• Food Science of Animal Resources
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• v.26 no.4
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• pp.471-477
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• 2006

This study was conducted to evaluate the application of high dose irradiation for ensuring shelf stability of marinated and precooked pork rib steak in the severe environments such as desert or space, etc. Marinated and precooked pork rib steak was manufactured, vacuum-packaged and gamma-irradiated with the absorbed doses of 10, 20, 30, 40 and 50 kGy, and used for the tests of the growth of microorganisms and lipid oxidation during storage at 35t of acceleration condition. Any growth of microorganisms was not observed in irradiated samples after irradiation immediately. However, the growths were observed in 10, 20 and 30 kGy samples at 4, 7 and 14 day storage, respectively. High dose (40 and 50 kGy) gamma irradiation retarded the growth of aerobic microorganisms by the analysis of kinetic parameter. The content of malondialdehyde increased in all samples during storage periods, and gamma irradiation accelerated the increase of lipid oxidation. Therefore, the application of combination of the various food processing technology should be considered for the sterilization of marinated and precooked pork rib steak without any deterioration of the quality occurred by high dose irradiation.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.97-102
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• 2010

Curcuminoids are polyphenolic compounds and include curcumin and its derivatives possessing a yellow color. In the present study, changes in the chemical stability and antioxidant activities of curcuminoids, including curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BMC), were investigated under various processing conditions. The yellowness of a mixture of the curcuminoids (79.4% curcumin, 16.8% DMC, and 3.8% BMC) at 405 nm was proportional to their amounts analyzed by HPLC. The curcuminoids became less stable with increases of pH and temperature during storage. Exposing a solution of the curcuminoids to autoclave conditions ($121^{\circ}C$, 1.2 atm for 15 min) decreased residual curcuminoid levels by 80-90%; however, as a powder under the same conditions the curcuminoids were much more stable with less than 10% loss. After autoclave treatment, scavenging activities of the curcuminoids for DPPH and ABTS radicals were reduced by 10.3 and 33.4%, respectively, whereas nitric oxide scavenging activity was slightly increased. The residual levels of curcumin, DMC, and BMC after autoclaving were 0.7, 1.4, and 0.9%, respectively, indicating that curcumin was the most sensitive to autoclave treatment. The results indicate that under processing conditions, pH and temperature markedly affect the stability of curcuminoids and major losses of curcuminoids occur after autoclaving. These conditions should be considered when processing foods containing curcuminoids.

• Journal of dental hygiene science
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• v.18 no.2
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• pp.69-75
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• 2018

The purpose of our study is to compare the adhesion and biofilm formation abilities of isolates from water discharged from dental unit waterlines (DUWLs). Bacteria were isolated from a total of 15 DUWLs. Twelve isolates were selected for the experiment. To confirm the adhesion ability of the isolates, each isolate was attached to a glass coverslip using a 12-well plate. Plates were incubated at $26^{\circ}C$ for 7 days, and the degree of adhesion of each isolate was scored. To verify the biofilm formation ability of each isolate, biofilms were allowed to form on a 96-well polystyrene flat-bottom microtiter plate. The biofilm accumulations of all isolates formed at $26^{\circ}C$ for 7 days were identified and compared. A total of 56 strains were isolated from 15 water samples including 12 genera and 31 species. Of the 56 isolates, 12 isolates were selected according to the genus and used in the experiment. Sphingomonas echinoides, Methylobacterium aquaticum, and Cupriavidus pauculus had the highest adhesion ability scores of +3 among 12 isolates. Among these three isolates, the biofilm accumulation of C. pauculus was the highest and that of S. echinoides was the third-most abundant. The lowest biofilm accumulations were identified in Microbacterium testaceum and M. aquaticum. Most isolates with high adhesion ability also exhibited high biofilm formation ability. Analysis of adhesion and biofilm formation of the isolates from DUWLs can provide useful information to understand the mechanism of DUWL biofilm formation and development.

• Korean Journal of Microbiology
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• v.46 no.3
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• pp.270-277
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• 2010

In order to manufacture Bacillus cereus-free fermented soybean products, an antimicrobial agentproducing isolate against B. cereus was obtained from 150 traditionally fermented soybean products. The morphological and biochemical tests and the phylogenetic relationship among 16S rRNA gene sequences indicated that the isolate named as the strain SCK 121057 was most closely related to Bacillus licheniformis. The B. licheniformis isolate began to produce the antimicrobial agent after 48 h of incubation. The agent was nonproteinaceous and insensitive to heat, long term storage and protease K. Electron microscopic observation indicated that the agent attacked the membrane of B. cereus, leaving the ghost cell. The isolate inhibited growth of B. subtilis, Lactobacillus brevis and various types of pathogenic strains including Escherichia coli, E. faecalis, Micrococcus luteus, Staphylococcus aureus, Aspergillus flavus, A. ochraceus, and A. parasiticus as well as B. cereus. After coinoculation of B. licheniformis SCK 121057 and B. cereus in the ratio (as the basis of CFU/g sample) of 10 to 1 on the surface of cooked soybeans, cell numbers of B. cereus had been dramatically reduced after 31 days of incubation compared to those of single inoculation of B. cereus.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.974-981
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• 1997

A combined treatment of high hydrostatic pressure and carbonation was used to inactivate pectinesterase (PE) and sterilize microorganisms in Valencia orange juice without major changes in its nutritive components. Quality characteristics of Valencia orange juice, such as microorganisms, PE activity, vitamin C content and color, were evaluated after it was treated with pressure, carbonation-and-pressure, and heat. Quality changes during storage at $4^{\circ}C$ and $30^{\circ}C$ after the treatments were also investigated. Pressurized orange juice (pressurized at 600 MPa for 10 min at $20^{\circ}C$) showed 7.0% residual PE activity, while the carbonated-and-pressurized orange juice (207 $kPa-CO_2$ gas pressure, pressurized at 600 MPa for 10 min at $20^{\circ}C$) showed 0%. Pressurization at 400 MPa or higher decreased the population of microorganisms in the orange juice to less than 10 CFU/mL. Carbonated-and-pressurized orange juice showed slight decrease in vitamin C content when stored at both $4^{\circ}C\;and\;30^{\circ}C$. While heat-treated ($90^{\circ}C$ for 60 sec) orange juice showed 75% decrease in vitamin C content when stored at $30^{\circ}C$. L value (lightness) and b value (yellowness) of carbonated-and-pressurized orange juice were higher than those of heat-treated orange juice when they were stored at $4^{\circ}C$ for 30 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1307-1313
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• 2011

This study was conducted to evaluate the effects of irradiation temperature on the physicochemical and sensory properties of Tarakjuk, milk porridge. Tarakjuk was gamma-irradiated at different temperatures of $25^{\circ}C$ (in room), $4^{\circ}C$ (in ice), and $-20^{\circ}C$ (in dry ice) at a dose of 10 kGy, and then autoclaved at $120^{\circ}C$ for 15 min for comparison. pH and Hunter's color value of Tarakjuk were not changed by irradiation regardless of the temperature. However, the TBA (2-thiobarbituric acid) value decreased as irradiation temperature was decreased. The viscosity of Tarakjuk irradiated in dry ice was significantly higher than that irradiated at room temperature and in ice (p<0.05). For the sensory evaluation, there were no significant differences in overall acceptability between non-treated Tarakjuk and that irradiated in dry ice. Flavor pattern analysis using an electronic nose with a SAW (surface acoustic wave) sensor determined that the main peaks at retention times 3.88 and 7.34 sec were related with off-flavor induced by irradiation and unique flavor of Tarakjuk, respectively. These results indicated that irradiation at freezing temperature improved quality deterioration of Tarakjuk by gamma irradiation. However, sensory quality of Tarakjuk irradiated at freezing temperature was still lower than that of non-irradiated Tarakjuk. Therefore, further research is needed to improve the quality of Tarakjuk using combined treatment such as addition of antioxidants and vacuum packaging method.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.188-196
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• 2015

Endodontic management of an immature permanent tooth with dens invaginatus poses a challenge to efficient treatment planning for the clinicians. Because it is difficult to shape, disinfect, and seal the canal space effectively, teeth with complex root canal structures often require particularly extensive and thorough treatment approaches. The purpose of this case report was to share clinical insight from the results of short-term follow-ups after regenerative endodontic treatment with a dens invaginatus. Two immature maxillary lateral incisors with Oehlers type I and III dens invaginatus and infected necrotic pulp were treated using regenerative endodontic procedures. For the type III dens invaginatus case, an unusual approach toward redesigning the complex internal structure was taken, in order to have sufficient infection control and sealing. Cone-beam computed tomography (CBCT) and a surgical operating microscope were used to aid visualization and treatment. As a result, regenerative endodontic treatment appears to be effective for managing immature permanent teeth with complex dens invaginatus, and can lead not only to clinical and radiographic resolution, but also increased thickness of the dentinal walls.

• Child Health Nursing Research
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• v.19 no.1
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• pp.1-11
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• 2013

Purpose: This study was done to develop a scenario and evaluate student performance in simulation learning of care for children with respiratory distress syndrome in neonatal intensive care units. Methods: To test the application effect, a one group pre-test design was applied. The scenario based on actual patients and textbook material was developed through several meetings of experts. The scenario was used with 17 groups of 55 senior nursing students who participated voluntarily. Results: Contents were organized focusing on the nursing process for simulation learning. In the application of knowledge and skills, nursing students had high scores in the contents of observation of oxygen saturation, and care to relieve dyspnea. Participants' ability, especially in suction and oxygen supply in the evaluation of objective structured clinical examination was not adequate. There was a significant positive correlation between problem-solving ability and satisfaction in learning. Conclusion: The respiratory distress syndrome simulation scenario developed in this study was an effective tool to give students experience in problem solving and critical thinking ability under conditions similar to reality. The development of various scenarios for child nursing care is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.239-244
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• 2008

Paprika oleoresin (PO) and artificial Kimchi flavor (AKF) were added to Kimchi to improve the sensory qualities deteriorated by gamma irradiation in terms of color and flavor. Optimum concentration of both PO and AKF resulting from the sensory evaluation was 0.2%. The redness and capsanthin contents of Kimchi decreased by gamma irradiation at 25 kGy during storage at $35^{\circ}C$. However, the redness and capsanthin contents of gamma-irradiated Kimchi was increased by the addition of 0.2% PO, and maintained during the storage at $35^{\circ}C$ for 30 days. The result from the sensory evaluation indicated that sensory qualities of gamma-irradiated Kimchi were effectively improved by the addition of PO and AKF during storage at $35^{\circ}C$. Therefore, the combined treatment of additives (PO and AKF) and gamma irradiation can be considered as an effective method to improve the redness and sensory qualities of Kimchi sterilized by high-dose gamma irradiation.

• Food Science of Animal Resources
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• v.29 no.6
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• pp.695-701
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• 2009

This study was performed to evaluate the effectiveness of biological critical control points using the genetic profile of Escherichia coli isolates from pork cutting plants. Samples were collected from carcasses, equipment (knife, table, glove, transport belt, boning and skinning machine), the environment (wall and floor), and meat cuts during the cutting process from two plants. Pulsed-field gel electrophoresis (PFGE) was used to characterize the E. coli isolates. An identical genotype was detected from the carcasses, equipment, environment, and final meat cuts, and showed that the incoming carcasses, which were contaminated during transportation from slaughterhouses, were a major source of E. coli that was spread throughout processing. Also, consistent cross-contamination due to improper cleaning and disinfection procedures was another possibility. As a result, incoming carcasses and cleaning procedures should be considered critical control points in pork cutting plants, since a heating step is not used to inactivate microorganisms. Furthermore, the high rate (59.6%) of E. coli isolation indicates E. coli can be a good indicator in livestock processing plants even though it has genetic diversity.