Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Sung Hee Park,Jae Hyeong Kim,Sang Gi Min,Yeon Ji Jo,Ji Yeon Chun 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water (170°C, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of ≤ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

Synthesis and biodistribution of 18F-labeled α-, β- and ω-fluorohexadecanoic acid

Yun-Sang Lee,Young Joo Kim,Gi Jeong Cheon,Jae Min Jeong 대한방사성의약품학회 2018 Journal of radiopharmaceuticals and molecular prob Vol.4 No.2

ω-[18F]-Fluorohexadecanoic acid (FHA) has been used for imaging of fatty acid metabolism of myocardium. To increase retention of radiolabeled fatty acid by blocking β-oxidation, methyl branched analogues have been used. In this experiment, we tried to synthesize 18F-labeled α-, β- and ω-FHA for imaging of the myocardial fatty acid metabolism. We synthesized α-, β- and ω-mesylated methyl hexadecanoates and labeled with 18F by reacting with [18F]TBAF in acetonitrile at 80ºC for 10 min. Methyl ester group was removed by 1 M NaOH at 80ºC for 5 min. The yields of α-[18F] and ω-[18F]FHA were 25.5 and 45.5%, respectively [EOS]. However, β-[18F] FHA was not labeled at all due to a fast elimination reaction. The biodistribution study in ICR-mice showed that ω-[18F]FHA has higher myocardial uptake and lower liver uptake than α-[18F]FHA. The electron-withdrawing effect of fluorine at α- position is believed to be the major factor affecting the biodistribution

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta

Park, Sung Hee,Kim, Jae-Hyeong,Min, Sang-Gi,Jo, Yeon-Ji,Chun, Ji-Yeon Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.2

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water ($170^{\circ}C$, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of $\leq$ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

제주 성상 S/S MTr #1 행원 풍력단지 전압해석

김상준(Sang-Jun Kim),조민호(Min-Ho Cho),윤기갑(Gi-Gab Yoon),장상옥(Sang-Ok Jang),안정식(Jeong-Shik Ahn) 대한전기학회 2003 대한전기학회 학술대회 논문집 Vol.2003 No.11

Synthesis and biodistribution of ¹⁸F-labeled α-, β- and ω-fluorohexadecanoic acid

Lee, Yun-Sang,Kim, Young Joo,Cheon, Gi Jeong,Jeong, Jae Min Korean Society of Radiopharmaceuticals and Molecul 2018 Journal of radiopharmaceuticals and molecular prob Vol.4 No.2

${\omega}-[^{18}F]$-Fluorohexadecanoic acid (FHA) has been used for imaging of fatty acid metabolism of myocardium. To increase retention of radiolabeled fatty acid by blocking ${\beta}$-oxidation, methyl branched analogues have been used. In this experiment, we tried to synthesize 18F-labeled ${\alpha}-$, ${\beta}-$ and ${\omega}-FHA$ for imaging of the myocardial fatty acid metabolism. We synthesized ${\alpha}-$, ${\beta}-$ and ${\omega}$-mesylated methyl hexadecanoates and labeled with $^{18}F$ by reacting with $[^{18}F]$TBAF in acetonitrile at $80^{\circ}C$ for 10 min. Methyl ester group was removed by 1 M NaOH at $80^{\circ}C$ for 5 min. The yields of ${\alpha}-[^{18}F]$ and ${\omega}-[^{18}F]FHA$ were 25.5 and 45.5%, respectively [EOS]. However, ${\beta}-[^{18}F]FHA$ was not labeled at all due to a fast elimination reaction. The biodistribution study in ICR-mice showed that ${\omega}-[^{18}F]FHA$ has higher myocardial uptake and lower liver uptake than ${\alpha}-[^{18}F]FHA$. The electron-withdrawing effect of fluorine at ${\alpha}-$ position is believed to be the major factor affecting the biodistribution.

Research Articles : Quality Characteristics of Frozen Beef Developed into Home Meal Replacement Products Under Various Storage Conditions

( Sangyoon Lee ),( Kwang Il Kim ),( In Guk Hwang ),( Seon Mi Yu ),( Sang Gi Min ),( Mi Jung Choi ) 한국산업식품공학회 2015 산업 식품공학 Vol.19 No.3

Blanching and freezing of beef are important techniques used in developing frozen home meal replacement (HMR) products. These pre-thermal treatments minimize the deterioration of beef during storage. Beefs are washed, defatted, sliced (5.0×0.5×0.5 cm, fiber direction), and blanched by immersion in hot water for 2 min. Thereafter, the blanched beefs are spin-dried and frozen by individual quick freezing (IQF) method. Finally, the frozen beefs are packed using two methods: vacuum packages and air-containing packages. Packed beefs are stored at -12℃, -18℃, and -24℃ for nine months. One in every three months, they are thawed in a microwave (400W). While thawing, vacuum- packed samples possess lower thawing loss than air-containing-packed ones. Compared to raw beef, blanched beef have a higher L* and lower a* value. However, less changes are observed after blanching the beefs as the enzymes get inactivated in the blanching process. Shear force of beef also increase through blanching. Moreover, vacuum-packed samples have maintained their hardness to a greater extent than the air-containing-packed samples. All the samples have met microbial safety standards. Thus, it is inferred that vacuum-packaging and -18℃ storage temperatures are the best condition for maintaining beef that is later developed into HMR product.

열처리 방법에 따른 표고버섯의 이화학적 특성 및 영양학적 분석

이중규(Jung-Gyu Lee),김광일(Kwang-Il Kim),황인국(In-Guk Hwang),유선미(Seon-Mi Yoo),민상기(Sang-Gi Min),최미정(Mi-Jung Choi) 한국식품영양과학회 2015 한국식품영양과학회지 Vol.44 No.6

본 연구는 열수 침지, 증기 및 볶음 처리가 표고버섯에 미치는 이화학적 분석 및 영양성분 분석을 통해 최적 열처리 조건을 확립하고자 진행하였다. 소비자들이 상품을 평가할 때 1차적으로 먼저 관찰되는 색도와 경도를 측정하고 추가로 pH 측정 등으로 인한 이화학적 결과로 최적 조건을 선정한 뒤에 그 조건들에 대해서 영양학적 및 미생물 검사를 실시하였다. 색도는 열처리 시간이 길어질수록 색의 변색 정도가 증가하여 뚜렷한 차이를 나타내었다. pH 값은 열수 침지 처리의 경우 pH 증가량이 가장 높았으며 처리 시간이 지속될수록 pH가 증가하는 경향을 나타내었다. 다른 처리군의 경우 일정 시간의 처리 시간 이후에는 유의적인 차이를 보이지 않았다. 경도에서는 열수 침지와 볶음 처리의 경우 1분 이내의 열처리만으로도 경도가 감소하는 경향을 보였으며, 증기처리의 경우 1분 동안 경도가 유지되는 결과를 보였다. 일반성분 분석 결과는 증기 처리가 가장 원물에 가까운 결과를 나타냈다. 유기산 함량은 증기 처리에서 유기산 함량 감소율이 가장 낮았다. 또한 3분간 증기 처리를 하였을 때 미생물의 사멸 효과가 가장 높았다. 열수 침지 처리나 볶음 처리의 경우 전체적으로 증기 처리한 시료에 비해서 영양성분 함량이 줄어드는 경향을 나타냈다. 따라서 표고버섯을 증기 처리방법으로 열처리하는 것이 다른 열처리군에 비해서 최적으로 나타났다. 하지만 본 연구에서는 물리화학 및 영양학적 성분의 변화만을 분석하였기 때문에 실제 식품 산업이나 공정에 적용하기 위해서는 대용량 처리 시에 발생하는 문제들과 관련된 추가적인 연구를 필요로 할 것이다. In the food industry, thermal treatment is an important process for extending shelf-life of foods. However, heating process affects the physicochemical, nutritional, and microbial properties of foodstuff such as color, texture, pH, and proximate compositions. This study was conducted to select an optimal thermal treatment by observing physicochemical, nutritional, and microbial effects of shiitake mushrooms with different thermal treatment methods. Shiitake mushrooms were washed and sliced equally (5 cm×0.5 cm×0.5 cm) and then heat-treated by three methods. Samples were heated in 100°C boiling water, steamed for 10 min, or pan fried at 130°C for 4 min. Total color difference values showed significantly increasing tendency with treatment time. For pH values, boiling water-treated mushrooms showed increasing tendency according to increased thermal treatment. For the results of hardness, boiling water or pan frying-treated mushrooms showed reduced tendency within 1 min. In the case of steam-treated mushrooms, hardness values were maintained for 1 min. Organic acid contents of steam-treated sample showed the lowest value among treatments. For microbial counts, steam-treated samples for 3 min showed the lowest value. Consequently, the results of this study suggest that steam treatment could be the optimal thermal treatment to minimize quality loss of shiitake mushrooms.

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

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.

다양한 전처리 방법에 따른 양파의 이화학 및 영양학적 특성 분석

김광일 ( Kwang Il Kim ),황인국 ( In Guk Hwang ),유선미 ( Seon Mi Yu ),민상기 ( Sang Gi Min ),이상윤 ( Sang Yoon Lee ),최미정 ( Mi Jung Cho ) 한국산업식품공학회 2014 산업 식품공학 Vol.18 No.4

The pre-thermal treatment, or blanching, is an important process to minimize quality changes during main cooking or storage. In this study, three types of pre-thermal treatments were applied to onions to observe quality changes in their physicochemical, nutritional, and microbial properties. The washed and sliced onions were treated by hot-water immersion (100oC, 1~10 min), steaming (100oC, 1~10 min) and stir-frying with oil (180oC, 10~80 sec). The onions were cooled and wiped with gauze. The results showed that the total color difference of the treated sample increased to 18-23 units compared to that of the fresh control. The pH value of the onion was not significantly different with the exception of the stir-fried samples. The hardness of the onion tended to decrease depending on the treatment time. The micro-structures of onions treated by hot-water immersion and steaming were damaged above 2 min whereas stir-fried onions showed structural damage above 210 sec. In the analysis of the nutritional changes in the onion, the ascorbic acid content of the blanched treatments were lower than that of fresh onion and the free sugar contests showed a similar pattern excluding the stir-fried onions. In the organic acid content assay, the succinic acid content of the treated onion sample had significantly decreased compared with other organic acid contents (p<0.05). The peroxidase activities of the blanched treatments by hot-water immersion and steaming were inactivated by more than 92%, whereas only 76% inactivity was achieved by the stir-frying treatment. The mesophilic and psychrotrophic bacteria counts of the treated onion were not detected or decreased to near a 3-log scale, and yeast was detected only the sample treated by the stir-frying for 1 min. In particular, neither bacteria nor yeast counts in all onion samples by steam treatment were detected. Consequently, the results demonstrated that steam treatment for 2 min could be the optimal pre-thermal condition for onions to minimize the quality changes and increase safety.

Relationship between Occupational Stress and Work-related Musculoskeletal Disorders in Korean Male Firefighters

Min Gi Kim,Kyoo-Sang Kim,Jae-Hong Ryoo,Seung-Won Yoo 대한직업환경의학회 2013 대한직업환경의학회지 Vol.25 No.-

Objectives: A growing body of literature has documented that job stress is associated with the development of work-related musculoskeletal disorders (WMSDs). However, the association of WMSDs with job stress has not yet been fully studied in Korean male firefighters. The purpose of this study was to determine the status of WMSDs in almost all Korean male firefighters and to clarify the effect of job stress on the occurrence of WMSDs. Methods: The study design was cross-sectional, and 21,466 firefighters were recruited. The study design included a structured questionnaire to assess general characteristics, the Korean Occupational Stress Scale (optional KOSS-26), Center for Epidemiologic Studies-Depression Scale (CES-D), and WMSDs. The chi-square test, and univariate and multivariate logistic regression analyses were used to look for a correlation between general characteristics and job stress, and the occurrence of WMSD. Results: Back pain is the most common WMSD. Among the job stress subgroup, physical environment, job demands, organizational system, occupational climate, lack of reward and job insecurity were related to the occurrence of WMSDs. However, insufficient job control and interpersonal conflict were not related to the occurrence of WMSDs. Conclusion: Job stress was related to the occurrence of WMSDs in Korean male firefighters. To reduce the occurrence of WMSDs, a job stress management program may be required.