• Korean Journal of Environment and Ecology
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• v.33 no.1
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• pp.28-51
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• 2019

The purpose of this study was to analyze forest vegetation structure in Marugeum (the ridge line) area between Dakmokryeong and Daetjae in Baekdudaegan through vegetation classification, importance value, species diversity, and CCA using the data that were collected from 245 quadrates through Braun-Blanquet vegetation survey method from May to September in 2017. The results of the forest vegetation classification identified 8 vegetation units with Quercus mongolica community group at the highest level. Q. mongolica community group was classified into the Cornus controversa community, Buxus koreana community, Sasa borealis community, Abies nephrolepis community, and Q. mongolica typical community. C. controversa community was further classified into Quercus dentata group, Filipendula glaberrima group, Larix kaempferi group, and C. controversa typical group. The result of the important value analysis showed that Q. dentata had the highest importance value at 19.1% in vegetation unit 1 while Q. mongolica had the highest importance value at 22.7%, 38.3%, 25.6%, 41.3%, 27.9%, and 41.6% in vegetation unit 2, 4, 5, 6, 7, and 8, respectively, and L. kaempferi had the highest importance value at 27.6% in vegetation unit 3. As such, Q. mongolica species generally represented the communities of Marugeum (the ridge line) area of Dakmokryeong to Daetjae in Baekdudaegan. The results of species diversity showed that vegetation unit 1 and 2 were 3.305 and 3.236, respectively, which were relatively higher than other vegetation units. It was considered that this result was due to the influence of high emergence of present species. The results of the CCA analysis of the correlations between biotic environmental factors and vegetation types showed that vegetation unit 1 was mainly correlated with the megaphanerophyte ratio and vine plant ratio. In the correlations between abiotic environmental factors and vegetation types, vegetation unit 7 was significantly correlated with altitude. From the perspective of ecological management, vegetation unit 5 represented by B. koreana community was inhabited by a variety of plants due to the species composition and location environment due to the geological characteristics that are typical of limestone area. Vegetation unit 7 represented by A. nephrolepis community was typified as subalpine vegetation widely distributed by relict species and endemic species. We concluded that it is necessary to manage these vegetation units with an ecologically differentiated approach.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.261-272
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• 2018

This study was conducted to evaluate the difference in the quality of chicken thigh meat from conventional and animal welfare farms during refrigeration storage over 9 days. Chicken thigh meat from conventional (CTC, n = 30) and animal welfare farms (CTW, n = 30) was tested. The pH value was significantly lower in CTW (6.28) than in CTC (6.37) on day 1; however, no significant differences were found on subsequent days. The yellowness of CTW was higher than that of CTC on day 1, but CTW showed lower yellowness than did CTC on day 7 and 9. The cooking loss, water holding capacity, lightness, redness, and coliform levels of CTC did not show any significant difference when compared with CTW during storage. The shear force of CTW was significantly higher than that of CTC on day 1, 3, 7, and 9. Total microorganism and coliform in CTC and CTW increased with increasing storage days. On day 7 and 9, the total microorganism level of CTW was lower than that of CTC. The thiobarbituric acid value of CTW was lower than that of CTC on day 9. The volatile basic nitrogen (VBN) of CTW was lower than that of CTC during storage. Anserine content and 1,1-diphenyl-2-picryl-hydrazyl(DPPH) scavenging activity of CTW was significantly higher than CTC on day 1. These results suggest that CTW stayed fresher for longer than did CTC because of low total microorganism level on day 7 and 9, and VBN during refrigerated storage.

• Korean Journal of Remote Sensing
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• v.34 no.6_4
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• pp.1479-1488
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• 2018

On September 3rd 2017, strong artificial seismic signals from North Korea were detected in KMA (Korea Meteorological Administration) seismic network. The location of the epicenter was estimated to be Punggye-ri nuclear test site and it was the most powerful to date. The event was not studied well due to accessibility and geodetic measurements. Therefore, we used remote sensing data to analyze surface changes around Mt. Mantap area. First of all, we tried to detect surface deformation using InSAR method with Advanced Land Observation Satellite-2 (ALOS-2). Even though ALOS-2 data used L-band long wavelength, it was not working well for this particular case because of decorrelation on interferogram. The main reason would be large deformation near the Mt. Mantap area. To overcome this limitation of decorrelation, we applied offset tracking method to measure deformation. However, this method is affected by window kernel size. So we applied various window sizes from 32 to 224 in 16 steps. We could retrieve 2D surface deformation of about 3 m in maximum in the west side of Mt. Mantap. Second, we used Pleiadas-A/B high resolution satellite optical images which were acquired before and after the 6th nuclear test. We detected widespread surface damage around the top of Mt. Mantap such as landslide and suspected collapse area. This phenomenon may be caused by a very strong underground nuclear explosion test. High-resolution satellite images could be used to analyze non-accessible area.

• Journal of Life Science
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• v.29 no.2
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• pp.239-247
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• 2019

The aim of this study was to improve the efficacy and functionality of Viola mandshurica (VM). A water suspension of VM power was fermented for 72 hr with Bacillus methylotrophicus CBMB205 (BM) and Leuconostoc pseudomesenteroides NRIC1777 (LP) isolated from kimchi. The antioxidant activity and reducing power of fermented VM, its total phenolic and flavonoid compounds, as well its inhibitory activity on ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase were determined and compared to those of non-fermented VM (NVM), a negative control. The total phenolic and flavonoid compounds of VM fermented with BM and LP were higher than those of NVM by 1.4, 1.17, and about 3 times. There was no difference in 2, 2'-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity between fermented VM and NVM. However, there was a 2.1- and 1.6-fold increase in 2, 2'-azino-bis-(3-ethylbenzothzoline-6-sulfonic acid) (ABTS) radical scavenging activity in VM fermented with BM and LP, respectively. The reducing power of BM was 1.6 times as high as NVM, but no significant difference was found between LP and NVM. Fermented VM's inhibitory activity on ${\alpha}$-amylase, ${\alpha}$-glucosidase, and pancreatic lipase was much higher than that of NVM. Fermenting VM with BM was superior to fermenting it with LP, except flavonoid content. Taken together, VM fermented with BM could be used as a functional food and as an additive to cosmetics.

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.87-96
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• 2022

Recently, the purchase of fresh-cut produce and meal kits has increased. Ready-to-eat (RTE) fresh-cut products have potentially hazard of cross-contamination of various microorganisms in the processes of peeling, slicing, dicing, and shredding. There are frequent cases of protozoa food poisoning, such as Cyclospora and Cryptosporidium, caused by fresh-cut products. The objective of the study is to investigate the microbiological qualities of various types of RTE fresh-cut products in the domestic on/offline markets. RTE fresh-cut fruits cup (n=100), fresh-cut vegetables (n=50), and vegetables in meal kits (Vietnamese spring rolls and white radish rolls kits, n=50) were seasonally analyzed. The contamination levels of hygienic indicator organisms, yeast and mold (YM), and foodborne pathogens (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7) were monitored. Overall, the lowest microbiological qualities of meal kits vegetables were observed, followed by RTE fresh-cut fruits cup and fresh-cut vegetables. Contamination levels of total aerobic bacteria, coliforms, and YM in meal kits vegetables were 5.91, 3.90, and 4.71 logs CFU/g, respectively. From the qualitative analysis, 6 out of 200 RTE fresh-cut products (3%) returned positive result for S. aureus. From the quantitative analysis, the contamination levels of S. aureus in purple cabbage from a meal-kit and fresh-cut pineapple were below the acceptable limit (100 CFU/g). Staphylococcus enterotoxin seg and sei genes were detected in RTE fresh-cut celery and red cabbage from meal-kits, respectively. S. aureus contamination must be carefully controlled during the manufacturing processes of RTE fresh-cut products. Neither Cyclospora cayetanensis nor Cryptosporidium parvum was detected in the samples of RTE fresh-cut products and vegetables from meal-kits from the Korean retail markets.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.207-216
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• 2021

This study was conducted to determine the nutritional quality of two newly-developed native chicken strains, compared to the commercial Korean native chicken. A total of 600 chickens (CON: Hanhyup No. 3, CL1: candidate line C, CL2: candidate line D) raised under the same conditions were slaughtered at either 5 or 12 weeks. Leg meat was then obtained and analyzed for its physicochemical properties. The results showed that regardless of the growing period, there was no variation in proximate composition (P>0.05), except for crude protein, between strains. Water holding capacity did not differ between strains at either slaughter age; however, it was significantly lower in the 12-week group than in the 5-week group (P≤0.05). For both skin and muscle color, a^* and b^* values were lower at 12 weeks than at 5 weeks (P≤0.05). DPPH radical-scavenging activity tended to be lower at 12 weeks than at 5 weeks (P≤0.05). Furthermore, all chickens slaughtered at 5 weeks were found to have greater contents of linoleic acid (18:2) and polyunsaturated fatty acids (PUFA) and lower atherogenicity and thrombogenicity indices than those slaughtered at 12 weeks (P≤0.05). However, anserine, betaine, and glucose were more concentrated among the lines at 12 weeks than at 5 weeks (P≤0.05). In conclusion, the quality traits of native chickens were distinct by different production stages rather than chicken lines.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.181-186
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• 2021

In this study, the physical characteristics, antioxidant activity, and stability of muffins prepared with acai berry concentrate-loaded nanocapsules were evaluated. The size of the acai berry nanocapsules significantly increased with higher chitosan and lower Arabic gum concentrations. Based on the total phenolic content and antioxidant activity, the free acai berry concentrate showed significantly stronger antioxidant activity than that of the acai berry concentrate-loaded nanocapsules using chitosan and Arabic gum because of the entrapment of encapsulated acai berry. The physicochemical and textural properties of the muffin prepared with acai berry concentrate-loaded nanocapsules did not show notable differences compared with the control muffin. However, the stability of acai berry concentrate in terms of total phenolic content and antioxidant activity was effectively enhanced by nanoencapsulation while baking the muffin. This study suggested that acai berry concentrate-loaded nanocapsules are potential ingredients for bakery products.

• Journal of Life Science
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• v.33 no.5
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• pp.391-396
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• 2023

Milk is an emulsion, improving texture of surimi mixture and able to suppress off flavors and abnormal tastes. Therefore, this study aimed to identify the effective properties of milk in the preparation of a surimi mixture for 3D printing. The sensory and physical properties of surimi mixtures containing 0%, 20 wt%, and 40 wt% milk were evaluated, where the unheated surimi mixture with added milk demonstrated increased firmness and adhesiveness compared to the negative control group. In addition, the hardness, adhesiveness, gumminess, and chewiness of the mixture containing 40% milk were highest, but springiness, cohesiveness, and resilience were lowest. In the sensory evaluation, as the amount of milk increased, a fishy smell, abnormal taste and texture improved, hardness and preference increased as well. From these results, it was confirmed that a surimi mixture can be prepared with milk to improve its physical and sensory properties for 3D printing when compared to the negative control mixture. In particular, it was revealed that the physical properties and preference of the surimi mixture are best when prepared with 40% milk.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.2
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• pp.87-94
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• 2023

Fresh bakery products are widely consumed worldwide and therefore particular requirements for their quality characteristics have been established. The shelf life of bakery products is mainly subjected to microbial spoilage and staling. This study investigated the optimum conditions of modified atmosphere packaging (MAP) application to extend the shelf life of the bakery products. The gas conditions of the headspace in 'Baumkuchen' cake were 0, 30, 70, and 100% CO₂ concentrations and stored at 30℃ for 5 days. The bakery samples were evaluated weight loss, hardness, color change, pH and total aerobic bacteria, yeast and molds count throughout the storage period. Values of the weight loss and hardness were increased over the storage period, meanwhile pH was significantly decreased. However, no significant color changes were observed during storage. It was also found no significant difference between the different gas treatments. Total aerobic bacteria count of the stored samples after day 5 was increased by 6.94 log CFU/g in the air filled package, compared to 6.20 log CFU/g in the 100% CO₂ filled package and 6.02 log CFU/g in the 70% CO₂ filled package. Yeast and molds count were 3.65 log CFU/g in air filled package, 2.66 log CFU/g in 100% CO₂ filled package, 2.64 log CFU/g in 70% CO₂ filled package, 2.86 log CFU/g in 30% CO₂ filled package and 3.31 log CFU/g in 100% N₂ filled package on day 2. In conclusion, it was shown that 70% and 100% CO₂ treatments in the package were effective to reduce microbial growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.32-39
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• 1981

In order to study the genetic system of the blast resistant varieties, the conidial suspension of mutant races of T-2$^{+t}$, N-2$^{+t}$, C-8$^{+t}$ was inoculated at 4-5 leaf stage by injector for F_2 seedlings from the crosses between seven resistant varieties and four maker lines easily detectable at seedling stage. The results are summarized as follows; 1. The fertility of cross between Semi-dwaf testers and Indica resistant varieties except Carreon was about 74 percents. 2. The segregation modes of resistance varied with varieties and blast races. However, the resistance was expressed as dominance in all cases. Tetep, Tadukan and Carreon showed more complicated segregation for resistance than that of the bred lines. 3. For blast races used, four segregation ratios such as 3:1, 9:7, 13:3 and 37:27 were found in the Tatukan, Tetep, and IR747, and three segregation ratios such as 3:1, 13:3 and 15:1 in the Carreon, and two segregation ratios of 3:1 and 13:3 with Suweon 287, Suweon 288, and Iri342. 4. In the segregation of the resistance to the each races, the ratios of 3:1, 13:3, 15:1 were fitted to T-2$^{+t}$, and the ratios of 3:1, 13:3, 9:7 and 37:27 to N-2$^{+t}$ and C-8$^{+t}$. 5. Suweon 287, Suweon 288 and Iri342 carried one simple dominant gene and inhibitor gene was considered in some cross combinations. Meanwhile Tadukan, Tetep and IR747 seemed to carry one to three resistant genes, and in some cross combinations, the expression of these genes were simple dominant, inhibiting, duplicating and complimentary action. 6. Resistance genes to blast races, T-2$^{+t}$, N-2$^{+t}$ and C-8$^{+t}$ in the Tadukan, Tetep, Carreon, Suweon 287, Suweon 288 and Iri342 were found to be independent with the linkage group of II(lg), VIII(la), XI(bc), and XII(gl).bc), and XII(gl).