• Korean Journal of Poultry Science
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• v.17 no.3
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• pp.203-209
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• 1990

This study was carried out to investigate the effects of packaging methods on the shelf-life of refrigerated chicken parts at $4^{\circ}C$. The microbial and physicochemical changes of chicken parts during storage periods were also examined to determine the shelf-life. The shelf-life of chicken parts dipped in 7.5% potassium sorbate with different packaging methods such as conventional packaging, vacuum packaging and modified atmosphere packaging was determined. The shelf-life of conventional packaged chicken parts dipped in 7.5% potassium was $19\pm3$ days and the shelf-life of vacuum packaged chicken parts dipped in 7.5% potassium sorbate was $30\pm5$ days. The shelf-life of 10% $CO_2$ and 90% $N_2$ gas contained packaged chicken parts dipped in 7.5% potassium sorbate was $26\pm4$ days while 20% $CO_2$ and 80% $N_2$ gas contained packaged chicken parts dipped in 7.5% potassium sorbate was $30\pm5$ days.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.134-144
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• 2001

This study was conducted to investigate physicochemical and microbiological properties during composting process when pig manure was composted with some bulking agents(Saw dust, Rice hull, Crushed wood). The pig manure consisted of 2.95% total nitrogen, 4.55% $P_2O_5$, 2.07% $K_2O$, 81.2% organic matter and 14.0 C/N, dry base. The inorganic content of bulking agents were similar one another, and C/N ratio was Saw dust 392. Rice hull 91.5, Crushed wood 266. The temperature of Saw dust composting slowly increased at initial stage, whereas one of Rice hull and Crushed wood rapidly increased and stabilized similarly to outdoor temperature after about 2 month. The pH of compost increased during initial 1 month after decreasing, but thereafter decreased rapidly. The C/N ratio rapidly decreased at initial stage, and it slowly decreased after 1 month. Total nitrogen somewhat increased according to composting process. Ammonium-nitrogen increased until 60th day, and thereafter it was rapidly inclined to decrease. The population of aerobic bacteria, Bacillus spp., actinomycetes and fungi increased up to > $10^{10}cfu\;g^{-1}$ fresh weight, > $10^7$, > $10^8$ and > $10^6$, respectively in Rice hull and Crushed wood composting, and more than ones in Saw dust composting, and specially actinomycetes. The persuasive Bacillus spp. isolated from composting process were B. lentimorbus, B. licheniformis, B. pumilus, B. megaterium, etc.

• Applied Chemistry for Engineering
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• v.19 no.3
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• pp.326-331
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• 2008

The purpose of this work is to develope sodium-containing nonstoichiometric apatitic coatings on solid substrate. The apatitic coatings prepared at different concentrations of sodium salt indicated that the presence of sodium ions exerted significant effects on the physicochemical properties of the apatitic coating including surface morphology, chemical state, and Ca/P ratio. The variation of these properties was sustained up to 0.01 mM of sodium ion concentration. The ratio of calcium to phosphorus was varied from 2.18 to 2.03 which indicated the apatitic coating prepared in this study was calcium-rich nonstoichiometric apatite. The structure of all the samples appeared to be low crystalline. In the presence of sodium ion within the apaptitic coating, the adhesion of human osteoblast-like SaOS-2 cells was significantly promoted. On the other hand, the proliferation of the cells on the apatitic coatings was decreased with the increase of sodium ions. This reverse response of SaOS-2 cells indicates that the interaction between SaOS-2 and apatitic surface triggered considerable changes in intracellular mechanisms including cellular signal transductions.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.212-220
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• 2009

In this study, we analyzed fish compositions and ecological characteristics such as trophic guilds and tolerance guilds in association with water quality characteristics in Masan Reservoir during November 2008. Total number of species were 12 species (6 families) and the dominant species were Zacco platypus, Hemiculter eigenmanni, and Pseudorasbora parva. We found three Korean endemic species and one exotic species, Carassius cuvieri. According to the analysis of ecological indicator characteristics, relative proportion of tolerant and omnivore species was 98% of the total indicating that probably, the fauna was influenced by physical habitat disturbance and physicochemical degradations. Fish distribution analysis along with littoral zone showed that the most fishes (${\sim}$95%) were observed in the littoral zone where emerged macrophytes were well developed. Also, substrate analysis indicated that the most species were found near silt area (11 species, 91.7%), so that the significant differences were found between the substrate types. Analysis of water quality indicated that concentrations of total phosphorus (TP) and chlorophyll-a (ChI-a) as a lake trophic indicator were judged as eutrophic states, respectively and COD as an indicator of organic matter pollution averaged 10.9 mg $L^{-1}$. Based on the water quality, this system were influenced by the nutrient enrichments and organic matter. The degradations of water quality in Masan Reservoir resulted in trophic compositions of fish (increase of omnivore species) and the dominance of tolerant fish. This Monitoring data may contribute changes of fish fauna and compositions in relation to habitat modifications and chemical water quality degradations in the future.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.556-565
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• 2014

In this study, we evaluated changes in physicochemical properties, total phenol and isoflavone contents, and antioxidant activity during soymilk fermentation by a potential probiotic Lactobacillus plantarum P1201. The P1201 strain showed survival rates of 58.14% and 62.22% after 4 h exposure to acid and artificial gastric acid conditions (pH 2.5), respectively. The optimal conditions for soy-yogurt fermentation by L. plantarum were determined to be as follows: temperature of $35^{\circ}C$, seed volume of 5.0%, and sucrose content of 10.0%. The total phenol and isoflavone contents and antioxidant activity were higher in soy-powder milk (SPM) yogurt than soymilk yogurt. In particular, the highest levels of isoflavone-aglycones, such as daidzein, glycitein, and genistein (91.50, 12.34, and $61.39{\mu}g/g$, respectively), were observed after 48 h of SPM fermentation. Thus, these results suggest that the soy-yogurt extract could be used as a potential source of natural antioxidants in food.

• Korean journal of food and cookery science
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• v.4 no.2
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• pp.21-30
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• 1988

To study the optimum fermentation and aging conditions for preparation of Andong Sikhe which is consumed in the northern Kyungbuk province as a traditional beverage, Sikhe were fermented and aged at $12^{\circ}C$ for 48, 60 and 72hrs and fermented at 40, 50. and $60^{\circ}C$ for 2, 3, and 4hrs and then aged at $12^{\circ}C$ for 20 hrs, Non-volatile organic acids and free sugars were analyzed by GC and HPLC, respectively, and sensory test was performed. Sikhe fermented at $40^{\circ}C$ for 3hrs and aged at $12^{\circ}C$ for 20hrs was evaluated the most favorable one by sensory test. This Sikhe had the lowest pH 4.6~4.7 among sample and 14.6% of sugar. The sugar content was lower than those of Sikhe Fermented at $50^{\circ}C$ and $60^{\circ}C$. In organic acid analysis, the concentration of malate 67.53%/mg in this Sikhe was the highest. Lactate, succinate and maleate were produced more in this Sikhe than in any other ones. Oxalate which was existed before fermentation was not found in the Sikhe, and a small amounts of citrate and fumarate were produced. In sugar analysis, maltose was dominant 11.56%, glucose 1.25% and fructose 0.45%.

• Korean journal of food and cookery science
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• v.20 no.1
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• pp.11-16
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• 2004

This study was conducted to increase the value of Aster glehni as a useful food resource. The Hunter L, a and b Values of Aster glehni leaves Were 34.23${\pm}$2.80, -10.59${\pm}$1.80 and 13.29${\pm}$2.51, respectively. The Shearing force and contents of tannin and dietary fiber were 4701.2g, 100.9ppm and 37.1％, respectively. The minerals identified in Aster glehni were Ca (6.93mg/kg), K (45.36mg/kg), Mg (1.70mg/kg), Fe (0.36mg/kg) and Na (1.26mg/kg). Aster glehni Kimchi was packed in polyethylene film (200g) and fermented at 20 and 4$^{\circ}C$. With regards to the color changes, the Aster glehni Kimchi fermented at 20$^{\circ}C$ showed greater increases in the Hunter L, a and b values than a 4$^{\circ}C$. The pH of the Kimchi decreased and acidity increased with storage time at both temperatures. The ascorbic acid contents decreased sharply with storage time and by about 85％ at 20$^{\circ}C$ after 5 days, and 73％ at 4$^{\circ}C$ after 30 days. The reducing sugar content also decreased with storage time at both 20 and 4$^{\circ}C$. The results of the sensory evaluation showed the optimum ripening times of the Aster glehni Kimchi to be 1∼3 days at 20$^{\circ}C$ and less than 20 days at 4$^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.8-14
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• 1996

The effects of temperature variations during storage, pasteurization on the quality of orange juices were investigated. To evaluate the quality of orange juices pasteurized at 75, 85 and $95^{\circ}C$ for 15 sec, microbial and physicochemical measurements and sensory evaluations were conducted during storage at 10, 20 and $30^{\circ}C$ for 32days. Color(lightness) and contents of vitamin C and sucrose were not changed at $10^{\circ}C$, but decreased at $20^{\circ}C$ and $30^{\circ}C$ as the storage time was increased. The pasteurization temperature had a little effect on the color and the contents of vitamin C and sucrose. Furfural contents were apparently increased as the storage period extended, but the samples stored at $10^{\circ}C$ had less amounts than the others. On the other hand, the pasteurization temperature did not affect furfural accumulation. Furfural was produced as a result of the degradation of vitamin C and deterioration of the color. The PH values were not changed during the entire storage period, and microorganisms were not detected in most of the samples. The result of sensory evaluation indicated no taste difference between the control and the sample stored at $10^{\circ}C$, but the taste changes were recognized when the samples were stored over 24 and 20 days at $20^{\circ}C$ and $30^{\circ}C$, respectively. Therefore, the storage temperature affected the quality of orange juices more markedly than the pasteurization temperature, and the storage at lower temperature appears to reduce the deterioration of orange juices.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.463-470
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• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.104-110
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• 2015

In order to develop new Kalopanax pictus shoot Jangajji (KJ) with low salt concentration, physicochemical changes of KJ soaked at different concentration of soybean sauce (10~50%) were investigated for 50 days. The pH of KJ increased significantly with increasing concentration of soybean sauce in soaking solution (P<0.05). Titratable acidity and NaCl concentration of all KJ increased during storage for 50 days at $10^{\circ}C$. The total bacterial count slowly increased during early storage time and reached its highest level (4.74 log CFU/g) after storage for 30 days. KJ-20 (KJ added with 20% soy sauce) showed the highest scores for taste, flavor, texture, and overall acceptability. The total polyphenol and flavonoid contents of KJ extract increased with increasing concentration of soybean sauce. DPPH and ABTS radical scavenging activities of KJ extract were 27.22% and 38.37% (control), 40.74% and 43.65% (KJ-10), 41.79% and 50.37% (KJ-20), 43.09% and 52.60% (KJ-30), 48.62% and 53.45% (KJ-40), and 50.85% and 60.79% (KJ-50), respectively.