently explained according to the crystalline structures of chitin, the study for structural analysis of chitin has to proceed to apply as a biomaterial. From this point of view, this article introduced the analysis of crystalline structural of chitin, general property of chitosan and potential characteristics of low molecular weight water-soluble chitosan (LMWSC) as a biomaterials. Furthermore, chemical modification of LMWSC using various functional groups was also performed to enhance its bioavailability and emphasize their potential as drug delivery carriers (DDS).

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.23-23
• /
• 2018

In this study, new titanium alloys were prepared by adding elements such as tantalum (Ta), zirconium (Zr) and the like to complement the biological, chemical and mechanical properties of titanium alloys. The Ti-40Ta-xZr ternary alloy was formed on the basis of Ti-40Ta alloy with the contents of Zr in the contents of 0, 3, 7 and 15 wt. %. Plasma electrolytic oxidation (PEO), which combines high-voltage sparks and electrochemical oxidation, is a novel method to form ceramic coatings on light metals such as Ti and its alloys. These oxide film produced by the electrochemical surface treatment is a thick and uniform porous form. It is also composed of hydroxyapatite and calcium phosphate-based phases, so it has the characteristics of bone inorganic, non-toxic and very high bioactivity and biocompatibility. Ti-40Ta-xZr alloys were homogenized in an Ar atmosphere at $1050^{\circ}C$ for 1 hour and then quenched in ice water. The electrochemical oxide film was applied by using a power supply of 280 V for 3 minutes in 0.15 M calcium acetate monohydrate ($Ca(CH_3COO)_2{\cdot}H_2O$) and 0.02 M calcium glycerophosphate ($C_3H_7CaO_6P$) electrolyte. A small amount of 0.0075M zinc acetate and magnesium acetate were added to the electrolyte to enhance the bioactivity. The mechanical properties of the coated surface of Ti-40Ta-xZr alloys were evaluated by Vickers hardness, roughness test, and elastic modulus using nano-indentation, and the surface wettability was evaluated by measuring the contact angle of the coated surface. In addition, cell activation and differentiation were examined by cell culture of HEK 293 (Human embryonic kidney 293) cell proliferation. Surface properties of the alloys were analyzed by scanning electron microscopy(FE-SEM), EDS, and X-ray diffraction analysis (XRD).

• Food Science of Animal Resources
• /
• v.31 no.2
• /
• pp.232-240
• /
• 2011

The effects of adding fish surimi to Appenzeller cheese on quality characteristics during ripening were investigated. Cheese samples were prepared with 1.0% surimi. Changes in chemical composition, lactic acid bacterial population, pH, non-casein nitrogen, non-protein nitrogen, water-soluble nitrogen, a consumer sensory evaluation test, chromaticity, texture, and proteolysis were monitored during ripening. The electrophoretic patterns of cheese proteins and the functional components originating from the surimi were investigated. Adding surimi did not affect the appearance or consumer sensory characteristics of the cheeses. Significantly higher amounts of crude fat and moisture were observed in the cheese supplemented with surimi than in cheese without added surimi.

• Journal of Animal Environmental Science
• /
• v.7 no.3
• /
• pp.169-172
• /
• 2001

This research was carried out to investigate the quantity of Holstein milking cow manure excreted and their characteristics. The average body weight of the Holstein milking cow during experiment was 550.0kg, and fried intake(DM basis), water consumption, milk yield was 16.7, 85.4, 24.4k7/day/head, repectively. The average manure production of Holstein milking cow was 63.5kg/day/head(feces 42.3, urine 10.2kg). The average moisture content of feces and urine was 83.9%, 96.9%, respectively. Wastewater pollutant concentration of $BOD_5$(Biochemical Oxygen demand). $COD_{Mn}$ (Chemical Oxygen demand), SS(Suspended Solids), T-N(Total Nitrogen) and T-P(Total Phosphorus), excreted from Holstein milking cow was 16,560, 40,329, 78,500, 2,854, 577mg/ l in feces and 4,580, 7,575, 370, 4,164, 7mg/ l in urine, repectively.