• Korean Journal of Medicinal Crop Science
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• v.13 no.4
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• pp.171-177
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• 2005

This study was carried out to investigate the distribution and habitat feature of Glehnia littoralis as a part of establishment of conservation plan for important natural agro-plant resources in South Korea. Habitat of Glehnia littoralis was generally found 28.2 m from high tide water line and 2.7 m above sea level at sand dunes near three seashore areas. Density and coverage of Glehnia littoralis were higher in east seashore among three seashore areas. The number of plant species growing with Glehnia littoralis in natural habitat was found 35 species. Among 35 species Ixeris repens Carex pumila, Carex kobomugi, Elymus mollis, Ischaemum anthephoroides, Imperata cylindrica var. koenigii were shown higher density and coverage. Average yearly precipitation and temperature of habitat for Glehnia littoralis were 1250.3 mm and $12.5^{\circ}C$, respectively. Among three seashores, the precipitation and temperature of south seashore were much more and higher than those of other two seashores. Soil characteristics of habitat for Glehnia littoralis were that average pH was 7.9 and organic matter was 0.23%. Content $P_2O_5$ and Ca were relatively higher, but the level K and Na were very low.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.359-364
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• 2012

This study were carried out to find bolting response of cultivation in different regions and to isolate FLC (FLOWERING LOCUS C) homologs in Angelica gigas Nakai. The mean temperature of different regions, ordering in altitude, were as follows: 100 m > 350 m > 530 m > 700 m. The largest amount of rainfall was occurred in the region of 350 m while the longest time of sunshine was occurred in the region of 100 m. The content of soil chemical properties in regions showed pH 6.2 ~ 7.4, T-N 0.17 ~ 26, organic mater $1{\sim}32gkg^{-1}$, $P_2O_5$ ${151{\sim}664_{mgkg}}^{-1}$, exchangeable potassium and calcium and magnesium were 0.78 ~ 1.15, 3.9 ~ 10.0, ${0.7{\sim}3.2_{cmol}}^{+kg-1}$. L5 line of A. gigas was occurred in bolting at all regions, but the bolting ratio was 60.0% in 700 m region with non-mulching treatment. Manchu of A. gigas was not occurred in bolting at all regions. The accumulation bolting ratio of L5 line by non-mulching was higher than that of mulching as 90.4% and 72.8% in 100 m region. The MADS-box transcription factor FLC is one of the well-known examples as a strong floral repressor. We decided to isolate FLC homologs from A. gigas as a starting point of flowering mechanism research of this plant. We have isolated two RT-PCR products which showed very high amino acid sequence homology to Arabidopsis FLC.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2648-2656
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• 2011

A simple HPLC-DAD method was developed and validated to determine B group vitamin content (thiamine, riboflavin, nicotinamide, pantothenic acid, pyridoxine and folic acid) in supplemented food samples, i.e., infant formula, cereal, low-calorie food, a multi-vitamin pill and a vitamin drink. In this study, the most significant advantages were simultaneous determination of the six B group vitamins in various food matrices and a small number of sample treatment steps that required only an organic solvent, acetonitrile. Moreover, this method prevents reduction of column durability, because the mobile phase does not contain ion-pairing reagents. Analytes were separated on a Develosil RPAQUEOUS $C_{30}$ (4.6 mm ${\times}$ 250 mm, 5 ${\mu}M$ particle size) column with a gradient elution of acetonitrile and 20 mM phosphate buffer (pH 3.0) at a flow rate between 0.8 and 1.0 mL/min. Detection was performed at 275 nm, except for that of pantothenic acid (205 nm). The calibration curves for all six vitamins showed good linearity with correlation coefficients ($r^2$) higher than 0.995. The developed method was validated with respect to linearity, intra- and inter-day accuracy and precision, limit of quantification (LOQ), recovery and stability. The method showed good precision and accuracy, with intra- and inter-assay coefficients of variation less than 15% at all concentrations. The recovery was carried out according to the standard addition procedure, with yields ranging from 89.8 to 104.4%. This method was successfully applied to the determination of vitamin B groups in supplemented food products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.671-675
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• 2008

Based on information about the major microbial composition of kimchi and its relation to the taste, Leuconostoc mesenteroides K2M5 and Lactobacillus sakei K5M3 were selected as kimchi starter candidates. These two strains were found to be safe for industrial use because they showed neither harmful characteristics like ${\beta}$-hemolysis, ammonia and indole formation, and gelatin liquefaction, nor enzymatic activities like phenylalanine deaminase, ${\beta}$-glucuronidase, ${\beta}$-glucosidase, 7${\alpha}$-dehydroxylase and nitroreductase. Starter kimchi made with these strains were better in taste than the conventional kimchi when they are evaluated both by laboratory personnel and the public. Also microbial analysis of starter kimchi showed only starter bacteria after they were fermented to have the optimum acidity. Starter kimchi prepared with these two strains were not much different in physicochemical properties to the conventional kimchi except in that the starter kimchi were much higher in volatile organic acid content such as lactic acid. These results suggest that kimchi quality can be controlled to have consistent properties, both in taste and microbial composition, by using bacterial starters.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.160-166
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• 1989

This study was conducted to investigate whether egg-shell may be used as a mineral sourceor leavening agent in breadmaking. In Korea the waste volume of egg shell has been estimated at about 28,694 tons per year. Carbon dioxide generation maxima were established for barking powder$(153{\pm}3ml/g)$, egg-shell(205in reaction with lactic acid) and yeast$(115{\pm}3ml/sugar\;g)$. Gas release time required for each substance to reach $CO_2$ maximum was, for baking powder 7 minutes, for egg-shell 45 mins and for yeast 240 mins. Particle size of egg-shell in breadmaking was suitable more than 20 mesh (-). When egg-shell only was added to the basic formular without including lactic acid, no leavening effect was observed. However, when lactic acid and egg-shell were used together, the leavening effect was more or less equivalent to that of yeast(control). Addition of egg-shell was found to increase calcium content of bread products without noticeable altering flavor, as compared with control. Joint use of egg-shell was organic acids in breadmaking was shown to have potential in time saving, volume increase and yeast saving.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.155-159
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• 2016

The objective of this study was to investigate the effect of fermentation temperature on quality characteristics of apple wine. Apple wine mashes were fermented in 15, 20, and $25^{\circ}C$ water bathes for 9 days. The pH levels of all samples were below 4 from 24 h of fermentation until the end. Total acidities of 0.05% acetic acid solution were 7.8, 7.4, and 7.0% in the 15, 20, and $25^{\circ}C$ fermented samples, respectively. The evaporation of esters generated by combining alcohol and organic acids might be the reason for lower total acidity for high temperature fermentation. Alcohol contents of the 20 and $25^{\circ}C$ fermented samples were 6.5 and 6.6% (v/v), respectively, whereas that of the $15^{\circ}C$ fermented sample was 5.6% (v/v) and significantly lower than the others (P<0.05). Methanol contents were 0.68, 0.82, and 1.69 mg/L in the 15, 20, and $25^{\circ}C$ fermented samples, respectively. Fermentation at higher temperatures generated higher methanol content in apple wine. On the other hand, acetaldehyde contents were 3.43, 2.39, and 1.02 mg/L in the 15, 20, and $25^{\circ}C$ fermented samples, respectively, due to the lower boiling point of acetaldehyde ($20.2^{\circ}C$). Based on the results, a fermentation temperature of $20{\sim}25^{\circ}C$ is effective for apple wine fermentation.

• Journal of the Korea Concrete Institute
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• v.28 no.3
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• pp.309-316
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• 2016

In this study, performance of hardening accelerator types which promote setting and hardening of cement has been reviewed in order to develop early age strength of concrete with compressive strength of 21~27 MPa after examination of strength development of the concrete at early age according to curing temperature and unit cement(binder) content. As results, soluble mineral salt showed better hardening acceleration effect than organic salt in the scope of this study. Also, hydration reaction accelerating effect of $C_3S$ by Soluble mineral salt is effective on development of early age compressive strength and it was shown that the Pt's hydration reaction accelerating effect was the best. Construction duration reduction can be expected by securing compressive strength for prevention of early aged freezing damage in 25hour-curing time under curing temperature at $15^{\circ}C$. Also, it was shown that compressive strength of specimen cured at $5^{\circ}C$ was similar with plain specimen cured at $10^{\circ}C$. Therefore, it is expected that fuel costs and carbon dioxide can be reduced when the same construction duration is considered.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.405-415
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• 2006

Sixteen soil samples around six areas (residental area, traffic area, power plant area, incineration area and factory area) where the stationary and mobile sources of polycyclic aromatic hydrocarbons (PAHs) are estimated to be emitted in Jeju City, were collected during Feburuary to March, 2004, and analyzed for 16 PAHs recommended by US EPA as primary pollutants to investigate their distribution characteristics. The concentrations of total PAHs (t-PAHs) and total carcinogenic PAHs $(t-PAH_{CARC})$ in soils of Jeju City were in the range of $21.7\sim264.2ng/g$ on a dry weight basis with a mean value of 87.2 ng/g and $6.3\sim118.0ng/g$ with a mean value of 33.4 ng/g, respectively. The concentrations of t-PAHs were low in comparison with those in soils of other domestic and foreign countries. The mean concentrations of t-PAHs and $(t-PAH_{CARC})$ with area decreased in the following sequences: traffic area> incineration area > factory area > power generation area > harbor area enli residental area. The correlation between t-PAHs and $(t-PAH_{CARC})$ were very high $(\gamma^2=0.9701)$, indicating that $(t-PAH_{CARC})$ concentration increases in proportion with t-PAHs. Comparing the distribution ratio of ring PAHs with area among 16 PAHs, it decreased in the order of 4-ring > 5-ring > 6-ring > 3-ring > 2-ring in all the areas except for harbor area. whitens for harbor area it was similar among 3-, 4- and 5-ring with high value. Low and no correlations between t-PAHs and soil compositions (organic matter content and particle size distribution) were observed, which is considered to be caused by the complex factors, such as the loading and characteristics of PAHs and diverse soil environment change, etc. From the examination of the three PAH origin indices, such as LMW/HMW (low molecular weight $2\sim3$ ring PAHs over high molecular weight $4\sim6$ ring PAHs), phenanthrene/anthracene ratio and fluoranthene/pyrene ratio, it can be concluded that the soil PAH contaminations were ascribed to strong pyrogenic origin in ail areas except for harbor area and to both pyrogenic and petrogenic origins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.143-148
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• 2012

This study evaluated the quality characteristics of white birch (Betula platyphylla var. japonica) sap with different collection times. The changes of browning index, turbidity, pH, total acidity, organic acid, free sugar, crude protein, crude ash, and mineral content were investigated. The browning index and turbidity increased from 0.076 to 0.222 and from 0.048 to 0.138, respectively, with increasing collection time. The pH decreased from 6.09 to 4.72, while total acidity increased with increasing collection time. Citric and malic acids were detected and malic acid increased with increasing collection time. Glucose and fructose as free sugars were detected and their contents were 0.364~0.433% and 0.497~0.664%, respectively. Crude protein and crude ash contents remarkably increased from 3.40 to 32.37 mg% and from 0.01% to 0.04%, respectively, with increasing collection time. Cu, Fe, Ca, Mg, Mn, and K were detected, and increased with increasing collection time. Particularly, K increased remarkably from 5.25 to 37.27 mg/L over time. These results indicate that the optimum processing method to improve the quality of white birch sap is necessary, because the quality of sap decreased as collection time increased, but nutritional value increased.

• Journal of Bio-Environment Control
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• v.12 no.4
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• pp.184-189
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• 2003

This research was conducted to determine the effect of mixing ratio of aquafarm waste water sludge (AWWS) in the growing medium as a source of fertilizers on growth of plug seedlings of pepper (Capsicum annuum L.) and tomato (Lycopersicum esculentum Mill.). Increased mixing ratio of AWWS resulted in increased fresh and dry weights, leaf area, plant height, and total chlorophyll content, although there were slight differences in growth characteristics at 20 and 40 days after sowing. Concentration of AWWS affected insignificantly the percent dry matter, number of leaves, and length of the longest root. The addition of AWWS increased pH and decreased EC in the medium as compared to that of chemical fertilizer. Compared to the control of a liquid fertilizer, 4 or 8 kg AWWS${\cdot}45L^{-1}$ medium (Sludge 4) gave a similar or slightly better growth. Above results suggested that addition of about 4 kg AWWS${\cdot}45L^{-1}$medium is sufficient for seedling growth and the AWWS can be used as a substitute for the liquid fertilizer in plug seedling production.