• 농업과학연구
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• 제39권3호
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• pp.377-386
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• 2012

To reduce the saturation level of lard, solvent fractionation with hexane and acetone was carried out. The fatty acid compositions of lard were 1.5% myristic acid, 26.0% palmitic acid, 2.2%, palmitoleic acid, 12.1% stearic acid, 44.7% oleic acid, and 12.7% linoleic acid. Lard was fractionated by various conditions such as different fractionation temperatures (-15, 5, 10, $15^{\circ}C$), solvent ratios (1:1, 1:3, 1:5, 1:10, lard : solvent, w/v), and fractionation time (3, 6, 24 hr). At $-15^{\circ}C$, acetone was better for reducing the content (11.2%) of saturated fatty acids (SFA) than hexane (10.8%) when the 1:5 solvent ratio was used at 24 hr. Triacylglycerol (TAG) profiles were analyzed by reversed-phase high performance liquid chromatography based on the partition number (PN) of TAG molecules. The PN of major TAG species in lard were 46 (24.4%), 48 (55.7%), and 50 (19.9%). However, after fractionation (1:5, $5^{\circ}C$ and 24 hr), TAG species with a PN of 46 (34.2%), 48 (54.4%), and 50 (6.9%) were major components in acetone-fractionated lard (liquid part), while TAG species with a PN of 46 (26.0%), 48 (50.3%), and 50 (19.0%) were in hexane-fractionated lard, suggesting that fractionation with acetone resulted in maximal reduction of saturation level in lard.

• KSBB Journal
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• 제21권5호
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• pp.366-370
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• 2006

UDP-glucose는 ${\beta}$-1,3-glucan 합성의 중요한 전구체로 이를 측정함으로써 세포 내의 glucan synthesis 대사의 활성도를 추정할 수 있는 중요한 지표가 됨을 본 연구 결과를 통하여 알 수 있었다. UDP-glucose는 세포 성장기에 다량 생산되다가 ${\beta}$-1,3-glucan 합성하는 시기에 일정한 농도가 되며 ${\beta}$-1,3-Glucan 합성 메카니즘에서 glucose를 운반하는 중요한 역할을 하는 것으로 나타났다. 2단 연속 발효조를 이용하여 세포 성장 발효조와 ${\beta}$-1,3-glucan 생산 발효조에서 UDP-glucose 변화를 관찰하여 ${\beta}$-1,3-glucan 생산시 농도가 높음을 관찰할 수 있었다. ${\beta}$-1,3-Glucan 생산 발효조의 pH를 5.5로 조절함으로써 UDP-glucose의 농도를 증가시킬 수 있을 뿐만 아니라 ${\beta}$-1,3-glucan의 생산 속도를 최적화할 수 있었다.

• 한국환경보건학회지
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• 제22권1호
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• pp.36-44
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• 1996

A comparison was made of two detection methods(UV absorbence detection and fluorescence detection with pre-column derivatization, with trifluoroacetic acid) coupled with HPLC for the simultaneous determination of aflatoxin $B_1, B_2, G_1$ and $G_2$. A good separation of the four aflatoxins was achieved on a reversed-phase $C_{18}$ column (30 cm x 3.9 mm) with methanol-acetonitrile-water(20+20+60) for absorbence detection or acetonitrile-water(25+75) for fluorescence detection at the flow rate of 1.0 ml/min. The calibration graphs were linear over the ranges 100 ppb-1 ppm for $B_1/G_1$ and 30~300 ppb for $B_2/G_1$ with absorbence detection, and 1~500 ppb for $B_1/G_1$ and 0.3~150 ppb for $B_2/G_2$ with fluorescence detection. The correlation coefficients were greater than 0.94 and 0.99 for absorbance detection and for fluorescence detection, respectively. The detection limit was 100 ng for $B_1/G_1$ and 30 ng for $B_2/G_2$ with absorbence detection, and 1 ng for $B_1/G_1$ and 0.3 ng for $B_2/G_2$ with fluorescence detection. Recovery rates of aflatoxin $B_1, B_2, G_1$ and $G_2$ added to yeast-extract sucrose broth medium were 66.6%, 59.4%, 67.5% and 59.2%, respectively, for absorbence detection and 82.9%, 71.5%, 80.0% and 69.3%, respectively, for fluorescence detection. The four aflatoxins in culture medium were quantitatively detected by the two methods. The aflatoxins in the rice sample were not detected the absorbence detection method, but were below 10 ppb using the fluorescence detection method. Analysis of aflatoxins by both the absorbence and fluorescence methods coupled with HPLC showed acceptable linearity and good recovery. The absorbence detection was less timeconsuming and safer for treatment. The fluorescence detection was more elective and sensitive though elevated $B_1$ and $G_1$ contents were determined from the TFA-induced conversion of $B_1$ to $B_{2a}$ and $G_1$ to $G_{2a}$.

• KSBB Journal
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• 제15권3호
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• pp.238-242
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• 2000

Enterokinase에 의한 G3-IL-2 가수분해 반응에 있어서의 urea 는 글루카곤과 IL-2를 분리하고자 하는 데에 펼요한 절단 부위 가 잘 노출되도록 도움을 주는 역할을 하는데 1.0 M이상의 높 은 농도에서 오히려 원하는 단백질의 변성에 영향을 미침을 알 수 있었다, 그리고 효소 반응 시에 효소의 활성에 도움을 주는 첨가제는 반응 후에 침전이 생기고, IL-2의 회수율에는 오히려 나쁜 영향을 주었다. 그리고 반응시간에 따른 반응의 효과는 24 시간 이후에는 효소에 의한 가수분해 반응이 진행되지 않음이 관찰되었다. 가수분해 반응 후의 순수한 IL-2의 회수율은 약 1 5 5~35% 정도였고, 반응 조건에 따라 수융은 차이가 있었다. IL-2는 시간이 지남에 따라 분자 상호 간의 응집에 의해 oligomer의 형태가 되어 본래의 크기보다 더 커져 RP-HPLC에서 더 빨리 용리되는 결과를 얻을 수 있었다.

• 한국생산제조학회지
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• 제21권2호
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• pp.267-275
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• 2012

Austenite stainless steel 304 has properties of high resistance to corrosion and temperature changes. Therefore, this material is widely used in various of industries. However, when the material is subjected to heating and cooling cycles the forming accuracy, for example, the right angle associated with a sharp bend such as corner is lost. This phenomenon is caused by the reversion of the deformation-induced martensite into austenite when the temperature in increased. This result in misfit of a structure or an assembly, and an increase in residual stress. Hence, it is important to understand this process. In this study, to evaluate the mechanical behavior of the deformation-induced martensite and reversed austenite, a scanning acoustic spectroscope including the capability of obtaining both phase and amplitude of the ultrasonic wave (i.e., the complex V(z) curve method) was used. Then, the velocities of the SAW propagating within the specimens made in different conditions were measured. The experimental differences of the SAW velocities obtained in this experiment were ranging from 2,750 m/s to 2,850 m/s, and the theoretical difference was 3.6% under the assumption that the SAW velocity was 2,800 m/s. The error became smaller as the martensite content was increased. Therefore, the SAW velocity may be a probe to estimate the marternsite content.

• Food Science and Biotechnology
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• 제17권5호
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• pp.1097-1101
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• 2008

The objective of this study was to identify and quantify glucosinolates (GSLs) in Brassica napus cv. Hanakkori and its parents and to evaluate its potential bitter taste. 'Hanakkori' materials were cultivated with commercial chemical nutrients (20 kg/ha, N-P-K: 16-10-10) at the field. GSLs were isolated by means of extraction with 70%(v/v) boiling methanol (MeOH) followed by desulfation from those plants by reversed-phase high performance liquid chromatography (HPLC) and identified by electronic spray ionization-mass spectrometry (ESI-MS) analysis. In 'Hanakkori', 11 GSLs were identified as progoitrin, glucoraphanin, glucoalyssin, gluconapoleiferin, gluconapin, 1-methylpropyl, glucobrassicanapin, glucobrassicin, 4-methoxyglucobrassicin, gluconasturtiin, and neoglucobrassicin. The total GSL contents were 109 and 36.1 mmol/kg dry weights (d.w.) for the seeds and edible parts, respectively. The major GSLs (>5 mmol/kg d.w.) in the seeds were progoitrin (78.8), gluconapin (10.7), and glucobrassicanapin (7.81), whereas they in the edible parts were progoitrin (16.1) and glucobrassicanapin (8.58). In addition, the bitter taste in the edible parts was presumably related with the presence of progoitrin (>45% to the total GSL).

• 한국식품과학회지
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• 제33권4호
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• pp.416-422
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• 2001

식품포장용 PVC제인 wrap, sheet 및 gasket으로부터 식품 유사용매와 식품으로 이행되는 알킬페놀류를 HPLC와 GC/MSD로 분석하였다. 세 가지 모든 재질에서 7개의 nonyl phenol 이성질체만이 검출되었고 다른 알킬페놀류는 검출되지 않았으며, wrap이 sheet와 gasket보다 그 함량이 높았다. 각 포장재질로부터 수용성 식품유사용매(증류수, 4% acetic acid, 20% ethanol)와 지용성 식품유사용매(n-heptane)에 의한 nonyl phenol의 용출량은 처리온도 $60^{\circ}C$보다는 $95^{\circ}C$에서, 수용성보다는 지용성 식품유사용매에서 각각 많았고, 또한 wrap에서 sheet와 gasket보다 그 양이 많았다. PVC gasket을 사용한 과일쥬스, olefin계 gasket을 사용한 유아용 쥬스, olefin계 병마개를 사용한 음료에서 nonyl phenol이 각각 포장재로부터 이행되었으며, 포장하기 전의 이들 식품에서도 nonyl phenol이 검출되었다.

• 한국식품과학회지
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• 제36권4호
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• pp.537-541
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• 2004

1-L stirred-batch type reactor에서 기질들의 몰 비율을 1:2:2(corn oil:capric acid:CLA)하고 RM IM lipase을 사용하여 재구성 지질을 합성하였다. 합성된 재구성 지질은 총 capric acid 와 CLA을 각각 13.3 mol%와 8.9 mol% 함유하였다. 기능성 지방산은 주로 sn-1,3 position에 분포하였고, sn-2 position에는 linoleic acid가 대부분이었다. 재구성 지질의 요오드가와 비누화가는 68과 202이었고, 이는 재구성 지질에 함유된 capric acid 때문이었다. 반응 후 재구성 지질의 총 tocopherol 함량은 약 39% 감소하였다. 색도분석결과, 재구성 지질과 옥배유 서로간에 백색도$(L^*)$와 적색도$(a^*)$에서는 유의적 차이가 없었으나, 황색도$(b^*)$에서는 재구성 지질이 옥배유보다 yellowness를 보이며 유의적 차이를 보였다(p<0.05). RP-HPLC 분석결과 재구성 지질에서 capric acid를 함유하고 있는 TAG형태의 PN은 26-44로 전체의 약 34.2 area% 차지함을 알 수 있었다. 또한 옥배유가 $-56.77^{\circ}C$에서 주된 crystallization peak 정점을 보인 반면에, 재구성 지질은 $-46.2^{\circ}C$에서 주된 peak 정점을 나타내었다.

• 한국대기환경학회지
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• 제23권1호
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• pp.39-49
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• 2007

In this study, the performance characteristics of solid phase microextraction (SPME) were investigated for three major odorous groups that consist of 10 individual compounds ([1] volatile organic compounds (VOC): benzene, toluene, p-xylene and styrene, [2] reduced sulfur compounds (RSC): hydrogen sulfide, methyl mercaptan, dimethylsulfide (DMS), dimethyldisulfide (DMDS), and carbon disulfide, and [3] amine: trimethylamine (TMA)). For the purpose of a comparative analysis, two types of SPME fiber ([1] polidimethylsiloxane/divinilbenzene (P/D) and [2] $Carboxen^{TM}$/polidimethylsiloxane (C/P)) were test ε d against each other for a series of standards prepared at different concentration levels (100, 200, and 500 ppb). To compare the analytical performance of each fiber, all standards were analyzed for the acquisition of calibration data sets for each compound. The results of P/D fiber generally showed that its calibration slope increased as a function of molecular weight across different VOCs; however, those of C/P fiber showed a fairly reversed trend. Besides, we confirmed that the application of SPME is limited to many sulfur compounds; only two compounds (DMS and DMDS) are sensitive enough to draw calibration results out of SPME. The calibration data for RSC show generally enhanced slop values for C/P relative to P/D fiber. However, in the case of TMA, we were not able to find a notable difference in their performance.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.135-138
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• 2004

In order to find potential anticancer agents, we extracted pheophytin from silkworm feces according to various dry and storage methods such as sun dry, shade dry, fresh freezing dry and freezing dry after freezing storage (for 1∼3 years). The pheophytin extracts, mainly 10-hydroxypheophytin a, little b, of various storage silkworm feces were analyzed by reversed-phase high-performance liquid chromatography with photodiode array and fluorescence detection. The content of those pheophytih in old silkworm for 3 years (freezing storage and freezing dried in use, or freezing dried and cold storage) was better than others. The cytotoxicity of the pheophytin extracts and ethanol extracts of various storage silkworm feces were measured using Jurkat cells originated from human leukemia, using dye uptake assay (MTT) in order to find effective photodynamic therapeutic agents. The anticancer activity of those pheophytin extracts in various storage methods showed little difference among them. But ethanol extracts of fresh freezing dried silkworm in the current year was good cytotoxic activity than those of any other silkworm feces. With regards to these results, fresh ethanol extracts of silkworm feces were better than old ones. On the other hands, the pheophytin extracts of old silkworm feces contained the highest percentage of pheophytin content and showed good cytotoxicity against cancer cells by changing the pheophytin into pheophobide in the degradative process.