다양한 냉동 및 해동공정 조합이 표고버섯의 품질에 미치는 영향

심준보 ( Jun Bo Shim ),조연지 ( Yeon Ji Jo ),최미정 ( Mi Jung Choi ),민상기 ( Sang Gi Min ),유선미 ( Seon Mi Yoo ),천지연 ( Ji Yeon Chun ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.3

본 연구는 다양한 냉동방법(강제송풍식냉동, 극저온냉동, 일반냉동)과 해동방법(자연해동, 유수해동, 초음파해동, 전자레인지해동)을 조합하여 처리했을 때 표고버섯의 물리적 품질에 미치는 영향을 관찰하고, 표고버섯의 품질을 유지하는 가장 효과적인 냉·해동 공정을 탐색하는 것이 목적이었다. 급속냉동법(강제송풍식냉동, 극저온냉동)으로 처리한 경우 표고버섯의 해동감량, 보수력, 수분함량은 큰 변화 없이 품질을 유지 하는데 효과적인 것으로 관찰되었다. 특히 보수력은 저속냉동(일반냉동) 및 저속해동(자연해동) 처리의 유무가 영향을 미치는 것으로 나타났다. 전단력의 경우 냉동방법에 의한 영향보다, 전처리 및 해동방법에 더 영향을 받는 것을 판단된다. pH 및 색도는 냉동방법 및 해동방법에 따라 거의 차이가 없는 것으로 관찰되었다. 표고버섯의 물리적 특성을 효과적으로 유지 할 수 있는 처리 조합은 급속냉동(극저온냉동) 및 급속해동(유수해동, 초음파해동, 전자레인지해동)을 한 경우이며, 또한 유지하고 하는 물리적 특성에 따라 냉동 및 해동방법을 다양하게 조합하여 처리한다면, 식품의 품질을 보존하는데 더욱 효과적일 것으로 사료된다. In this study, the potential of various freezing and thawing combinations was investigated for frozen storage of mushroom (Lentinula edodes). Lentinula edodes were sliced (5×5×50 mm) and then blanched in boiling water for 1 min. Samples were frozen by either natural air convection freezing (NCF, -24℃), air-blast freezing (ABF, -45℃), or liquid nitrogen freezing (LNF, -100℃). Frozen Lentinula edodes were thawed to a central temperature of 4℃ using either flowing water thawing (FT, 10℃), microwave thawing (MT, 400 W), sonication thawing (ST, 40 kHz, 10℃), or natural air convection thawing (NT, 20±5℃). In LNF Lentinula edodes, MT showed the most rapid thawing within 2.5 min followed by ST (30 min), FT (37 min), and NT (75 min). Quality attributes were evaluated by thawing loss, texture (hardness), water content, water holding capacity, pH, and color. A combination of LNF and MT induced the lowest thawing loss among tested combinations of each freezing and thawing. Thawing loss of frozen Lentinula edodes by LNF method was the lowest by MT. pH values NT of ABF method were significantly higher than blanched Lentinula edodes. In our study, MT minimized the quality changes of frozen Lentinula edodes when it was combined with ABF or LNF.

Effects of adsorbent sampling variables on the accurate measurement of isoprene

Choi In-Young,딘브엉,Kim Ki-Joon,Kim Dong-Eun,Jun Bong-Hyun,Lee Seungae,Park Young-Min,Kim Jo-Chun 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

Isoprene is an important volatile organic compound causing photochemical smog in the atmosphere; thus, accurate analysis of isoprene is essential. In this study, the effect of sampling conditions, including adsorbent types, sampling temperatures, and flow rates on the recovery of isoprene, was investigated. Common adsorption traps of isoprene, including Tenax TA/Carbosieve SIII, Tenax TA/Carbotrap, were used as adsorbents. Sampling temperatures varied from 25 °C to 40 °C. Sampling flow rates were 50, 100, and 200 mL min−1. It was found that the Tenax/Carbotrap trap revealed the highest isoprene recovery rate; however, the Tenax/Carbosieve SIII trap depicted more significant loss of isoprene than the other one. As for sampling variables, the lower the temperatures and flow rates concerned were, the higher the isoprene recovery was. It was concluded that sampling temperatures and flow rates should be ≤35 °C and ≤50 mL min−1 during a sampling process, respectively. In addition, Carbosieve SIII should not be used for isoprene sampling due to its poor recovery rate.

단기간의 금연과 일회성 유산소 운동이 흡연자의 심혈관 반응에 미치는 영향

송준경(Jun Kyung·choi),최현민(Hyun Min Choi),김종경(Jong Kyung Kim),노호성(Ho Sung Nho) 한국사회체육학회 2012 한국사회체육학회지 Vol.0 No.48

The purpose of this study was to investigate cardiovascular responses to a bout of aerobic exercise and acute smoking cessation in smoker. nine collegiate male smoker who have been smoking(duration of smoking: 7.5 ± 0.9yrs; number of cigarettes per day: 15.5 ± 1.5) participated in this study. All subjects performed PEI to stimulate Group IV metaboreceptor at immediately after smoking, 24hours after smoking cessation and smoking after a bout of aerobic exercise. they were measured SBP, DBP, HR, SV, CO, TVC using by finometer(FMS co, Netherland). As a result, compared to immediately after smoking, SBP, DBP, and MAP were significantly decreased 24-hours after smoking cessation at rest and PEI(p<0.05). In addition, smoking after a bout of aerobic exercise caused by post-exercise hypotension indicated that SBP was significantly decreased compared to immediately after smoking(p<0.05). also, the changes in DBP and MAP at rest and handgrip exercise were significantly smaller compared to immediately after smoking(p<0.05). Thus, the results showed that smoking cessation during 24-hours and a bout of aerobic exercise relieve excess blood pressure response and enhanced arterial baroreflex in collegiate male smoker. It is concluded that caused exercise pressor reflex by stimulated Group IV may be effective to improve excess blood pressure responses.

Doping effect of CNT and nano-carbon in magnesium diboride bulk.

Lim, Jun Hyung,Lee, Chang Min,Park, Jin Hyun,Choi, Jun Hyuk,Shim, Jong Hyun,Joo, Jinho,Lee, Young Hee,Kang, Won Nam,Kim, Chan-Joong American Scientific Publishers 2009 Journal of nanoscience and nanotechnology Vol.9 No.12

<P>We fabricated carbon nanotube (CNT)- and nano-carbon (NC)-doped MgB2 using an in-situ process in order to improve the critical current density (J(c)) at high magnetic field. We then evaluated the effects of the doped carbon content on phase formation, microstructure, and critical properties. CNT had a diameter and length of 5-10 nm and 0.5-1 microm, respectively, and NC was a sphere with a diameter of 5-30 nm. The bulk MgB(2-x)C(x) samples with x = 0, 0.05, and 0.1 for NC and CNT were fabricated by pressing into pellets and then sintered at 900 degrees C for 30 min. NC was more effective than CNT for carbon doping at the B site in MgB2 and, therefore, the NC-doped MgB2 samples had a lower critical temperature (T(c)) of 35.0-34.7 K than that of the CNT-doped samples (36.4-36.1 K). In addition, the J(c)(B) behavior was improved when NC and CNT were doped due to doping effect. Microstructural observation suggested that the nano-sized and unreacted NC particles and the nanodomain MgB2 acted as effective flux pinning centers for the NC- and CNT-doped MgB2, respectively.</P>

Studies on Lytic, Tailed Bacillus cereus-specific Phage for Use in a Ferromagnetoelastic Biosensor as a Novel Recognition Element

( In Young Choi ),( Joo Hyeon Park ),( Kyoung Min Gwak ),( Kwang-pyo Kim ),( Jun-hyun Oh ),( Mi-kyung Park ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.1

This study investigated the feasibility of the lytic, tailed Bacillus cereus-specific phage for use in a ferromagnetoelastic (FME) biosensor as a novel recognition element. The phage was immobilized at various concentrations through either direct adsorption or a combination of 11-mercapto-1-undecanoic acid (11-MUA) and [N-(3-dimethylaminopropyl)-N’-carbodiimide hydrochloride and N-hydroxysuccinimide (EDC/NHS)]. The effects of time and temperature on its lytic properties were investigated through the exposure of B. cereus (4 and 8 logCFU/ml) to the phage (8 logPFU/ml) for various incubation periods at 22°C and at various temperatures for 30 and 60 min. As the phage concentration increased, both immobilization methods also significantly increased the phage density (p < 0.05). SEM images confirmed that the phage density on the FME platform corresponded to the increased phage concentration. As the combination of 11-MUA and EDC/NHS enhanced the phage density and orientation by up to 4.3-fold, it was selected for use. When various incubation was conducted, no significant differences were observed in the survival rate of B. cereus within 30 min, which was in contrast to the significant decreases observed at 45 and 60 min (p < 0.05). In addition, temperature exerted no significant effects on the survival rate across the entire temperature range. This study demonstrated the feasibility of the lytic, tailed B. cereus-specific phage as a novel recognition element for use in an FME biosensor. Thus, the phage could be placed on the surface of foods for at least 30 min without any significant loss of B. cereus, as a result of the inherent lytic activity of the B. cereus-specific phage as a novel recognition element.

인체혈장 중 에탐부톨의 HPLC 분석법의 검증 및 단일용량 투여에 의한 약물동태 연구

곽혜선,박경호,최준식,송진아,성민경,장정옥,이화정 한국약제학회 2005 Journal of Pharmaceutical Investigation Vol.35 No.2

An HPLC method was employed for the determination of ethambutol in human plasma. After addition of internal standard (IS, octylamine, 2 μg/mL) and alkalinization of the plasma with 5 M sodium hydroxide, the drug and IS were extracted into the mixture of chloroform and diethyl ether (40:60, v/v). Following a 15-min vortex-mixing and a 10-min centrifugation, the organic phase was spiked with 100 pL of phenylethylisocyanate (2000 μg/mL) for chemical derivatization, mixed for 5 min and evaporated to dryness under a stream of nitrogen. The residue was reconstituted with 100 μL of mobile phase and 20 pL was injected into Cl8 column with a mobile phase consisting of methanol:water (70:30, v/v). The samples were detected utilizing an ultraviolet detector at 200 nm. The method was specific and validated with a limit of 0.15 μg/mL. Infra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification. The applicability of this method was demonstrated by analysis of human plasma after oral administration of a single 1200-mg dose to 20 healthy subjects. From the plasma ethambutol concentration vs. time curves, the mean AUC was 9.61 ± 1.64 μg hr/mL. and Cmax of 2.68 μg/mL reached 2.73 hr after administration. The mean biological half-life of ethambutol was 3.46 ± 1.21 hr. Based on the results, this simple and validated assay could readily be used in any pharmacokinetic studies using humans.

습식텍스쳐를 이용한 단결정 실리콘 광학적 · 전기적 특성 연구

한규민(Han Kyu-min),유진수(Yoo Jin-su),유권종(Yoo Kwon-jong),이희덕(Lee Hi-deok),최성진(Choi Sung-jin),권준영(Kwon Jun-young),이준신(Yi Jun-sin) 한국태양에너지학회 2010 한국태양에너지학회 학술대회논문집 Vol.2010 No.4

The presence of ultrasonic wave in caustic cleaning process enhances the remove pollutants, and more homogeneous, textured structure. The silicon wafers, cleaning in Deconex OF 145 solution (0.5~2wt %) with DIW under ultrasonic environment for 5 min. The presence of uniform thin layer of SiO2 on c-Si surface enhances etching rate in the caustic etching mixture solution of NaOH (1.5 wt %), DI water and IPA (6 wt %) at 90℃ for 20 min and results in a fine, more homogeneous and small textured structure.

반응표면분석법을 이용한 대추잎 항산화물질의 에탄올추출조건 최적화

민들레(Dul-Lae Min),임석원(Seokwon Lim),안준배(Jun-Bae Ahn),최영진(Young Jin Choi) 한국식품과학회 2010 한국식품과학회지 Vol.42 No.6

대추잎 항산화 물질의 고효율 추출을 위한 에탄올 용매추출조건을 반응표면분석법을 사용하여 최적화하였다. Box-Behnken design에 따라 추출공정 조작변수(온도, 시간, 에탄올 농도)를 독립변수로, 이에 따라 영향을 받는 종속변수(총 폴리페놀 함량, 총 플라보노이드 함량, 전자공여능)를 설정하여 실험하였다. 추출물의 총 폴리페놀 함량과 총 플라보노이드 함량은 시간과 온도의 영향을 거의 받지 않으며, 용매비가 높을수록 증가하다가 최고점을 보인 후 다시 감소하는 경향을 나타내었다. 전자공여능 또한 시간과 온도의 영향보다는 용매비에 영향을 많이 받는데, 에탄올 농도가 높을수록 전자공여능이 높게 측정되었다. 추출물의 특성을 모두 만족시키는 최적 추출조건 범위 내에서 임의의 조작조건(온도 45℃, 시간 15분, 에탄올 농도 45%)을 설정하였다. 최적조건에서 예측값과 실험값을 비교한 결과, 유사한 값을 보여주어 회귀식이 신뢰할 수 있음을 알 수 있었다. The leaves of Zizyphus jujuba have been used for various purposes including medicine and nutrition. In this study, the conditions for the ethanol extraction of antioxidant from Zizyphus jujuba were optimized using response surface methodology (RSM). A Box-Behnken design containing 15 experimental runs with three replicates was employed to study the effects of solvent extraction conditions such as extraction temperature (℃, X<SUB>1</SUB>), extraction time (min, X<SUB>2</SUB>), and ethanol concentration (%, X<SUB>3</SUB>) on the extraction yield of antioxidants from Zizyphus jujuba. The yields of total polyphenols and total flavonoid, and electron donating activity (EDA) were considered as response variables. The second-order polynomial model gave a satisfactory description of the experimental results showing different patterns of extraction conditions with variation in the linear, quadratic, and interaction effects of the independent variables. Based on four-dimensional RSM, one of the optimized sets of conditions was 45% ethanol, 45℃, and an extraction time of 15 min. Under the optimal conditions, the predicted values were 177.64 mg/g dry basis, 35.99 mg/g dry basis, and 86.14% Vit.C equivalents for total polyphenols, total flavonoids, and EDA, respectively. The experimental values showed good agreements with the predicted values.

고등어(Scomber japonicus ) 치어의 마취제로서 Clove oil, MS-222 및 2-Phenoxyethanol의 평가

한석중 ( Seock Jung Han ),김경민 ( Kyong Min Kim ),최낙중 ( Nack Jung Choi ),구준호 ( Jun Ho Koo ),박충국 ( Chung Kug Park ),이원교 ( Won Gyo Lee ),지승철 ( Seung Chul Ji ) 한국수산과학회(구 한국수산학회) 2011 한국수산과학회지 Vol.44 No.6

The efficiency of clove oil, MS-222, and 2-phenoxyethanol was evaluated as anesthetics in juvenile Scomber japonicus . Stage A5 of anesthesia was assumed to be sufficient for conducting routine aquaculture procedures in less than 3 min, with recovery (stage R5) in less than 5 min. The lowest effective doses of the three anesthetics were 50 mg L-1 clove oil (anesthetic time of 71.3 s and recovery time of 167.0 s), 100 mg L-1 MS-222 (anesthetic time of 70.7 s and recovery time of 115.7 s), and 400 mg L-1 2-phenoxyethanol (anesthetic time of 86.7 s and recovery time of 95.0 s). Anesthetic times decreased with increasing doses for all three anesthetic agents, and fish anesthetized with clove oil exhibited the longest recovery times. After 30 min, the highest plasma cortisol and lactate levels were detected with the use of clove oil, whereas the lowest values were observed with 2-phenoxyethanol. In addition, high glucose levels were maintained during recovery with clove oil, but the treatments did not significantly differ. The most effective of the three anesthetic agents was 2-phenoxyethanol, although all were considered acceptable for use in cultures of juvenile Scomber japonicus

CT사진을 이용한 한국인의 C형 치근관의 분포에 대한 연구

전록원,허경회,이원진,허민석,이삼선,최순철 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.2

Purpose : To investigate the incidence and prevalence of C-shaped root canal using computed tomographic images of head and neck in Korean population. Materials and Methods : Regardless of each examination purpose, randomly selected 268 examples which have serial axial computed tomographic images with 8 normal molars in maxilla and mandible were selected and investigated. Defined C-shaped root canal and we could get 82 proper image examples in view of this definition. These were detected and investigated of incidence and prevalence of C-shaped root canal. Results : C-shaped root canals were found in 82 examples among 268 (30.6%) and 147 teeth. They were only found on molar area, and the highest incidence was 37.41% of left mandibular second molars, and the lowest was 2.04%of right maxillary second molars. On prevalence of tooth position, mandibular second molar was the highest, 65% of C-shaped root canal teeth and maxillary second molar was 6% the lowest. Conclusion : 31% of randomly selected CT images no considering check-up reason have C-shaped root canals. The C-shaped root canals of mandibular second molar are found most frequently and they are also detectable on maxilla. On Korean population, C-shaped root canals are one of conditions that have to concern with dental treatment for it appears at a high prevalence relatively.