• Korean Journal of Agricultural Science
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• v.39 no.3
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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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• v.21 no.5
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• pp.366-370
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• 2006

In this research, analysis of UDP-glucose a precursor of ${\beta}$-1,3-glucan by high performance liquid chromatography(HPLC) was established using a reversed phase system. One of key metabolite UDP-glucose was selected and its concentration changes was measured with the change of fermentation conditions. The effects of fermentation conditions with/without nitrogen source for cell growth on ${\beta}$-1,3-glucan production were dependent on the UDP-glucose concentration. The UDP-glucose was synthesized rapidly during cell exponential growth period and maintained high during ${\beta}$-1,3-glucan production period. The UDP-glucose concentration was higher for ${\beta}$-1.3-glucan production fermentor than that for cell growth fermentor. The ${\beta}$-1,3-glucan production was optimal at pH 5.5 and synthesis of ${\beta}$-1,3-glucan was greatest at pH 5.5.

• Journal of Environmental Health Sciences
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• v.22 no.1
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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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• v.15 no.3
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• pp.238-242
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• 2000

A fusion protein of human interleukin-2(hiL-2) and glucagon which was expressed in Escherichia coli. was digested with enterokinase for recovery of hIL-2 from the fused protein. To obtain hIL-2 of optimum recovery hydrolysis reaction were performed under various conditions of urea additives and reaction time. hIL-2 was finally purified by RP-HPLC(reversed phase-HPLC) to remove cleaved G3 fusion partner and residual uncleaved G3-IL-2 HIL-2 was eluted in a single peak at 100% acetonitrile at 28 min. Optimum urea concentration was found to be 0.5 M and 24 h reaction time was sufficient without any additive such as CaCl2 and Tween-20.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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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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• v.17 no.5
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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).

• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.416-422
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• 2001

The migration of alkylphenols from PVC packaging materials (wrap, sheet and gasket) into food simulants and foods were analyzed by reversed-phase high-performance liquid chromatography with fluorescence detection and gas chromatography with mass selective detection. Only seven nonyl phenol isomers were detected in three types of PVC food packaging materials and the content of nonyl phenol of wrap was higher than those of sheet and gasket. The contents of nonyl phenol migrated from fatty food simulants (n-heptane) were higher than those from aqeous food simulants (distilled water, 4% acetic acid and 20% ethanol) and increased with increase in temperature. Nonyl phenol in fruit juice, infant formula, and beverage was migrated from PVC gasket, olefin gasket, and olefin bottle cap, respectively. Nonyl phenol was also detected from foods even before contacting with the packaging materals.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.537-541
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• 2004

Based on reaction time and substrate molar ratio, structured lipid (SL-corn) was produced at 1:2:2(corn oil/capric acid/CLA) and 4% immobilized lipase from Rhizomucor miehei (RM IM). Reaction was carried out for 24 hr at $55^{\circ}C$ in 1-L stirred-batch reactor. After reaction, 13.3 mol% capric acid and 8.9%, CLA were incorporated into corn oil. Iodine and saponification values of SL-corn were 68 and 202, respectively. Tocopherol content decreased after reaction (about 39%). SL-corn showed more yellowish color than corn oil (p<0.05). Reversed-phase HPLC indicated triacylglycerol species containing capric acid in SL-corn resulted in faster crystallization than that of corn oil.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.1
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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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• v.8 no.2
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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.