• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.716-724
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• 2015

Trienzyme extraction coupled with microplate assay (Lactobacillus casei subsp. rhamnosus) was validated and applied for the determination of folate (vitamin B9) in Korean ancestral rite foods. Foods included five Guk (Tang), eleven Sookchaes, eight Jeoks, nine Jeons, six Jjims, and twenty desserts. Folate was detected in all samples: Guk (Tang) 4.62~18.84, Sookchae 6.13~48.40, Jeok 5.49~49.50, Jeon 6.96~30.77, Jjim 10.34~38.88, and desserts $3.33{\sim}49.55{\mu}g/100g$. The lowest folate content was observed in Sikhye ($3.33{\mu}g/100g$), whereas the highest was observed in Songhwa-dasik ($49.55{\mu}g/100g$). Folate analyses of certified reference materials, BCR-121 (whole meal flour) and BCR-487 (pig liver), showed good recoveries of 90.0% (0.45 mg/kg) and 92.4% (12.3 mg/kg), respectively. The recoveries (96.0 to 106.2%) obtained by analyzing eight spiked samples with different matrices also showed good accuracy. Both repeatability and reproducibility were less than 5%, indicating good precision. The quality control chart (n>30) obtained by running commercial folate fortified-wheat flour once a week for about 10 months showed that all assays were under control. All validation method and analytical quality control results showed that folate contents in Korean ancestral rite foods produced by microplate assay were reliable enough to be used for the construction of a national folate database.

• Journal of Life Science
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• v.25 no.1
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• pp.62-67
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• 2015

Myelophycus simplex Papenfuss is distributed over the northern Pacific and southern coast of Korea, and is a member of the brown algae family. The objective of this study was to investigate the effect of M. simplex methanol extract on adipocyte differentiation and adipogenesis in 3T3-L1 preadipocytes. Treatment with M. simplex methanol extract significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by a decrease in lipid droplet content observed by Oil Red O staining. Also, the M. simplex methanol extract significantly suppressed the triglyceride content of 3T3-L1 preadipocytes in a dose-dependent manner. Treatment with 300 and $500{\mu}g/ml$ of M. simplex methanol extract caused a 42% and 76% reduction in lipid droplet content, respectively. In order to understand the anti-adipogenic effects of M. simplex methanol extract, the changes in the expression of several adipogenic transcription factors, including peroxisome proliferator-activated receptor (PPAR) ${\gamma}$-cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding protein (C/EBP) ${\alpha}$ and ${\beta}$, were investigated using immunoblotting. M. simplex suppressed the expression of $PPAR{\gamma}$, $C/EBP{\alpha}$, and $C/EBP{\beta}$ proteins compared with control. Therefore, the results of this study suggest that M. simplex methanol extract inhibits adipocyte differentiation and thus may have applications as a potential source for an anti-obesity functional food agent.

• Food Science and Preservation
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• v.24 no.7
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• pp.983-991
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• 2017

This study was performed to update the National Standard Food Composition Table (NSFCT) published by Korea Rural Development Administration, especially focusing on vitamin $B_{12}$ for Korean pork. Total 7 primal and 22 retail fresh cuts of Korean pork were analyzed for vitamin $B_{12}$ and the applied immunoaffinity-HPLC was validated. Vitamin $B_{12}$ assay by immunoaffinity-HPLC obtained recoveries over 95% and coefficient variations of precision below about 10%, which met the limits required for validation acceptance. Limits of detection and quantification of immunoaffinity-HPLC were 0.01 and $0.33{\mu}g/100g$, respectively. Quality control chart showed that analysis performance was excellent during the entire of study. Vitamin $B_{12}$ contents of pork cuts significantly varied depending the types of primal and its retail cuts (p<0.05). Belly, Boston butt, rib cuts showed relatively high vitamin $B_{12}$ contents compared to other primal cuts. Vitamin $B_{12}$ content of pork retail cuts were also significantly different within the same primal cuts (p<0.05). Among 22 retail cuts, the highest vitamin $B_{12}$ was observed in Tosisal in belly primal part ($0.98{\mu}g/100g$) while both Aldeungsimsal in loin and Hongdukkaesal in hide leg were the lowest by $0.33{\mu}g/100g$. This study provides reliable vitamin $B_{12}$ data for the Korean pork fresh cuts through standard sampling, method validation and analytical quality control, which would be used for update of Korean NSFCT.

• Journal of Life Science
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• v.24 no.3
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• pp.297-303
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• 2014

The effects of Eisenia bicyclis extracts on osteoblast differentiation and osteoclast formation were investigated. The proliferation of MC3T3-E1 osteoblastic cells was tested in an MTT assay. Treatment with E. bicyclis ethanol extract increased cell proliferation by approximately 128% at a concentration of 10 ${\mu}g/ml$. The ALP activities in the MC3T3-E1 cells was 179% higher when the E. bicyclis ethanol extract was processed at a concentration of 50 ${\mu}g/ml$. The proliferation of RAW 264.7 osteoclastic cells decreased significantly in response to treatment with the E. bicyclis extracts. Moreover, the proliferation of the RAW 264.7 osteoclastic cells treated with E. bicyclis hot water extract decreased by nearly 80%. In addition, the E. bicyclis extract reduced the number of tartrate-resistant acid phosphatase-positive (TRAP+) multinucleated cells from osteoclastic RAW 264.7 cells. These results indicate that E. bicyclis extracts have an anabolic effect on bone through the promotion of osteoclast differentiation and suggest that the extracts could be used in the treatment of common metabolic bone diseases.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.2
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• pp.72-89
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• 2012

This study aimed to reconsider the theory that the renowned Amisan(峨眉山) terraced garden at north of Gyotaejeon(交泰殿) was artificially made, by reviewing the historical records and drawings. It has been widely accepted that Amisan was made of the digged soil from Gyeonghoeji(慶會池). But several arguments about artificial mountain theory of Amisan that completely not be found in historical records have been raised in this study. The results were summarized as follows; the inherent contradiction in existing opinion, the discordance between the time of building Gyeonghoeji and Gyotaejeon, the existence of the mountain range which connect Baekaksan and Amisan appeared in Dohyeong(圖形), historical documents written in the years of kingdoms of Youngjo(英祖) and Gojong(高宗), a high position seen from Heungbogjeon(興復殿) in the north Amisan through the wall in the east but impassable, an opinion about realization Amisan as geomantic term of Amisa(蛾眉砂) at the time of Gyeongbok Palace reconstruction, and preservation of the mountain range in Gyeongbok Palace that comes from the result of the arguments in main mountain of Gyeongbok Palace in the year of Sejong(世宗). In addition, it was investigated why the slop in the north of Gyotaejeon was named as Aminsan and why the artificial mountain theory is appeared and made a conclusion that the Amisan comes from the change of the pronunciation of the geomantic term "Amisa", and modeling the yijing[意景] of Amisan which is a sacred place of Taoism and Buddhism in Sichuan[四川] of Chinaand the view of construction to mean defeating a spirit of smallpox which had to be cured. And it seems to be a result which retroactively applied the artificial mountain theory of Amisanis the technique of 'constructing mountain with digged pond dirt' to the relationship between Gyeonghoeji and Amisan. The greater part of mountain range which was connecting with Baekaksan and Amisan was seriously disconnected with large scale of exposition by the Japanese colonial period in 1915. But low slope is kept about 70 meters along the trail northeast of Gyotaejeon. Accordingly, it is judged that the range has not been entirely destroyed. And according to the result of elevation analysis, discontinuous slope form certain axis is found, so the mountain range of Amisan is approximately estimated. This basic research about the mountain range of Amisan might provide a critical clue about restoration of topography in Gyeongbok Palace.

• Food Science and Preservation
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• v.24 no.8
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• pp.1103-1112
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• 2017

This study was performed to investigate the effects of different cooking methods (boiling, roasting, stir-frying, and deep-frying) on folate retention in 6 kinds of mushrooms (Beech-, button-, Juda's ear-, oak-, oyster-, and winter-mushrooms) frequently consumed in Korea. In order to assure reliability of analytical data, trienzyme extraction-L casei method was verified and analytical quality control was also evaluated. Folate contents of mushrooms varied by 6.04-64.82 g/100 g depending on the type of mushrooms. and were significantly affected by cooking methods. Depending on cooking methods, folate contents of mushrooms decreased by 22-48%, 2-31%, and 17-56% for Juda's ear-, oak- and oyster-mushrooms, respectively, while 17-90% of folate was increased in Beech mushroom. Overall, the largest weight loss was found in boiled mushrooms, but the lowest one in deep-fried samples. True folate retention rates considering processing factor were less than 100% for all cooked mushrooms except for Beech samples. Overall, folate loss was the largest by boiling with water but the smallest by deep-frying. Both accuracy and precision of trienzyme extraction-L-casei method were excellent based on a recovery close to 100% and coefficient variations less than 3%. Quality control chart of folate analysis (n=26) obtained during the entire study and an international proficiency test (z-score=-0.5) showed that trienzyme extraction-L casei method is reliable enough for production of national folate database.

• Food Science and Preservation
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• v.14 no.3
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• pp.288-293
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• 2007

Intermediate moisture-apple snail products were prepared by adding glycerol, sorbitol, kiwi, or pineapple(2% or 5% w/w), as tenderizers, and by drying at $4^{\circ}C$ for 24 hr. The effects of the tenderizers on textural and sensory properties of the apple snail products at intermediate moisture levels were investigated. Moisture content and water activity of the products were ranged from 26.25 to 34.48% and from 0.83 to 0.87, respectively. The addition of glycerol significantly lowered water activity of apple snail samples compared to control prepared without tenderizers. On the other hand, significant increases in moisture content and water activity were observed in apple snail samples treated with kiwi or pineapple(p<0.05). All apple snail samples treated with tenderizers showed a lower shear force than did the control. Apple snail samples treated with 5%(v/v) glycerol showed a higher equilibrium moisture content than did the other samples. SDS-PAGE indicated that proteolytic enzymes in kiwi and pineapple clearly changed the structure of the myosin heavy chain and actin filaments of myofibrillar protein in apple snail samples. Intermediate moisture apple snail samples treated with tenderizers showed significantly improved overall sensory characteristics. The highest overall acceptability was obtained from apple snail samples treated with 5% pineapple, while the lowest overall acceptability was noted in the control sample. This study demonstrates that an acceptable apple snail, with intermediate moisture content, may be produced by using tenderizers at appropriate concentrations.

• Food Science and Preservation
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• v.24 no.1
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• pp.84-92
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• 2017

Chicken breast jerky (CJ) was prepared by drying chicken breast at $50^{\circ}C$ for 9 hrs after marinating it in a various sweetening sauce including white sugar (WS), brown sugar (BS), rice syrup (RS), fructooligosaccharide (FO), pineapple concentrate (PC), Rubus coreanus extract (RCE), or honey (H), and its physicochemical and sensory properties were investigated. The CJ was found to contain 22.5-25.0% moisture, 41.0-46.6% protein, and 0.4-1.0% fat, which indicates that it could serve as a high-protein and low-fat snack. The type of sweeteners significantly affected the yield, pH, total viable cell count, and water activity of the CJ, showing ranges of 40.9-50.1%, 5.2-5.9, $2.5-6.2{\times}10^4CFU/g$, and 0.74-0.81, respectively. Both the water activity and pH were the lowest in CJ-RCE where of the highest in CJ-WS. The cohesiveness, springiness, and chewiness of the CJ significantly differed depending on the type of sweeteners (p<0.05). CJ-RCE showed the best taste and overall acceptability in a sensory test. After storage at $50^{\circ}C$ for 2 weeks, thiobarbituric acid reactive substance (TBARS) content (58.3 malondialdehyde (MDA) mg/kg) of CJ-RCE was much lower than those of control beef (75.6 MDA mg/kg) and pork jerky (98.0 MDA mg/kg), showing the good oxidative stability of CJ-RCE. Overall, marination in RCE sauce was suitable for the preparation of CJ with good quality in terms of its water activity, fat and protein contents, sensory property and oxidative stability.

• Journal of Life Science
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• v.25 no.4
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• pp.456-462
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• 2015

We investigated the effects of fermented Sargassum thunbergii (FST) on platelet aggregation and serum lipid levels in rats made obese by a high fat diet. Six-week-old male SD-rats were randomly assigned to four groups as CON, HF-CON induced by high fat diet (HF), ST supplemented with HF (HFST100), and the fermented ST supplemented with HF group (HF-FST100). After 6 weeks, the results showed that the final weight and weight gain had decreased in the HF- FST100 group compared to the HF-CON group. Also, the food efficiency ratio was significantly reduced in the HF-FST100 group compared to HF-CON. The organ weights other than heart and spleen were significantly lower in the HF-FST100 group than in the HF-CON group. The levels of serum GOT and GPT significantly decreased in the HF-FST100 group over the HF-CON group. In addition, the total cholesterol, triglyceride and LDL-cholesterol levels were lower in the HF-FST100 group than in HF-CON, while the HDL-cholesterol level was higher in the HF-FST100. The ability of platelet aggregation of groups supplemented with FST was lower than the HF-CON group. These results suggest that FST may be beneficial in improving lipid profile and platelet aggregation in obesity.

• Journal of Life Science
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• v.26 no.8
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• pp.955-962
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• 2016

Fish-meat gel is an intermediate product used in a variety of surimi-based seafood. One of the most-used raw materials of fish-meat gel is Alaska Pollock due to its high-quality meat in terms of gel strength and texture. However, increasing demand for fish-meat gel, along with overexploitation of the wild catch Alaska Pollock, has put the industry in need of low-cost sustainable alternative sources for fish-meat gel. Pagrus major (PM) is a widely aquacultured fish known for having white meat that is low in fat. The current study compares the quality of fish-meat gel prepared from aquacultured PM to that of high and mid-grade Alaska Pollock fish-meat gel. Gels were compared in terms of gel strength, texture, color, and protein pattern. Results indicated that fish-meat gels prepared from PM were superior to Alaska Pollock fish-meat gels with regard to gel strength, hardness, springiness, chewiness, cutting strength, and breaking force. In addition, although not matching in quality, PM exhibited a cohesiveness, whiteness, and expressible moisture content comparable to Alaska Pollock of both grades. Protein pattern analysis also showed that PM and Alaska Pollock fish-meat gels had similar protein profiles before and after gel preparation. Therefore, P. major is suggested as a potential substitute for Alaska Pollock in fish-meat gel production.