• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.318-331
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• 1995

The c - axis oriented single crystal of $LiNbO_3$ and $LiNbO_3$ : 5mol%MgO was success-fully grown by Floating zone method using halogen lamp as a heat source. The effects of the sintering condition of the feed rod and the atmosphere gas during the crystal growth on the be havior of the feed rod/melt interface were studied for growing crystal with the high quality, and then, the optimum growth conditions were determined by studying the experimental param eters, such as gas flow rate, pulling rate, rotation speeds of the feed rod and the seed. The grown crystals were analyzed using the chemical etching to observe the tch pattern and the ICP (Inductively Coupled Plasma) to determine the composition uniformity and the impurity content of Fe. The effects of additive (5 mol % MgO) on the transmittance and refractive index was, also, analyzed. In order to compare the nonlinear optical oharacteristics of $LiNbO_3$ with those of the other optical materials, the nonlinear optical refractive index ($n_2$) was calcu l lated using the measured refractive index.

• Applied Biological Chemistry
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• v.18 no.1
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• pp.16-22
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• 1975

This experiment was carried out to investigate the physiological characteristics of two original yeasts, 5-Y-5 and 6-Y-6, which selected from 24 Takju yeasts and three mutants, 30-24,30-81 and 40-27. induced from two original yeasts by the irradiation of UV light. The results were summarized as follows. 1) Alcohol tolerances of three mutants were decreased in some degree as compared with those of original yeasts. 2) Tolerances of lactic and citric acids of acid producing mutant 30-81, was increased than those of original yeasts. 3) In the case of using ammonium sulfate as a nitrogen source, two original yeasts and three mutants required Ca-pantothenate as a essential growth factor and four strains of yeasts except the mutant, 30-81, required biotin as a stimulated growth factor, When asparagine was used as a nitrogen source, two original yeasts and three mutants showed the same as above result but the stimulated effect of biotin was far less. 4) Propagation powers of the mutants were weaken than those of original yeasts, particular that of acid producing mutant, 30-81, was the weakest in the three mutants. 5) The optimum temperature for fermentation of original yeasts were $30^{\circ}C\;to\;35^{\circ}C$ but three mutants were $25^{\circ}C\;to\;30^{\circ}C$. 6) The optimum pH for fermentation of original yeasts were pH 5 to 6, and there is no appreciable difference between original yeasts and three mutants. The fermentation power of mutant,30-81, was decreased more rapidly than those of other mutants according to approach neutral. Three mutants were more sensible to heat than original yeasts. 7) Two original yeasts and three mutants were inhibited more over 20 percent of sugar for fermentation and three mutants were more sensible to sugar concentration than original yeasts.

• Journal of Animal Science and Technology
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• v.49 no.5
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• pp.657-666
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• 2007

This study was conducted to evaluate the effects of dietary addition of caprylic acid(CA)-cyclodextrin (CD) complex on in vitro fermentation characteristics, total gas and methane production. Experiment was done with six treatment groups; 1) no CA-CD complex(control), 2) CA 20 mg(T1), 3) CD 830 mg(T2), 4) CA-CD complex 425 mg(T3), CA-CD complex 850mg(T4), CA-CD complex 1,700 mg(T5). Ruminal pH, ammonia and total VFA concentrations of T2, T3, T4 and T5 were lower(P<0.05) than those of control and T1 for the 12h incubation. The increase in molar percentage of propionate was observed in T4 and T5 compared with control and T2 for the 8h incubation(P<0.05), however, the ratio of acetate to propionate was unchanged in all treatments. Total gas of T1 was lower than that of control, but T2, T3, T4 and T5 were higher compared with control for 12h incubation(P<0.05). If the methane ratio (as %) to total gas for all treatments was compared, T3, T4 and T5(CA-CD supplemented groups) averaged 2.7% whereas control, T1 and T2 showed 3.4, 2.8 and 5.1%, respectively. Therefore, according to these results, it might be concluded that supplementation of CA-CD complex could reduce methane production without disrupting ruminal fermentation.

• KSBB Journal
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• v.9 no.1
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• pp.26-34
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• 1994

When effects of exogenous hormone on hairy root cultures of Raphanus sativs cv. Chungpihongsim examined, the highest anthocyanin synthesis and disorganization were observed when 2, 4-D was supplemented to the culture medium Cytokinins showed early weak induction after transfer and ABA showed inhibitory effect and GA3 showed no effects in anthocyanin synthesis. Hormones except for 2, 4-D in 1 mg/$\ell$ concentration did not induce disorganization of hairy root and retarded growth of hairy root. Time-course changes in anthocyanin synthesis, phenylalanine ammonia-lyase activity and chalcone synthase activity were examined in culture condition contalning 2, 4-D and kinetin. In a medium containing 2, 4-D, anthocyanin synthesis began to increase on the 9th day and reaching maxima on the 18th day after transfer. Maximum peak of PAL activity appeared on the 3-9th day and another minor peak appeared on the 18th day. CHS activity increased from 9th day, reaching maximum on the 18th day and remained at a relatively high level for culture period. In a medium containing kinetin, anthocyanin synthesis increased temporarily on the 6-9th days, early days after transfer and maintained at a low level for remaining culture period. Peak of PAL activity appeared on the 6th day and CHS activity increased from the 6th days, reaching maxima about 18th day and remained at a relatively high level. In particular, addition of kinetin after preculture in hormone free medium for 2 weeks which was thought of wound healing period showed no effects in anthocyanin synthesis. This results showed that stimulation of anthocyanin synthesis by 2, 4-D and kinetin was meaningfully connected with changes of PAL, CHS activity, and then suggested rate-limiting role of CHS on anthocyanin synthesis in that there is close correlation between anthocyanin synthesis and changes of CHS activity in time-course. Besides, it is considered that cytoklnins involving kinetin stimulated anthocyanin synthesis be due to "wound response" by cutting of young roots, and that difference in time-course peak and PAL, CHS activities expressed by 2, 4-D and kinetin result from occurrence of isozyme which have different regulatory mechanism.mechanism.

• Korean Journal of Agricultural Science
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• v.19 no.1
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• pp.1-8
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• 1992

This experiment was conducted to improve the germination when we sowed Chinese milk vetch (Astragalus sinicus L. Local vas. Jinjoo) in the up-land.. The results are summerized as follows 1. There is no difference on the germination of Chinese milk vetch from $15^{\circ}C$ to $35^{\circ}C$. Germination ratio is 7l%, speed is 60% and mean of germinating day. is about 4. But at $10^{\circ}C$ germination ratio and speed are decreased as 65%, 8% but mean of germinating day is increased as 8. 2. Chemicals used for improve of germination $KNO_3$, $H_2SO_4$, HCl, NaOCl, NaOH and GA were increased about 6~8% of germination ratio. 3. Germination in response to soil covering up depth, surface sowing showed 68% of germination and not more than 4cm the seed is germinated 60% but not less than 6cm, germination ratio is not more than 50%. 4. Soil water content needed in the germination is proper about 70~80% of field water capacity and the ratio is 65% but not. more than 40% germination ratio is not more than 31%. 5. Germination in response to seed treatment (1 day sbsorption /1 day dry) germination ratio is not decreased when it treated 2 times but not less than 3 times it decreased seriously and not less that: 5 times it decreased not more than 31%. 6. Germination in response to seed largement, small seed is not good for germination, so seeds harvested after the majority of the seed is ripened.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.277-285
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• 2010

The objective of this study was to manufacture spent layer chicken meat products by natural freeze-drying. The spent layers of chickens that were slaughtered at 80 wk were obtained from a local slaughter house and separated into two halves of carcasses. The samples were divided into the following groups: 1) control (non-curing), 2) curing, and 3) curing with 2% trehalose before drying. The cured meats were placed at $2^{\circ}C$ for 7 d and then transferred to a natural drying spot located in Injae City, Gangwondo, Korea. The experiment was conducted from January to March in 2008. The average temperature, RH, and wind speed were $-1.5^{\circ}C$, 63%, and 1.8 m/sec, respectively. The cured treatments showed higher pH, lower Aw and lower shear force value compared with the control. Based on the results of TBARS (2-thiobarbituric acid reactive substances) level and volatile basic nitrogen value, lipid oxidation and protein deterioration were inhibited in curing treatments during drying. Trehalose acted as a humectant because it maintained a lower water activity despite the relatively higher moisture content during drying. The polyunsaturated fatty acids content and sensory attributes were higher in cured treatments than in the control during drying. Most of the bacterial counts in the treated groups were lower by 2 Log CFU/g after 1 mon of drying, and Salmonella spp. and Listeria spp. were not found in any treatment. There was also no microbial safety problem associated with dried meat products. Based on the results of this experiment, dried meat products could be manufactured from precured spent layer chickens by natural freeze-drying during winter.

• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.299-305
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• 2015

The Folin-Denis assay using the Folin-Ciocalteu (F-C) reagent has been commonly used for analyzing the total phenolic compound content in various food products. In the present study, the effects of proteins on the reactivity of the F-C reagent with different phenolic compounds were investigated. Bovine serum albumin (BSA) or skim milk proteins showed a concentration-dependent increase in color response in the Folin-Denis assay; these proteins decreased the color response of most phenolic compounds tested. The reactivity of phenolic compounds was significantly less pronounced in the presence of BSA and this interference was greater at higher concentrations of phenolic compounds. The reactivity of phenolic compounds with the F-C reagent was reduced significantly by their oxidation; the reaction of the oxidized products with the F-C reagent was more severely affected by BSA. The interfering effects in the Folin-Denis assay might be attributable to binding interactions of phenolic compounds with proteins.

• Journal of Conservation Science
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• v.36 no.6
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• pp.533-540
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• 2020

Mt. Neoseongsan (NSS) is the only natural Neorok source in Korea. The geological, historical, and cultural values of NSS were recognized in 2013, and NSS has since been designated and maintained as a natural monument (No. 547), which has restricted the research and utilization of NSS Neorok. The limited NSS Neorok supply has hindered the restoration research of traditional pigments. Recently, a large amount of Neorok has been mined from Mt. Gwangeongsan (GJS) and is expected to be the main supply source of Neorok for restoring traditional pigments. Therefore, this study analyzed the characteristics of NSS- and GJS-Neorok-based pigments to evaluate the feasibility of substituting GJS Neorok for NSS Neorok in pigments. The NSS Neorok was mostly comprised of celadonite, whereas the GJS Neorok included minerals containing glassy phases such as celadonite, cristobalite, tridymite, etc. Because both Neorok samples were vitrified under identical conditions, the GJS Neorok grains were larger than the NSS Neorok ones. The GJS Neorok pigment showed that the chromaticity, grain size, oil absorption, and stability varied depending on the mineral types and contents. In particular, GJS-2 and NSS Neorok showed similar mineral compositions, physical properties, and stabilities, suggesting that GJS-2 can be substituted for NSS Neorok, which has been difficult to source and utilize ever since NSS was designated as a natural monument.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.8
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• pp.1144-1150
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• 2012

The study of quality and salting characteristics of root vegetables other than Chinese cabbage was done to develop different kinds of Kimchi. The root vegetables lotus (Nelumbo nucifera) and lance Asia bell (Codonopsis lanceolata) were evaluated as main ingredients for Kimchi by measuring their physico-chemical and microbial properties. Salinity, pH, titratable acidity, reducing sugar, firmness, color change, moisture content, total viable counts, and lactic acid bacteria were investigated to identify adaptability for Kimchi. The initial pH of lotus and lance Asia bell showed 5.7 to 6.3 during the salting period, and the pH decreased with increasing salting periods. The reducing sugar contents of lance Asia bell showed 34.1 to 35.6 mg/g, which were significantly higher compared to lotus 3.2 to 3.4 mg/g. Titratable acidity also showed higher in salted lance Asia bell at 0.36 to 0.4%, while lotus showed 0.17 to 0.27%. Lactic acid producing bacteria increased in lance Asia bell during salting periods and reached $2.1{\times}10^4CFU/g$ after 48 hr of salting. However, no lactic acid bacteria were detected in lotus. As a result of this physico-chemical and microbial analysis, lance Asia bell was more suitable as an ingredient of Kimchi than lotus.

• Food Science and Preservation
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• v.30 no.6
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• pp.1043-1055
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• 2023

This study was conducted to suggest an extraction method for preparing the extract from green tea leaves that possess enhanced antioxidant and antibacterial activities. Different ethanol concentrations were tested to recover phenolics and flavonoids, and 50% ethanol was the best under heat treatment (121℃, 15 min). The ethanol extract exhibited excellent DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and growth inhibition against B. cereus, B. licheniformis, S. aureus subsp. aureus, and A. hydrophila subsp. hydrophila. To enhance the antioxidant and antibacterial activities, cell-wall degrading enzymes (2.5% cellulose+2.5% pectinase, v/w dry sample) treatment and Saccharomyces cerevisiae fermentation were applied singly or in combination. The enzymatic treatment of green tea leaves notably increased extraction yield. However, the antioxidant and antibacterial activities of the extract were lower than those of the control (heat-treated 50% ethanol extract). In contrast, the yeast fermentation alone did not affect the yield, but enhanced antioxidant and antibacterial activities, contributing to the increase in the extract's total phenolic and flavonoid contents.