• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.5
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• pp.767-774
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• 2015

In recent decades, health concerns related to sodium intake have caused an increased demand for salt or sodium-reduced foods. Umami substance can enhance taste sensitivity to NaCl and may offer a unique approach to replace and reduce the sodium content in foods. In this study, hot water extraction conditions of Wando sea tangle with high umami taste were investigated. Wando sea tangle harvested in June was selected for hot water extraction based on its free amino acids composition. The quality properties of sea tangle extract were investigated at various extraction temperatures ($60^{\circ}C$, $80^{\circ}C$, and $100^{\circ}C$) and times (1 h, 2 h, and 3 h). Sea tangle extracts at the extraction temperature of $100^{\circ}C$ contained the highest soluble solids (35.47%~36.93%), and crude protein (3.75%~4.00%). Viscosities of sea tangle extracts decreased with increasing extraction temperature. Umami amino acids (glutamic acid and aspartic acid) and sensory characteristics were best at extraction conditions of $100^{\circ}C$ for 2 h. Saltiness enhancement of sea tangle extract powder was determined. Saltiness intensities of NaCl solution after adding 1% sea tangle extract powder were enhanced (1.84~4.25-fold). At the same saltiness intensity, sodium contents of NaCl solution with 1% sea tangle extract powder were 12.24~24.33% lower than that of NaCl solution. These results suggest that it is possible to reduce sodium in foods with sea tangle extract as a natural salt enhancer without lowering overall taste intensity.

• Korean Journal of Food Science and Technology
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• v.17 no.2
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• pp.65-70
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• 1985

To recover proteins from antarctic krill(Euphausia superba) for the use of food material, some factors affecting the extraction of protein were investigated. The protein solubility profile showed a minimum solubility level(33.2-38.8%) within the range of pH4.0-4.5 and very high solubility levels as 56.8% at pH2.0 and 80.7% at pH11.0. The extraction yield increased as the solvent-to-krill ratios increase in which a ratio of 5:1(volume of solvent/weight of krill) was found to be preferable from the point of handling convenience and extraction yield. The extraction temperatures did not seem to be important variables on extraction of protein. The extraction of krill protein occurred fairly rapidly with little further extraction of protein after 30 minutes. The extraction of protein was slightly decreased at both acidic(pH2.0) and alkaline(pH11.0) conditions with the increasing concentration of sodium chloride. The extractibility of krill protein at strong alkaline condition(pH11.0) was higher than at strong acidic condition(pH2.0) under the same concentration range as 1-6% of sodium chloride. In phosphate treatments, the extraction of protein was slightly influenced by presence of sodium chloride as the concentration range of 3-4% in the aqueous solvent by which maximize the extraction yield as over 80%.

• Journal of Food Hygiene and Safety
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• v.32 no.4
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• pp.329-335
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• 2017

Analysis method was presented for the simultaneous determination of nine bisphenol A related compounds such as bisphenol A (BPA), phenol, p-tert-butylphenol, bisphenol A diglycidyl ether (BADGE), $BADGE{\cdot}2H_2O$, $BADGE{\cdot}2HCl$, bisphenol F diglycidyl ether (BFDGE), $BFDGE{\cdot}2H_2O$ and $BFDGE{\cdot}2HCl$ migrated from inner coatings of metal food cans by high performance liquid chromatography (HPLC) with fluorescence detection. The method was validated by examining the linearity of calibration curve, the limit of detection (LOD), the limit of quantification (LOQ), recovery and uncertainty. The migration tests of nine BPA related compounds were carried out with four food simulants; deionized water (DW), 4% acetic acid, 50% ethanol and n-heptane. There was not any compound detected in DW, 4% acetic acid and 50% ethanol at $60^{\circ}C$ for 30 min and n-heptane at $25^{\circ}C$ for 60 min. BPA and phenol were migrated into 4% acetic acid and 50% ethanol at $95^{\circ}C$ for 30 min. The concentrations were ranged from 0 to $10.77{\mu}g/L$ of BPA and from 0 to $2.35{\mu}g/L$ of phenol. Canned foodstuffs mostly have long-term shelf life. We investigated migration of nine BPA related compounds according to the variation in storage periods (0~90 days) and temperatures (4, 25 and $60^{\circ}C$). All compounds were not founded during 90 days at $4^{\circ}C$ and $25^{\circ}C$, respectively. However BPA and $BADGE{\cdot}2H_2O$ were founded in DW and 4% acetic acid at $60^{\circ}C$. The migration levels of BPA and $BADGE{\cdot}2H_2O$ were close to the value of LOQ, respectively and did not change significantly as storage period. It was founded from results that the migration of BPA related compounds from metal food cans was controlled to a safe level.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.390-399
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• 2014

The objective of this study was to establish a processing technology for preserved leaves based on the results from the examination of the optimal period and condition for dye-absorbing treatment for Eucalyptus cinerea F. Mull. ex Benth. (silver dollar eucalyptus) being used frequently as plant material for flower design. Cut foliages of E. cinerea with uniformly matured leaves were cut into 20 cm lengths and their lower stem parts were placed in dye solution in growth chambers with different temperatures (10, 20, 30, and $40^{\circ}C$), vapor pressure deficits (VPD; 0.23, 0.70, 1.17, and 1.61 kPa), and photoperiods (0, 6, 12, 24 hours) for 3, 6, 9, and 12 days, and then dried in a room of $20^{\circ}C$ for three days. Lower temperature during preserving dye treatment reduced the changes in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Especially, high temperature increased red degree (a) and decreased yellow degree (b) due to browning. Lower VPD reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. Shorter photoperiod reduced the change in leaf color compared with fresh leaves and decreased ${\Delta}E$ value. The ${\Delta}E$ value increased with increasing absorbing duration under three environmental conditions. The flexibility of stem and leaves after dipped into preserving dye solution and dried for 3 days increased with decreasing temperature, VPD and dipping duration. Therefore, the optimal environment condition for dye treatment was 0.23-0.70 kPa VPD at $10-20^{\circ}C$ in the darkness, and the optimal and economical duration was 3 days. These conditions reduced the speed of water loss by decreasing transpiration, so yellowing or browning by rapid water loss deteriorated the quality of preserved leaves out of these ranges.

• Korean Journal of Ecology and Environment
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• v.44 no.1
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• pp.31-41
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• 2011

To optimize the natural chemical agents against nuisance phytoplankton, we examined algal removal activity (ABA) of Plant-Mineral Composite (PMC), which already developed by our teams (Kim et al., 2010), on various conditions. The PMC are consisted of extracted-mixtures with indigenous plants (Camellia sinensis, Quercusacutissima and Castanea crenata) and minerals (Loess, Quartz porphyry, and natural zeolite), and characterized by coagulation and floating of low-density suspended solids. A simple extraction process was adopted, such as drying and grinding of raw material, water-extraction by high temperature-sonication and filtering. All tests were performed in 3 L plastic chambers varying conditions; six different concentrations ($0{\sim}1.0\;mL\;L^{-1}$), six light intensities ($8{\sim}1,400\;{\mu}mol\;m^{-2}s^{-1}$), three temperatures ($10{\sim}30^{\circ}C$), four pHs (7~10), five water depths (10~50 cm), and three different waters dominated by cyanobacteria, diatom, and green algae, respectively. Results indicate that the highest ABA of PMC was seen at $0.05\;mL\;L^{-1}$ in treatment concentrations, where showed a reduction of more than 80% of control phytoplankton biomass, while $1,400\;{\mu}mol\;m^{-2}s^{-1}$ in light intensity (>90%), $20{\sim}30^{\circ}C$ temperature (>60%), 7~9 in pH (>90%), below 50 cm in water depth (>90%), and cyanobacterial dominating waters (>80%), respectively. Over the test, ABA of PMC were more obvious on the algal biomass (chlorophyll-${\alpha}$) than suspended solids, suggesting a selectivity of PMC to particle size or natures. These results suggest that PMC agents can play an important role as natural agents to remove the nuisant algal aggregates or seston of eutrophic lake, where occur cyanobacterial bloom in a shallow shore of lake during warm season.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.1
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• pp.28-34
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• 2017

A new naked oat cultivar, 'Jungmo2005'(Avena nuda L.), was developed for food and forage use by National Institute of Crop Science, RDA in 2010. It was derived from a cross between $F_1$['Early80'/'Gwiri33'] and $F_1$['Early80'/'Gwiri23']. 'Early80', a covered oats, has early heading and high yielding, while 'Gwiri23' of covered type and 'Gwiri33' of naked type has early heading with large-size grain. 'Jungmo2005' has the characteristics of narrow and long leaves of pale green color, middle diameter culm of yellow color and medium grain of whitish yellow color. Cultivar 'Jungmo2005' had 2 days earlier heading date (May 9) than the check cultivar 'Seonyang' (May 11) in field condition. The 'Jungmo2005' showed better winter hardiness than that of the check cultivar, and similar to the check cultivar in respect to lodging resistance. The 'Jungmo2005' had 105 cm of culm length, 21.5 cm of spike length, 658 spikes per $m^2$, 82 grains per spike, 23.3 g of 1,000-grain weight, and 622 g of test weight. The grain yield of 'Jungmo2005' was averaged $3.38MT\;ha^{-1}$, which was 6% higher than that of the check. Average forage fresh and dry matter yield of 'Jungmo2005' harvested at milk-ripe stage were 44.8 and $12.6tone\;ha^{-1}$, respectively, compared with 47.5 and $12.5tone\;ha^{-1}$ of the check. The protein content of the 'Jungmo2005' was similar to the check (7.6% and 7.5%, respectively), while ADF (28.6%) and NDF (51.5%) were lower than the check (31.4% and 57.0%, respectively). TDN content and RFV were higher than those of the check (66.3%, 120.3 and 64.1, 105.2, respectively). 'Jungmo2005' is recommended for fall sowing cropping only in the south area where daily minimum mean temperatures are averaged higher than $-4^{\circ}C$ in January, and it should not be cultivated in mountain areas, where frost damages is likely to occur. The areas would do better only to sow in spring season.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.125-131
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• 2017

'Saeyoung', a winter triticale (X Triticosecale Wittmack) for forage, was developed at the Department of Rice and Winter Cereal Crop, NICS, RDA in 2012. The cultivar 'Saeyoung' has narrow and long leaves of light green color, middle size and thin culm, and a medium grain of brown color. The heading date and yellow ripe stage of 'Saeyoung' was May 3 and May 27, which were similar to check cultivar 'Shinyoung', respectively. 'Saeyoung' showed a little stronger in cold tolerance and a little weaker in resistance to lodging than the check, and wet injury, powdery mildew, and leaf rust were similar to those of the check cultivar. The forage fresh and dry matter yields of 'Saeyoung' at milk-ripe stages were 47.2 and $15.6MT\;ha^{-1}$, respectively, which was 9% and 4% higher than those of the check. The crude protein content of 'Saeyoung' was 0.4% lower than 6.8% of the check, while was higher than the check cultivar 'Shinyoung' in neutral detergent fiber, acid detergent fiber. Total digestible nutrients of 'Saeyoung' was also 3% lower than 62.8% of the check cultivar. It showed grain yield of $4.1MT\;ha^{-1}$, which was 11% higher than that of the check. 'Saeyoung' is recommended for fall sowing forage crops in areas in which average daily minimum mean temperatures in January are higher than $-10^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.613-619
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• 2010

Three varieties of taro flours (Altoran, Josaengjong, and Jaeraejong) were analyzed to evaluate their nutrient composition and physicochemical properties. Moisture contents of the three taro cultivars varied from 5.74-10.30%. Among the three cultivars, Altoran flour had higher protein and fat contents than other cultivars. There were 17 kinds of amino acids in the three taro flours. The major fatty acids in the three taro flours were linoleic acid (46.5-51.4%), palmitic acid (21.7-25.8%), and oleic acid (12.3-18.7%), and two thirds of the total fatty acids were unsaturated fatty acids. Potassium, phosphorus, magnesium, and calcium were the most plentiful minerals in the three taro flours, and the free sugars were glucose, fructose, and sucrose. The total dietary fiber contents of the three taro flours ranged from 12.97 to 17.60%. From these results, Altoran contained a high level of dietary fiber, minerals, essential amino acids, and free sugars. Jaeraejong showed the highest water absorption index. The water soluble index of Altoran was higher than that of the other cultivars. From the differential scanning calorimeter results, the gelatinization temperatures of the three taro flours were $84.98-89.91^{\circ}C$. The pasting temperature of the three taro flours was from 46.77 to $49.30^{\circ}C$ by rapid visco-analyzer. Among these varieties, Josaengjong had the highest peak viscosity and final viscosity, whereas Altoran had the lowest. These taro cultivars are expected to be potential material for application in taro processed foods, due to their gelatination and pasting properties.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.517-535
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• 2007

Two distinctive Mesozoic hydrothermal systems occurred in South Korea: the Jurassic/Early Cretaceous(ca. $200{\sim}130$ Ma) deep-level ones during the Daebo orogeny and the Late Cretaceous/Tertiary(ca. $110{\sim}45$ Ma) shallow hydrothermal ones during the Bulgugsa event. The Mesozoic hydrothermal system and the metallic mineralization in the Korean Peninsula document a close spatial and temporal relationship with syn- to post-tectonic magmatism. The calculated ${\delta}^{18}O_{H2O}$ values of the ore-forming fluids from the Mesozoic metallic mineral deposits show limited range for the Jurassic ones but variable range for the Late Cretaceous ones. The orogenic mineral deposits were formed at relatively high temperatures and deep-crustal levels. The mineralizing fluids that were responsible for the formation of theses deposits are characterized by the reasonably homogeneous and similar ranges of ${\delta}^{18}O_{H2O}$ values. This implies that the ore-forming fluids were principally derived from spatially associated Jurassic granitoids and related pegmatite. On the contrary, the Late Cretaceous ferroalloy, base-metal and precious-metal deposits in the Taebaeksan, Okcheon and Gyeongsang basins occurred as vein, replacement, breccia-pipe, porphyry-style and skarn deposits. Diverse mineralization styles represent a spatial and temporal distinction between the proximal environment of subvolcanic activity and the distal to transitional condition derived from volcanic environments. The Cu(-Au) or Fe-Mo-W deposits are proximal to a magmatic source, whereas the polymetallic or the precious-metal deposits are more distal to transitional. On the basis of the overall ${\delta}^{18}O_{H2O}$ values of various ore deposits in these areas, it can be briefed that the ore fluids show very extensive oxygen isotope exchange with country rocks, though the ${\delta}D_{H2O}$ values are relatively homogeneous and similarly restricted.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.655-665
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• 2014

The effect of modified atmosphere packaging (MAP) on kohlrabi (Brassica olerace L. gongulodes group)'s quality and antioxidant molecule during storage was examined to determine the optimal film package for maintaining freshness. To extend shelf life, MAP was tested using PE $50{\mu}m$ and oriented polypropylene (OPP) films with oxygen transmission rate (OTR) at 3,000, 10,000, $15,000mL/m^2/day/atm$. The OPP film packaging with modified oxygen transmission rate showed a delay in a weight loss and extended storage period. The package with OTR 3000 attained the desired gas composition of $O_2$ 3.2-6.7 kPa and $CO_2$ 13.1-19.8 kPa, in storage at room temperature. Kohlrabi stored in this package showed the lowest weight loss and the highest visual quality. Deterioration and off-odor were developed more rapidly in PE $50{\mu}m$ towards the end of the storage at room temperature. However, there are no differences among OTR films in visual quality and off-odor until 60 days at cold storage. Vitamin C content of kohlrabi was reduced rapidly in OTR 15000 with high transmission rate and showed less loss in PE $50{\mu}m$ and OTR 3000 in both room temperatures and cold storage. Results revealed that an OPP film with OTR 3000 extended the shelf life of kohlrabi in storage with maintained quality and vitamin C.