• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.151-160
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• 1998

Tangerine peel is mostly discarded as waste in citrus processing. However, tangerine peel contains besides dietary fibers bioflavonoids such as naringin and hesperidin which act as antimicrobials and blood pressure depressants, respectively. A continuous membrane separation process was optimized for the production of bioflavonoids relative to feed flow rate, transmembrane pressure, temperature, and pH. The tangerine peel was blended with 7.5 times water volume and the extract was prefiltered through a prefiltration system. The prefiltered extract was ultrafiltered in a hollow fiber membrane system. The flux and feed flow rate didn't show any apparent correlation, but we could observe a mass-transfer controlled region of over 8 psi. When temperature increased from $9^{\circ}C\;to\;25^{\circ}C$, the flux increased about $10\;liters/m^2/min\;(LMH)$ but between $25^{\circ}C\;and\;33^{\circ}C$, the flux increased only 2 LMH. At every transmembrane pressure, the flux of pH 4.8 was the most highest and the flux at pH 3.0 was lower than that of pH 6.0, 7.0, or 9.0. Therefore, the optimum operating conditions were 49.3 L/hr. 10 psi, $25^{\circ}C$, and pH 4.8. Under the optimum conditions, the flux gradually decreased and finally reached a steady-state after 1 hr 50 min. The amount of dietary fibers in 1.0 g retentate in each separation step was analyzed and bioflavonoids concentration in each permeate was measured. The contents of total dietary fiber in the 170 mesh retentate and soluble dietary fiber in the prefiltered retentate were the highest. Naringin and hesperidin concentration in the permeate were $0.45{\sim}0.65\;mg/g\;and\;5.15{\sim}6.86\;mg/g$ respectively, being $15{\sim}22$ times and $79{\sim}93$ times higher than those in the tangerine peel. Therefore, it can be said that PM 10 hollow fiber membrane separation system may be a very effective method for the recovery of bioflavonoids from tangerine peel.

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.38-58
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• 2013

The existence of endemism in many parts of the world is an important factor for conservationists. Conservation can only be carried out under national legislation, and national endemics, which have very limited ranges, fully depend on the effort and success of conservation. A total of 523 vascular plant taxa were listed in the latest national checklist by Ministry of Environment in 2005, while the 'Creation and Furtherance of Arboretums Act' including a national endemic list (appendix 4-1) was established by Korea Forest Service and was legislated as a law in late 2011. This legislation by Korea Forest Service on endemism of Korean vascular plants have required much attention because of discrepancies of nomenclature, taxonomic bias and inflation. Examining data for both lists proposed by Ministry of Environment and Korea Forest Service, of the total of 360 legislated taxa, around 286 taxa are shared with the list of Ministry of Environment, of which about 80% have been found as common taxa. Around 67(18.7%) are typographic errors, and 14 taxa (3.9%) are recorded as illegitimate and invalidly published names. Through this analysis 12 taxa (3.4%) were found in China as well as in Korea and these are thought to be non Korean endemic taxa. Taken together, the legislated list displayed 1/4 (24.9%) errors out of the total list. Only 59 taxa (16.5%) are identified as national endemic species. The remainder are either unresolved candidates (73 taxa, 20.4%) or synonyms (196 taxa, 54.7%) status. It must be noted, that the concept of endemism very much depends on the knowledge of the species concept, taxonomic bias and geographical range of a species. Also, the most major nomenclatural problem tend to be more stable if the information on database about Korea Plant Name, which is managed by Korea National Arboretum are well updated year to year. These exaggerated numbers underscore the urgency for regional conservation planning and implementing effective strategies to preserve these real endemic taxa into the future.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.1-12
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• 2016

This study was carried out for the improvement of nutrition and quality of streamed bread. For this purpose, brown rice liquid starter and brown rice sourdough were made and steamed bread was made with different amounts of starter addition followed by a measurement of its physicochemical and sensory characteristics. The pH of dough and titratable acidity tended to decrease significantly according to brown rice sourdough. In addition, the titratable acidity of the control group had significant different by samples. As for the volume of dough, there was no significant difference between the control sample and each sample, but after 15 minutes of fermentation, the volume increased the most in the control sample, with sample D having the least volume. As for volume and specific volume of steamed bread, sample B had the largest at 3.34 and each sample had significant differences based on fermentation time. As for diameter, sample B was the largest at 88.11 and sample D was the smallest at 79.04, with significant differences among samples. As for height of steamed bread, the control group was the highest at 42.91 and sample D was the lowest at41.87, with significant differences among samples. As for the cross-section structure of steamed bread, the porous of sample B, which had the largest volume and specific volume, was the largest with uniform texture and even distribution. L value tended to be higher in the added sampleroups than in the control sample. a value increased as brown rice sourdough increased, and b value was lower when volume and specific volume of the steamed bread increased, which showed a similar trend with that a L value. As for hardness, viscosity, and chewing capacity, sample D was the highest and sample B was the lowest, with significant differences among samples. As a result of measurement of overall preference, sample B had the highest preference with the highest preference in flavor, taste, appearance and texture, and D had the lowest preference with the lowest preference in taste, appearance and texture, with significant differences among samples.

• KDI Journal of Economic Policy
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• v.32 no.2
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• pp.55-92
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• 2010

In terms of labor market accomplishments, such as income, size of the company, and the matching quality between one's job and college major (specialization), a very large discrepancy is observed between the graduates from colleges located in Seoul and those outside Seoul. But, when the department average score of the Scholastic Aptitude Test (SAT) at the time of college entrance is controlled for, the discrepancy is found to be reduced to a considerable degree. In the case of wage gap, at least two third can be explained by the SAT score gap. The remaining wage gap seems to reflect the characteristics of workplace. In other words, graduates with high SAT scores enter colleges located in Seoul and thus tend to find better jobs leading to earning differences. This result that confirms the importance of aptitude test scores suggests that in the labor market, one of the major reasons behind a lower accomplishment of the graduate from local colleges is due to a lower competitiveness of local colleges in attracting the brightest students. But, this should not be viewed as only an internal problem of local colleges. This is because the growth of local economies tends to haul the advancement of local colleges in that area rather than being the other way around. The agglomeration effect in Seoul where headquarters of large corporations and financial institutions gather is the factor that has elevated the status of colleges located in Seoul since this provides highly preferred job choices of graduates. When the competitiveness of college is significantly influenced by exogenous factors, such as the vicinity to Seoul, the effort being made by colleges alone would not be enough to improve the situation. However, the central government, too, is not in the position to carry out countermeasure policies for such problems. The regional development strategy boosted through supportive policies for local colleges, such as financial support, is not based on the persuasive and empirical grounds. It is true that college education is universal and that the government''s intervention in assisting local colleges to secure basic conditions, such as tenure faculty and adequate facilities is necessary. However, the way of intervention should not be a support-only type. In order to improve the efficiency and effect of financial support, restructuring programs, including the merger and integration of insolvent colleges, should be underway prior to providing support. In addition, when the policy is focused on education recipients-local college students, and not on education providers-local colleges, the importance of regional gap in compulsory education (elementary and junior high schools) turns out to be much important as the gap between metropolitan area colleges and local colleges. Considering the educational gap before college entrance shown from the discrepancies of aptitude test scores among different regions, the imbalance between regions in terms of human resources is apparently derived from compulsory education, and not from college education. Therefore, there is a need to double the policy efforts to reduce the educational gap among different regions. In addition, given the current situation where it is difficult to find appropriate ex post facto policy measures to solve the problem of income gap between the graduates from metropolitan colleges and local colleges, it can be said that improving the environment for compulsory education in local areas is a growing necessity for bridging the educational gap among different regions.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.1
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• pp.44-52
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• 2018

This experiment was conducted at Suwon, Korea from 2013 to 2015. The objective of this study was to establish the optimum seeding rate, and to clarify the nitrogen fertilizer level for rye seed production in central and north area of Korea. We used Korean rye cultivar 'Gogu' for this test. We employed a split-plot design with three replications. The main plots were designed by three seeding levels (3, 5 and $7kg\;10a^{-1}$), but other sub-plots were randomly seeded. The plots were treated with three different nitrogen fertilizer levels (3, 6 and $9kg\;10a^{-1}$). The percentage of productive tiller, number of grain per spike, fertility rate, 1 liter weight, and 1000-grain weight decreased as seeding rate increased from $3kg\;10a^{-1}$ to $7kg\;10a^{-1}$, whereas the number of spike per $m^2$ increased. Therefore the grain yields of rye had less of an effect by increasing seeding rate. There was an increase in number of spike per $m^2$, number of grain per spike, and fertility rate as nitrogen fertilizer level increased from $3kg\;10a^{-1}$ to $9kg\;10a^{-1}$, but grain yields significantly not affected by the interaction of seeding rate ${\times}$ nitrogen fertilizer levels. However, the best seeding rate and nitrogen fertilizer level for rye seed production were 5 kg and $5{\sim}6kg\;10a^{-1}$, respectively, considering seed and fertilizer reduction and the prevention of pollution by excess fertilization.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.12
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• pp.664-671
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• 2017

Non-point source pollution is the emission source that unspecifically releases pollutants to water system from unspecific places such as cities, agricultural lands, mountains, and construction sites and its discharge path is not easily identified. Also, it is difficult to design and manage the reduction facilities for the emission quantity is primarily affected from weather conditions like rainfall. Since 2006, the significance of non-point source pollution reduction has been grown in Republic of Korea and this reinforces needs for the installation of reduction facilities. However, because the standards for the installation details and reduction efficiency are not clarified by law, people are preferring technologies that do not require particular maintenance and high expenses. The purpose of this study is to examine and maintain the efficiency of non-point source pollutants reduction facility which uses expended polypropylene as a media. The higher the depth of the media, the less range of variations in the reduction efficiency was observed and the final efficiency was also increased. When the media depth was 60 cm, the average reduction efficiency was 94% and 90% where linear velocities were 10 m/hr and 20 m/hr respectively. The results from 180 minutes operation in 10 m/hr and 20 m/hr of linear velocities were slightly different in head loss changes which were caused by media depth variations. The backwash experiments which were conducted in triplicate showed the reduction efficiency decreased as the time went on because of the media clogging. However, it was found that after the backwashing the reduction efficiency was increased as effective as the efficiency of the initial filtration.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.202-218
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• 1976

In this experiment American Summer Pairman apple was selected as test fruit in order to study the effect of sub-atmospheric pressure storage in the apple. keeping a certain pressure condition, a new sub-atmospheric pressure system was designed and constructed in which fruits were stored at $25^{\circ}C$ under two different atmospheric pressure conditions such as Normal Atmospheric Pressure (NAP) and Sub-Atmospheric Pressure (SAP). Moreover, they were divided into plots of 5% and 0% of $CO_2$, on the basis of gas composition. Under these conditions, the amount of respiration and ethylene evolution, and the changes of intercellular gas composition and organic components were investigated throughout the storage. The results obtained are as follows: (1) The intercellular gas was exhausted so rapidly by the SAP treatment that the gas equilibrium in the tissues reached within 5 minutes. (2) The amount of respiration was found to be higher in plots of NAP than SAP, and under the conditions, controlling $CO_2$ content, plots of $CO_2$ 5% were lower in the amount of respiration than $CO_2$ 0%. The climateric rise was revealed more slowly in plots of the SAP than NAP. These results indicate that the SAP treatment was an efficient method for controlling the respiration of fruits. Furthermore, these results were also realized with the results of the respiratory quotient (R.Q) and intercellular gas composition. (3) Evolution of ethylene, the ripening hormone in plant, was shown the similar tendency to the climacteric pattern of respiration; at the stage of climacteric maximum, the maximun amount of ethylene was found earlier in plots of NAP than SAP, and post climacteric stage was prolonged in the plots of the SAP compared to those of the NAP. The ethylene concentration in tissue appeared lower in plots of the SAP than NAP, which might suggest that the SAP treatment was caused to restriction of ethylene evolution. (4) Effects of the SAP treatment mentioned hitherto were proved also with the test of the external appearance such as changes of color and freshness, firmness, rotting and weight loss. (5) In the investigation of organic components, vitamin C and organic acids varied less in plots of SAP than NAP. Specially, it was remarkable that the loss of malic acid was least decreased by the SAP treatment. These effects of the SAP treatment were distinctive in the changes of the ratios of malic and citric acid to total acid, and the ratios of free sugar to free acid.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.219-226
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• 1976

To meet the need of protein feed and fine more efficient ways of returning waste to resources, we have carried out the study of the production of yeast for foods and feeds from the corn starch cake. The present study includes the method for acid-hydrolysis, the selection of yeast capable of utilizing hydrolyzate of the corn starch cake, and culture condition of Candida tropicalis under the liquid culture and the semisolid culture. Obtained results were as follows. 1. Hydrochloric acid was more excellent on the hydrolysis of the corn starch cake than sulfuric acid, and the yield of sugar was maximum, 57.2%, when the corn starch cake was hydrolyzed with 1.0% of hydrochloric acid at 2.0kg/cm for 30 minutes. 2. As the acid solution content was increased, more sugar was liberatedfrom the mixture, until the acid solution-substrate ratio reached 10:1. Beyond this point, no further increase was observed. To prepare the cultural medium of semisolid fermentation, a acid solution to substrate ratio of 3:1 appeared to be optimum. 3. Out of 6 yeast strains, Candida tropicalis had excellent growth on the hydrolyzate of the corn starch cake, and optimum temperature and initial pH were $30^{\circ}C$ and 6.0 respectively. 4. Optimum liquid medium of Candida tropicalis is ures 0.3%, potassium phosphate monobasic 0.15g and magnesium sulfate 0.04g in 100ml of the hydrolyzate of the corn starch cake, while optimum semisolid medium is ammonium chloride 0.4g, potassium phosphate monobasic 0.1%, magnesium sulfate 0.04%. 5. Candida tropicalis could assimilate the sugar in the hydrolyzate up to more than 88.75%, and a yield of dry yeast reached 19.13% to the corn starch cake under the liquid culture. 6. Compared to the that of the untreated corn starch cake, the cellulose content of the semisolid fermented cake decreased by 3.76% to 14.7%, whereas dry yeast contents increased by 13.89%.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.297-305
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• 2006

This study was conducted to evaluate the quality characteristics of low-fat emulsion type sausages containing 0% tomato powder (C), 5.0% ground raw tomato paste (T1) and 0.5% freeze dried tomato powder (T2) during storage at $5{\pm}1^{\circ}C$ for 30 days. The crude protein content of T2 was significantly lower (p<0.05) than that of the other sausage types. Moisture, crude fat and crude ash contents of the sausages during storage were not affected by the addition of tomato. The pH and shear force ($kg/cm^2$) values of C were significantly higher (p<0.05) than those of T1 and T2. There was no significant difference among the different sausages in cooking loss, ranging from $13.00{\sim}14.98%$. The WHC values of T1 and T2 were significantly higher (p<0.05) than that of C. The values of TBARS were significantly (p<0.05) increased for ail sausages following storage. The TBARS value (mg MA/kg) of C was significantly higher (p<0.05) than those of T1 and T2 at 15 days of storage, however T1 was significantly higher (p<0.05) than the other sausages after 30 days of storage. The meat color values tended to decrease with increased storage time. Microorganism analysis revealed that all sausage types did not reach $4.4log_{10}CFU/g$ until 30 days of storage. The texture, brittleness, Hardness, and springiness of each sausage type were not significantly different after 1 day of storage, while the cohesiveness, gumminess and chewiness of T1 and T2 were significantly higher (p<0.05) than that of C. T1 and T2 sausages had a slightly higher score regarding color, aroma, tenderness and overall acceptability, however the sensory evaluation score among the different sausage types was not significantly different (p>0.05). In conclusion, low-fat sausage with added tomato showed higher lipid oxidative stability during storage than sausage to which no tomato was added.

• Microbiology and Biotechnology Letters
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• v.38 no.4
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• pp.420-427
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• 2010

A process for manufacturing virally-safe bovine amniotic membrane(BAM) has been developed for biological dressing. BAM was harvested from a healthy bovine placenta, and then the epithelium was removed. The remaining stromal layer was consecutively disinfected with 70% ethanol and 0.05% sodium hypochlorite. The stromal layer was incubated in a decellularization solution containing 0.25%(w/v) trypsin to remove the cellular components. The resulting acelluar BAM was lyophilized to preserve its biochemical and structural integrity. The BAM was packed and exposed to 25 kGy of gamma irradiation for sterilization purpose. Histological, electron microscopical, and biochemical observations showed that the acellualr BAM had intact structural integrity of three dimensional collagen fibers and contained several growth factors, accelerating wound healing, such as EGF (Epidermal growth factor), KGF (Keratinocyte growth factor), and FGF (Fibroblast growth factor). Bovine herpes virus (BHV), bovine viral diarrhoea virus (BVDV), bovine parainfluenza virus type 3 (BPIV-3), and bovine parvovirus (BPV) were chosen as the biological indicators for validation of viral safety of the acellular BAM. Samples from relevant stages of the production process were spiked with each virus and subjected to viral inactivation processes. Viruses were recovered from the samples and then titrated immediately. All the viruses tested were completely inactivated to undetectable levels within 1 h of 70% ethanol treatment. Enveloped viruses such as BHV, BVDV, and BPIV-3 were more effectively inactivated than BPV by 0.05% sodium hypochlorite treatment. BHV, BVDV, and BPIV-3 were completely inactivated to undetectable levels by 25 kGy of gamma irradiation. Also BPV was effectively inactivated by 25 kGy of gamma irradiation. The cumulative log reduction factors of BHV, BVDV, BPIV-3, and BPV were ${\geq}$13.30, ${\geq}$14.32, ${\geq}$15.22, and ${\geq}$7.57, respectively. These results indicate that the production process for acelluar BAM has a sufficient virus-reducing capacity to achieve a high margin of the virus safety.