• Korean Journal of Microbiology
• /
• v.50 no.1
• /
• pp.73-83
• /
• 2014

The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.

• Journal of Conservation Science
• /
• v.24
• /
• pp.13-22
• /
• 2008

The identification of species, hygroscopic property, and ability of ethylene gas absorption of 23 ancient charcoals excavated from wooden coffin burials and roof-tile kilns of Chudong-ri cultural site were investigated. All of the 12 charcoals excavated from wooden coffin burials were broad-leaved trees. Among the total 12 samples, 9 samples were Lepidobalanus and others were Celtis spp.. On the other hand, other 11 charcoals from roof-tile kilns were needle-leaved tree, Pinus spp.(hard pine). The broad-leaved tree charcoals from wooden coffin burials showed a higher moisture absorption capacity than needle-leaved tree charcoals from roof-tile kilns. The ethylene gas absorption was greater in the Lepidobalanus charcoal than that of Celtis spp. and Pinus spp. (hard pine) charcoal. The broad-leaved tree charcoal having high absorption ability of substances was due to a large microporous and specific surface area. Therefore, it was estimated that broad-leaved tree charcoals were filled in order to make favorable condition in tomb. The wood quality of pine is soft and easy to burn because of low specific gravity, as well as high calorific value by resin in wood. We could assume that the pine wood was used as fuel for roof-tile kilns because of easy control of heating and thermal power.

• Korean Journal of Food Science and Technology
• /
• v.17 no.4
• /
• pp.253-257
• /
• 1985

Effects of four kinds of phosphate complex on the water holding capacity (W.H.C) and protein solubility of yellow-corvenia (Pseudosciance manchurica) and hair tail (Tichurus lepturus) meat paste were investigated. The formulations of four kinds of phosphate complex employed to this experiment were made by mixing several phosphates such as sodium polyphosphate, sodium pyro-phosphate, sodium acid pyro-phosphate, potassium pyro-phosphate, sodium tetra meta-phosphate, sodium ultra meta-phosphate and sodium hexa meta-phosphate, and monoglyceride at different mixture ratios. Among the four kinds of phosphate complex, phosphate B complex which was formulated by mixing sodium poly-phosphate 50%, sodium pyrophosphate 20%, sodium tetra meta-phosphate 20%, sodium acid pyrophosphate 5% and sodium ultra meta-phosphate 5% was most effective on enhancing the W.H.C and protein solubility of yellow corvenia meat paste, and in case of hair tail meat paste, phosphate C complex which was formulated by mining sodium poly-phosphate 40%, sodium pyro-phosphate 30%, potassium pyro-phosphate 15%, sodium tetra meta-phosphate 10%, and sodium hexa meta-phosphate 5% was more effective than other phosphate complex, and their optimum addition level was 0.4% respectively in weight of fish meat paste. Texture characteristics such as hardness, cohesiveness, and springiness value of Kamaboko (fish meat paste product) were evaluated as best when 0.3% of phosphate B complex was added. The optimum cooking condition of Kamaboko to get good texture was heating for 45 mimutes at $85^{\circ}C$.

• Journal of Biosystems Engineering
• /
• v.36 no.3
• /
• pp.217-222
• /
• 2011

This study was carried out in order to reduce the amount of underground water which is used in the double layered single span plastic greenhouse for retaining heat. For this research, two plastic green houses of the double layered single span plastic greenhouse were installed. There was equipped of internal small tunnel for keeping warm air in the interior of the house. Then the internal small tunnel for keeping warm air was fitted with PVC duct of 50 cm in diameter filled with subsurface water. The surplus solar energy in the greenhouse was stored in the water in the PVC duct. Four FCUs (Fan Coil Unit), which has the capacity of 8,000 kcal per hour, were installed in the middle of the house, and a circulation motor in heat storage water tank was operated from 10:30 a.m. to 16:00 p.m. in order to circulate water between the water tank and the FCUs. Consequently about 5 degrees celsius could be maintained in the interior of the internal small tunnel for keeping warm air with the external temperature of lower than minus 5 degrees celsius. It appeared that the alteration of an internal temperature of the house was flexible depending on the sunlight during daytime. To prevent the water freezing, mixing antifreezing liquid in the water or operating FCU continuously was needed. Also, in order to use the surplus solar thermal energy on plastic green house of water curtain system efficiently, storing the surplus heat during daytime simultaneously finding a method of using water curtain systematic underground water happened to be important. As a result of this research, when the house's interior temperature is below zero the operation of FCU appeared to be impossible. Considering the amount of water used in the house with water-curtain-heating system is 150~200 ton per day, using the system mentioned in this research showed that reducing the underground water more than 80% in order to maintain the internal temperature as the level of 5 degree celsius at the extreme temperature of minus 5 degrees celsius.

• The Korean Journal of Food And Nutrition
• /
• v.10 no.4
• /
• pp.544-548
• /
• 1997

Effects of four kinds of phosphate complex on the water holding capacity(W.H.C) and protein solubility of yellow-corvenia(Pseudosciance manchurica) and hair tail(Trichurus lepturns) meat paste were investigated. The formulations of four kinds of phosphate complex employed to this experiment were made by mixing several phosphates such as sodium polyphosphate, sodium pyro-phosphate, sodium acid pyro-phosphate, potassium pyro-phosphate, sodium tetra meta-phosphate, sodium ultra meta-phosphate and sodium hexa meta-phosphate, and monoglyceride at different mixture ratios. Among the four kinds of phosphate complex, phosphate B complex which was formulated by mixing sodium poly-phosphate 50%, sodium pyro-phosphate 20%, sodium tetra meta-phosphate 20%, sodium acid pyrophosphate 5% and sodium ultra meta-phosphate 5% was most effective on enhancing the W.H.C and protein solubility of yellow corvenia meat paste, and in case of hair tail meat paste, phosphate C complex which was formulated by mixing sodium poly-phosphate 40%, sodium pyro-phosphate 30%, potassium pyro-phosphate 15%, sodium tetra meta-phosphate 10%, and sodium hexa meta-phosphate 5% was more effective than other phosphate complex, and their optimum addition level was 0.4% respectively in weight of fish meat paste. Texture characteristics such as hardness, cohesiveness, and springiness value of Kamaboko(fish meat paste product) were evaluated as best when 0.3% of phosphate B complex was added. The optimum cooking condition of Kamaboko to get good texture was heating for 45 minutes at 85$^{\circ}C$.

• Clean Technology
• /
• v.13 no.2
• /
• pp.151-158
• /
• 2007

An experimental study to investigate the condensing heat transfer characteristics of small diameter horizontal double pipe heat exchangers with R-22 and R-410A was performed. Experimental facility was constructed to calculate and observe HTC(heat transfer coefficients), flow patterns and pressure drop. The main components include a liquid pump, an evaporator, a condenser(test section), a sight-glass, pressure taps and measurement apparatus. Two pipes of different diameters are tested; One 5.35 mm ID 0.5 mm thick, the other 3.36 mm ID 0.7 mm thick. The mass flow rate ranged from 200 to $500\;ks/m^2{\cdot}s$ and heating capacity were form 1.0 to 2.4 kW. The flow patterns of R-22 and R-410A were observed with a high speed camera through the sight-glass. The tests revealed that HTC of R-410A was higher than that of R-22 by maximum 5%. Annular pattern was observed for the most cases but stratified flow was also detected when x<0.2. The pressure drop in 3.36 mm ID pipe was higher than that of 5.35 mm by $30{\sim}50%$. Comparing with previous correlations such as Shah, Fujii and Soliman's, Fujii' showed the best good agreement with my data with a maximum deviation of 40%.

• Proceedings of the SAREK Conference
• /
• 2007.11a
• /
• pp.570-575
• /
• 2007

The thermal performance of the air receiver filled with porous material for 5kWt dish solar collector installed in Inha University, Korea, is experimentally investigated. The diameter of the parabolic dish is 3.2 m, and its focal length is 2 m. It consists of 10 small pieces of glasses which have their own curvatures, and the effective reflecting area is 5.9 m2. The reflectivity of the glass is 0.95, and the thermal capacity of the system is about 5 kW thermal. The aperture diameter of the cylindrical-shape receiver which is made of stainless steel is 100 mm, and the height is 210 mm. A quartz window is installed at the receiver aperture to minimize the convective heat loss and prevent air leakages. In order to increase the heat transfer area, porous material (nickel-alloy) is inserted into the receiver. Air flows into the upper part of the receiver, which is the opposite side of the aperture. After the air flows through the inside receiver, that goes out of the receiver through 3 exits which are located near the aperture. The volumetric flow rates of air are varied from 600 to 1200 L/min. The thermal efficiency of the receiver ranges from 82% - 92% depending upon the flow rate. The results show that the system efficiency and receiver efficiency increase as the volume flow rate increases as expected. These results from the experiment will be useful for the applications to air heating receivers and solar reactors.

• Plant Journal
• /
• v.10 no.2
• /
• pp.38-47
• /
• 2014

Renewable Portfolio Standards was introduced into the system in Korea in 2012. Interest in the unutilized and renewable energy sources is increasing. and these being actively investigated. An organic rankine cycle has emerged as an alternative in order to take advantage of bio-gas engine heat of sewage treatment plants whose capacity is 1500 kW. The organic rankine cycle power system was simulated by a simulator which is a commercial program of power plant design and performance analysis. The biogas engine is operated by $460^{\circ}C$ and 2.7 kg/s flow rate in the sewage treatment plant. Working fluids(R-601a, R-123, R-245fa) are selected to use in ORC power system in this temperature range. It was the isopentane that is the best performance among three working fluids. It could be obtained net power of 163.1 kW and efficiency of 13.66% from isopentane in the simulation.

• Korean Journal of Food Science and Technology
• /
• v.41 no.1
• /
• pp.16-20
• /
• 2009

To develop health functional foods using high amylose rice flours, the properties of flours prepared from domestic high amylose rice varieties, Goamy2 and Goamy, and imported rice from Thailand were investigated. After soaking the rice grains and drying, the dry-milled rice flours were passed through a 120-mesh sieve. The protein and total starch contents of the Goamy2 rice flour were lowest, but its crude lipid and ash contents were highest among the flours. In addition, apparent amylose content, water binding capacity, and total dietary fiber were highest in the Goamy2 flour (36.2, 255.0, and 9.2%, respectively). The Thai rice flour had the highest swelling power, whereas the Goamy2 flour had the lowest swelling power and solubility. By Rapid visco-analysis, the Thai flour showed the highest peak and total setback viscosities and lowest breakdown viscosity. The pasting pattern of the Goamy2 flour was different from that of the other flour, where low viscosity was maintained during heating and cooling. Goamy and Thai rice flours showed an A type crystallinity, but Goamy2 flour showed a B type crystallinity similar to high amylose maize starch. The Goamy2 flour presented a dull and yellowish color, and the lowest lightness (L) value and the highest yellowness (+b) value.

• Journal of Life Science
• /
• v.21 no.1
• /
• pp.56-61
• /
• 2011

This study was performed to investigate effective extract conditions in fronds of the Ostrich fern (Matteuccia struthiopteris) to increase antioxidant compound contents and antioxidant capacity. Powder (1 g) of lyophilizated fronds were mixed with 3 kinds of solvents (MeOH, 80% EtOH and water). Extractions were carried out using not only immersion (room temp.), heating ($60^{\circ}C$) and stirring (200rpm) for 6 hr, but also through sonication in a 42 kHz ultrasonic bath for 15, 30 and 45 min. Extracts were filtrated and measured for contents of soluble solids (SS), total polyphenols (TP; tannic acid as a standard) and total flavonoids (TF; Naringin as a standard). Antioxidant activity was expressed as $RC_{50}$ for DPPH and ABTS radical scavenging. SS (0.317 $g{\cdot}g^{-1}$ db), TP (70.90 $mg{\cdot}g^{-1}$ db) and TF (41.53 $mg{\cdot}g^{-1}$ db) contents reached their highest levels when 30 minute sonication extraction with 80% EtOH was performed, and the highest DPPH and ABTS scavenging activity was observed in the same extraction conditions ($RC_{50}$=0.14 $mg{\cdot}ml^{-1}$ and 0.09 $mg{\cdot}ml^{-1}$, respectively). From the present investigation, it can be concluded that fronds of the ostrich fern can be used as a natural material for antioxidants, and sonication for 15-30 min with 80% EtOH is an ideal extraction method for increasing their antioxidant effects and saving extraction time.