• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.426-433
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• 2009

Fish scales have potential in functional food preparation due to their antioxidant and antihypertensive properties. We investigated the angiotensin I converting enzyme (ACE) inhibitory activity of Tilapia mossambica scale extracts. Hydrolysates of tilapia scales were prepared by enzymatic extraction using five proteases (${\alpha}$-chymotrypsin, Alcalase, Kojizyme, Protamex and trypsin) after scales were treated with hot water for 3 hr. Scale enzymatic hydrolysates prepared using both hot water and enzyme treatments exhibited elevated hydrolysis (about 25%-55%) compared to only enzyme treatment (about 15%-45%). Enzymatic hydrolysates (1 mg/mL) prepared by both hot water and enzyme treatments also showed significantly increased ACE inhibitory activities from about 20%-75%. The pattern of ACE inhibitory activities was similar to the degree of hydrolysis. Alcalase and ${\alpha}$-chymotrypsin hydrolysates displayed the highest ACE inhibitory activities ($IC_{50}$ = 0.83 mg/mL and 0.68 mg/mL, respectively). In addition, the ACE inhibitory effects of $IC_{50}$-chymotrypsin hydrolysates increased with decreasing molecular weight (5 kDa>, 10 kDa> and 30 kDa>), with the 5 kDa> fraction displaying the highest ACE inhibitory activity (about 89.9% and $IC_{50}$ = 0.1 mg/mL). We suggest that the peptide compounds of enzymatic hydrolysates prepared from tilapia scale enhances ACE inhibitory activity and might be useful as an antihypertensive material.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.417-425
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• 2009

The potential utility of fish scales to the functional food industry has been investigated due to its antioxidant and antihypertensive characteristics. In this study, we report on the reactive oxygen species (ROS) scavenging and angiotensin I converting enzyme (ACE) inhibitory activities of gelatin hydrolysates processed from Branchiostegus japonicus scales, which are also high in protein content (about 46.1%). We prepared the enzymatic gelatin hydrolysates with four proteases (${\alpha}$-chymotrypsin, Alcalase, Neutrase and trypsin) from B. japonicus scale gelatin, which was prepared according to different reaction times, substrate/enzyme ratios and substrate concentrations. The enzymatic hydrolytic degrees of the gelatin increased time-dependently up to 6 hrs, while the Alcalase gelatin hydrolysates showed the highest hydrolysis degrees compared to the others. Furthermore, gelatin hydrolysates of Neutrase and ${\alpha}$-chymotrypsin showed the highest DPPH radical and $H_2O_2$ scavenging activities ($IC_{50}$ value; 9.18 mg/mL and 9.74 mg/mL), respectively. However, the activities were not significant (P<0.05). We also observed that the four gelatin hydrolysates significantly increased ACE inhibitory activities from approximately 20% to 60% (P<0.05), Among them, the Alcalase gelatin hydrolysates showed the higher ACE inhibitory activity ($IC_{50}$ value; 0.73 mg/mL) compared to the others. These results suggest that the enzymatic gelatin hydrolysates prepared from B. japonicus scales may possess a potentially useful function as an ACE inhibitory agent. As such, the utility of B. japonicus scales should be given due consideration for application in the functional food industry.

• Journal of Life Science
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• v.26 no.9
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• pp.1074-1081
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• 2016

Mistletoes are hemi-parasitic plant growing on different host tree and shrubs. They are traditionally used in folkloric medicine for the treatment of diarrhea, cough, diabetes, hypertension, cancer and skin infection. The purpose of this study was to determine the contents of phenolics and antioxidant activity of 70% ethanol, 100% methanol and hot water extracts of Jeju camellia mistletoe (Korthalsella japonica Engl.). Ethanol was most effective in extracting total phenols (7,427 mg gallic acid equivalent (GAE)/100 g) and flavonoid (1,777 mg rutin equivalent (RE)/100 g). The free radical scavenging activity, 1,1-diphenyl-2-picryl hydrazyl (DPPH) (EC₅₀ = 7.8 mg/ml) and hydrogen peroxide (H₂O₂) (EC₅₀ = 1.4 mg/ml), and the capacity for chelating metal ions (EC₅₀ = 8.0 mg/ml) and reducing power (EC₅₀ = 14.9 mg/ml) of the samples also higher in ethanolic extracts. The strong correlation (r² = −0.996～−0.881) between antioxidant capacities and the phenolic contents implied that phenolic compounds are a major contributor to the antioxidant activity of the ethanolic extracts of Jeju camellia mistletoe. As conclusions, Jeju camellia mistletoe contains bioactive substances with a potential for reducing the physiological as well as oxidative stress and this could explain the suggested cancer preventive effect of these plants as well as their protective role on other major diseases.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.2
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• pp.45-60
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• 2024

This study aims to analyze the accidence of tourist safety accidents in Jeju using GIS and to expand the understanding of tourist safety accidents in the Jeju area. For this purpose, the eastern part of Jeju was selected as the study area, with the research period set for the entire year of 2021. The analysis utilized data on tourist safety accidents and emergency dispatch data resulting from these accidents in Jeju throughout 2021. Based on this safety accident data, an initial analysis was conducted on the accidence of tourist safety accidents across Jeju Island. This analysis identified patterns in the occurrence of tourist safety accidents by month, time, and location. Subsequently, using spatial data, grid analysis, and overlay analysis, the study examined the status of tourist safety accidents and emergency dispatches to identify vulnerable areas. Through this GIS analysis of tourist safety accidents, the study highlights the need for preventive and responsive measures considering the activity characteristics of tourists. It emphasizes the necessity of proactive preventive measures such as inspecting tourist facilities and promoting safety accident prevention, particularly in vulnerable areas..

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.128-140
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• 2021

This study applied the theory of Landscape Ecology to representative resources of Jeju Olle-gil, which is a representative subject of walking tourism, to identify ecological characteristics and to establish a technique for landscape ecological analysis of Olle-gil resources. Jeju Olle Trail type based on the biotope type, major land use, vegetation status around Olle Trail and roads were divided into 12 types. Based on the type of ecological tourism resource classification, the Jeju Olle-gil walking tourism resource classification was divided into seven types of natural resources and seven types of humanities resources, and each resource was characterized by Geotope, Biotope, and Anthropopope, just like the landscape ecology system. Geotope resources are strong in landscape characteristics such as coast and beach, rocks, bedrocks, waterfalls, geology and Jusangjeolli Cliff, Oreum and craters, water resources, and landscape viewpoints. The Biotope resources showed strong ecological characteristics due to large tree and protected tree, Gotjawal, forest road and vegetation communities, biological habitat, vegetation landscape view point. Antropotope include Culture of Jeju Haenyeo and traditional culture, potting and lighthouses, experience facilities, temples and churches, military and beacon facilities, other historical and cultural facilities, and cultural landscape views. Jeju Olle Trail The representative resources for each type of Jeju Olle Trail are coastal, Oreum, Gotjawal, field and Stonewall Fencing farming land, Jeju Village and Stone wall of Jeju. In order to learn about the components and various functions of the resources representing the Olle Trail's ecological culture, the landscape ecological technique was interpreted. Looking at the ecological and cultural characteristics of coastal, the coast includes black basalt rocks, coastal vegetation, coastal grasslands, coastal rock vegetation, winter migratory birds and Jeju haenyeo. Oreum is a unique volcanic topography, which includes circular and oval mountain bodies, oreum vegetation, crater wetlands, the origin and legend of the name of Oreum, the legend of the name of Oreum, the culture of grazing horses, the use of military purposes, the object of folk belief, and the view from the summit. Gotjawal features rocky bumps, unique microclimate formation, Gotjawal vegetation, geographical names, the culture of charcoal being baked in the past, and bizarre shapes of trees and vines. Field walls include the structure and shape of field walls, field cultivation crops, field wall habitats, Jeju agricultural culture, and field walls. The village includes a stone wall and roof structure built from basalt, a pavilion at the entrance of the village, a yard and garden inside the house, a view of the lives of local people, and an alleyway view. These resources have slowly changed with the long lives of humans, and are now unique to Jeju Island. By providing contents specialized for each type of Olle Trail, tourists who walk on Olle will be able to experience the Olle Trail in depth as they learn the story of the resources, and will be able to increase the sustainable use and satisfaction of Jeju Olle Trail users.

• Culinary science and hospitality research
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• v.14 no.2
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• pp.1-17
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• 2008

This study analyzed the factors related to the stress which the top-rated chefs in Jeju suffer and conducted the multiple regression analysis to look into the effect of job-related stress on the stress reaction and the satisfaction with job, in order to examine the effect of job-related stress faced by hotel kitchen employees in performing duties and determine the effect of job-related stress on the reaction of individuals in the peculiar environment of a kitchen in a hotel. Job-related stresses were classified into five factors which were physical, individual, vocational, organizational, and social. The result of regression analysis, which was performed to figure out the effect of job-related stress on the stress reaction and the satisfaction with the job, indicated that the physical factor of job-related stress had the greatest effect on the physiological reaction, followed by the organizational factor, individual factor, and social factor, while the organizational factor of job-related stress had the greatest effect on the psychological reaction, followed by the individual factor, social factor, vocational factor, and physical factor. Meanwhile, the vocational factor of job-related stress had the greatest effect on behavioral re-action, followed by organizational factor and individual factor. The vocational factor of job-related stress had the greatest effect on the satisfaction with the job, followed by individual factor, organizational factor, social factor, and physical factor.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.43-54
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• 2018

The residential population of Jeju Island has increased more than 10% for last 10 years. Especially, the tourist population is more than twice comparing to 2005. The population growth of Jeju has brought about large-scale urban development and increased land demands for tourism services. The goal of this study is to analyze the human, social, and environmental status of Jeju Island and to evaluate the environmental capacity of land use using ecological footprint (EF) model. This study shows the changes in ecological deficits of Jeju Island through estimating ecological productive land (EPL) considering EF from 2005 to 2015. The categories of total EF consists of food land, built-up land, forestry, and energy consumption. In order to reflect the characteristics of resort island, we consider not only residential population but also tourist population who can increase land demands. The outputs of this study also provide the potential excess demands of EPL and suggest needs of sustainable management plans for the limited land of Jeju Island.

• The Research Journal of the Costume Culture
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• v.23 no.1
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• pp.45-62
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• 2015

This study is to develop cultural products based on 'Jeju Choga', which means the traditional houses in Jeju. For the product development, old literature review, field surveys, and consumer surveys were employed. Through old literatures and field surveys, the unique and visual characteristics of Jeju Choga were confirmed: A thatched roof with lattice pattern, a side wall and fences with porous stones, a 'Jungnang' serving as a gate, and a 'Pungchai' preventing strong sola radiation and 'Ollai' meaning a narrow street in front of the Choga. As a results of consumer survey conducted before the development of products, consumers highly recognized and associated Jeju Choga as Jeju representative image. The six basic patterns of Jeju Choga were drawn and eight textile designs were created through the repeated arrangements of the basic patterns. Using the created textile designs and digital printing method, the eleven new fabrics with the patterns of Jeju Choga were developed. The various kinds of ten bags and tow wallets made with the new fabrics. As a result of consumer evaluation for the twelve products made in this study, the scores of preference and purchase intention were above the average work for the most products of them. In particular, the preference and purchase intention of the square shoulder bag, the big-size shopper bag, and the small-size cross bag were very positively evaluated. Therefore, it is confirmed that Jeju Choga could be very useful as a motif for the development of cultural products focusing on Jeju tourism souvenir market.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1310-1316
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• 2009

In this study, we investigated the change of antioxidant activity and flavonoid contents by fermentation of Citrus grandis Osbeck peel (CGP) using the Saccharomyces cerevisiae (KCCM35053), comparing to unfermented CGP. Total flavonoid content in the fermented Citrus grandis Osbeck peel (FCGP) was 3,768 g/100 g sample and higher than that of CGP. The antioxidant activities of FCGP was determined by DPPH, hydroxyl, alkyl radicals, and hydrogen peroxide scavenging assays. FCGP showed higher activities than CGP in all scavenging assays. The $IC_{50}$ values of FCGP were 261.3 ${\mu}g$/mL for DPPH; 1,474 ${\mu}g$/mL for hydroxyl; 90.9 ${\mu}g$/mL for alkyl and 1,195 ${\mu}g$/mL for $H_2O_2$ in respective scavenging assays. Flavonoid compositions of both samples were determined by liquid chromatography/mass spectrometry (LC/MS). In the spectrum FCGP was similar to CGP in the contents of neohesperidin, naringin and an unknown No. 7 compound, but some unknown compounds (No. 1, 2, 4, 5, 6) were higher than CGP in each flavonoid contents. Therefore, the fermentation of CGP could increase the contents of unknown compound and improved antioxidant activities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.420-426
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• 2018

The purpose of this paper is to examine the business cycle in the Jeju region and what differences exist in relation to the nation as a whole, to calculate the relative importance between the random walk stochastic trend and cyclical factor, and to find out its causes and implications. Results of empirical analysis found that the characteristics of the business cycle in the Jeju region were as follows: First, the Jeju region, which is likely to have a growth component of the economy such as technological development and the accumulation of capital, was projected to have a possibility of high growth due to a greater proportion of the stochastic trend factor(46.8%) than the entire country(27.8%). Secondly, employment fluctuation in Jeju, which varies from 0.007 to 0.058 depending on the model, was lowest compared to the fluctuation of other indicators. The employment market in Jeju remained firm, showing that it is not smooth enough to create new jobs despite the production growth in industry. Third, the tourism industry was acting as a stabilizing factor, whereas the mining and manufacturing production was the opposite of tourism industry. This implies that the mining and manufacturing production was based on a weak foundation.