• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.263-272
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• 2005

Chlorine disinfection has been used in drinking water supply to disinfect the water-borne microbial disease which may cause to serious human disease. it is still the least costly, relatively easy to use, Chlorination is the primary means to disinfect portable water supplies and control bacterial growth in the distribution system. However, chlorine reacts with natural organic matter(NOM), that presents in nearly all water sources, and then produces disinfection by-products(DBPs), that have adverse health effects. Although the existent DBPs have been reported in drinking water supplies, it is not feasible to predict the levels of the various DBPs due to the complex chemistry reaction involved. 1. The objectives of this study is to investigate seasonal variation difference concentration of DBPs in the plant to tap water. The average concentration of THMs was 20.04 ${\mu}g/{\ell}$ , HAAs 8-15 ${\mu}g/{\ell}$ , HANs 2-4.5 ${\mu}g/{\ell}$ respectively. 2. Distant variation of DBPs furmation by the distance is that THMs concentration increased by 17% at 2km point from the plant and by 28% at 7km and HAAs, HANs also increase each by 16%, 32% at 2 km from the plant and 35%, 56% at 7 km. DBPs increase in water supply pipe continually, 3. The seasonal occurrence of BBPs is that in May and August DBPs concentration is very higher than in march, in May DBPs concentration is highest. The temperature is main factor of DBPs formation, precursor also. 4. Precursor which was accumulated for winter flowed into the raw water by flooding in spring and summer and produced DBPs. 5. Therefore for the supply of secure drinking water, it is required to protect precursor of flowing into raw water and to add to BCAA and DBAA to drinking water standards.

• Food Science and Preservation
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• v.23 no.2
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• pp.218-224
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• 2016

The quality and shelf life of noodles containing onion powder (0, 3, 5, and 10%) were investigated. The pH of raw noodles decreased by increasing the concentration of onion power. The weight, volume, and water absorption of the cooked noodles were comparable, irrespective of onion powder concentrations. Color L and a values of raw noodles decreased, while b value increased by addition of onion powder. However, no considerable differences in color values were observed among the control and onion noodle groups after cooking (p<0.05). The total polyphenol contents and DPPH radical scavenging activities of raw and cooked noodles increased with increasing onion powder concentrations, although the latter had lower values. In the aspect of texture, the control group showed higher hardness and chewness than those of noodle containing onion powder, except for springiness. The results of raw noodle storage at $10^{\circ}C$ for 12 days indicated that raw onion noodles, especially those with 5% onion powder added, could be preserved for at least 6 days longer than the control noodle. In the sensory evaluation of cooked noodles, no significant differences in appearance, taste, flavor, texture and overall acceptability were observed between the control and onion noodle groups. This study indicates that the addition of 5% onion powder could improve the functionality and shelf life of noodles.

• Food Science and Preservation
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• v.17 no.1
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• pp.139-144
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• 2010

This study was carried out to investigate potential applications of the extract of Castanopsis cuspidata var. sieboldii $N_{AKAI}$ nut as a functional food ingredient. The pH and $^{\circ}Brix$ of nut were 6.43 and 3.17, respectively. L, a and b values as Hunter's color were 83.07, 1.49 and 10.48, respectively. Total content of monosaccharide was 54.26 mg% and organic acids were composed of oxalic acid 495.37 mg%, formic acid 200.03 mg%, malic acid 93.65 mg%, citric acid 27.80 mg%, and succinic acid 16.61 mg%. Total phenolic contents in various solvent extracts were as follows: water 27.69 mg%, 75% ethanol 16.50 mg%, ethyl acetate 16.50 mg%, and methanol 10.30 mg%. The antioxidant activity ($SC_{50},\;{\mu}g/mL$) of the nut extracts by various solvents was in the order of ethyl acetate 74.88 > methanol 155.00 > n-hexane 213.33 > ethanol 249.33 > butanol 274.78 > chloroform 314.67 > 75% ethanol 848.33 > water extracts 869.67. The results indicated that the extract of C. cuspidata nut contained a potential food ingredient.

• Journal of Mushroom
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• v.16 no.3
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• pp.131-139
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• 2018

The king oyster mushroom (Pleurotus eryngii) is widely consumed because of its flavor, texture, and its functional properties such as antioxidant activity and prebiotic effects. However, long-term product storage and transportation (e.g., export) are difficult because of its limited durability. The shelf-life of king oyster mushroom is affected by environmental factors such as temperature, humidity, gas composition, and ventilation, which may affect sensory characteristics including respiration rate, texture, moisture, flavor, color, and pH. The major problems regarding storage of mushrooms are browning, flavor changes, and softening. To address these problems, novel preservation techniques were developed, and more durable variants were bred. Different drying methods, gamma irradiation, chitosan coating, modified atmosphere (MA) packaging, and controlled atmosphere (CA) storage were evaluated in order to extend the shelf-life of king oyster mushrooms. Freeze drying showed better results for the preservation of mushrooms than other drying methods. Irradiation with 1 kGy was more effective for extending mushroom shelf-life than higher doses. The preservative performance of chitosan-based films was improved by combining the compound with other hydrocolloids, such as oil, protocatechuic acid, and wax. The CA storage conditions recommended for king oyster mushrooms are 5kPa $O_2$ and 10 to 15kPa $CO_2$ at temperatures below $10^{\circ}C$. Active MA packaging with microperforated PP film was also effective for maintaining quality during storage.

• Food Science and Preservation
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• v.11 no.4
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• pp.441-447
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• 2004

To elucidate changes in qualifies of pork and beef during storage and identify decay point, beef (loin, tenderloin, plate) and pork (belly, loin, thigh) were stored at $4^{\circ}C$, and their pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), electronic nose analysis, and sensory evaluation were performed. Belly of pork had higher values in pH, VBN and TBARS, compared to loin and thigh of pork. Electronic nose analysis clearly indicated a difference in principal component score between day 0 and day 12 of storage. Sensory evaluation showed that pork began to away at day 4 of storage and not edible after 6 days. Loin and tenderloin of beef had higher values in pH and VBN, compared to plate of beef. Regarding TBARS, all beef samples had the similar values at the beginning of storage, but loin of beef had a drastic increase after 8 days of storage, differently from tenderloin and plate of beef. Plate of beef had lower values in overall. Electronic nose analysis of beef showed the similar results with those of pork.

• Food Science and Preservation
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• v.14 no.5
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• pp.445-450
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• 2007

This studies were engaged to investigate the potential us of Curcuma aromatica Salab. as a food ingredients. The antimicrobial activity of Curcuma aromatica Salab. extract (CE) and effect on shelf life of the cooked rice were examined. The antimicrobial activity of CE showed apparently against Bacillus cereus, B. subtilis and B. megaterium. The minimum inhibitory concentration (MIC) of CE was 0.15% for B. cereus md 0.2% for B. subtilis and B. megaterium. The antimicrobial activity of CE remained relatively high after heat treatments(30 min at 80 and $100^{\circ}C$, 15 min at $121^{\circ}C$). The shelf life of cooked rice containing above 0.05% CE increased more 1 or 2 days than that of control at $30^{\circ}C$, The texture of cooked rice was improved by addition of above 0.01% CE. The sensory quality of cooked rice with CE did not show significant difference between 0.00% and 0.05% in taste and overall acceptability but decreased above 0.10% in taste, color, flavor and overall acceptability.

• Journal of Ecology and Environment
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• v.43 no.4
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• pp.438-453
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• 2019

Background: To investigate the trends of succession occurring at the Pinus thunbergii forests on the lowlands of Jeju Island, we quantified the species compositions and the importance values by vegetation layers of Braun-Blanquet method on the Pinus thunbergii forests. We used multivariate analysis technique to know the correlations between the vegetation group types and the location environmental factors; we used the location environment factors such as altitudes above sea level, tidal winds (distance from the coast), annual average temperatures, and forest gaps to know the vegetation distribution patterns. Results: According to the results on the lowland of Jeju Island, the understory vegetation of the lowland Pinus thunbergii forests was dominated by tall evergreen broad-leaved trees such as Machilus thunbergii, Neolitsea sericea, and Cinnamomum japonicum showing a vegetation group structure of the mid-succession, and the distribution patterns of vegetation were determined by the altitudes above sea level, the tidal winds on the distance from the coast, the annual average temperatures, and the forest gaps. We could discriminate the secondary succession characteristics of the Pinus thunbergii forests on the lowland and highland of Jeju Island of South Korea. Conclusions: In the lowland of Jeju Island, the secondary succession will progress to the form of Pinus thunbergii (early successional species)→Machilus thunbergii, Litsea japonica (mid-successional species)→Machilus thunbergii (late-successional species) sequence in the temperate areas with strong tidal winds. In the highland of Jeju Island, the succession will progress to the form of Pinus thunbergii (early successional species)→Neolitsea sericea, Eurya japonica (mid-successional species)→Castanopsis sieboldii (late-successional species) sequence in the areas where tidal winds are weak and temperatures are relatively low. However, local differences between lowland and highland of Jeju Island will be caused by the micro-environmental factors resulting from the topographic differences and the supply of tree seeds. From the characteristics of succession study, we could properly predict and manage the Pinus thunbergii forest ecosystem on lowland and highland of Jeju Island.

• Food Science and Preservation
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• v.16 no.5
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• pp.636-643
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• 2009

Inactivation by UV-C irradiation of Escherichia coli O157:H7 and Listeria monocytogenes inoculated onto washed carrots was examined. Carrot samples were inoculated with 6-7 log CFU/mL of E. coli O157:H7 or L. monocytogenes, treated with doses of 0, 1, 3, 5, or $10\;kJ/m^2$ UV-C, and stored at $4{\pm}1^{\circ}C$ for 8 d. The populations of E. coli O157:H7 and L. monocytogenes significantly decreased with increasing irradiation dose (p<0.05). In particular, E. coli O157:H7 and L. monocytogenes populations fell significantly by 2.35 and 2.38 log CFU/g at $10\;kJ/m^2$, respectively, compared to control values. UV-C irradiation inhibited color changes and decreased the whiteness index in carrot during storage, compared to controls. Sensory evaluation results showed that UV-C-treated carrots had better sensory characteristics than did the control. Therefore, the results suggest that UV-C irradiation could be useful to improve the microbial safety and sensory qualities of fresh-cut carrots during storage.

• Food Science and Preservation
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• v.14 no.2
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• pp.160-164
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• 2007

This study was performed to investigate the effects of mixing methods, storage period, and dilution ratio of Dangyuja-sugar mixture on the customer preferences for Dangyuja-tea. Most sensory characteristics such as bitterness, flavor, and taste are influenced more by mixing methods of Dangyuja-sugar mixtiue than by storage period. The Dangyuja-sugar mixture prepared by slice cutting is preferred to those prepared by operating electric mixer, The preference test showed that the appearance is not influenced by storage period but by mixing methods, whereas the tne and texture is more affected by storage period in which the 24 month storage is preferred to 12 month storage. therefore, the overall preference fer Dangyuja-tea is the on that prepared with 20% contents of Dangyuja-sugar mixture which is slice-cut and 24 month stored.

• Food Science and Preservation
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• v.19 no.4
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• pp.604-610
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• 2012

The nutritional composition and in vitro anti-oxidant activities of blueberry (Vaccinium ashei) leaf extract were investigated to examine their physiological characteristics. Calcium was the most abundant mineral. The principal free sugars were glucose, sucrose, maltose, and fructose. The amino acids were mainly composed of glutamic acid and aspartic acid. The fatty acids consisted mainly of 40.94% saturated fatty acid and 54.35% unsaturated fatty acid. In addition, the 112.64 mg% of vitamin C was analyzed as a natural anti-oxidant. Based on the bioactivity-guided isolation principle, the resulting ethanolic extracts from the blueberry leaf were divided into several fractions of n-hexane, chloroform, ethyl acetate, and water. The ethyl acetate fraction showed the greatest total phenolic content. The total phenolics and flavonoid were 50.51 mg of GAE /g and 13.09 mg%, respectively. The ABTS-radical-scavenging activity of the ethyl acetate fraction was 97.53% at a concentration of 500 ${\mu}g/mL$. The ferric-reducing anti-oxidant power of the ethyl acetate fraction increased in a dose-dependent manner. The results suggest that the ethyl acetate fraction of the blueberry leaf extract has good in vitro anti-oxidant activities and excellent nourishment, and can thus be useful food resources.