• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1869-1873
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• 2008

An isolate from holothurians was identified as an eicosapentaenoic acid (EPA)-producing bacterium KMG427, which is characterized by EPA synthesis efficiency, by thin layer and gas chromatographic analyses. The EPA production was maximized to more than 10% of the total fatty acids by incubation at $4^{\circ}C$ after cell proliferation at $20^{\circ}C$. The isolated bacterium was categorized as Gram-negative, rod-shaped, aerobic, and motile with a single polar flagellum. According to phylogenetic analysis based on morphological and physiological specificities as an EPA-producing bacterium, the isolate KMG427 was found to belong to the genus Shewanella. The 16S rDNA of KMG427 was revealed to have 100% of sequence identity to that of S. hanedai CIP $103207^T$. Therefore, the isolate might be classified and identified as Shewanella sp. KMG427.

• Journal of Life Science
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• v.14 no.2
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• pp.221-224
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• 2004

Comparisons of enzymatic method, gas chromatographic method, and the Iatroscan method for the determination of cholesterol in each parts of Korean squid were undertaken. The Iatroscan method was the most suitable procedure for the rapid and simple determination of net cholesterol concentration in parts of Korean squid. 5$\alpha$-cholestane is used as a good internal standard. The cholesterol contents in body, leg, viscera, eye, skin, and liver part of Korean squid, Todarodes pacificus STEEN STRUP by Iatroscan method were 178.9, 321.4, 168.9, 159.5, 608.8 and 634.2 mg%, respectively.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.248-254
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• 1990

Commercial food grade porcine-pancreatic lipase was incorporated into cheese at two different levels of concentration and ripened at $7^{\circ},\;13^{\circ}\;and\;21^{\circ}C$ Gas chromatographic analysis showed that the pancreatic lipase-treated cheese produced significantly higher levels of short-chain free fatty acids than controls. At $21^{\circ}C$ the high level of pancreatic lipase-treated cheese produced medium flavor cheese at 1 wk and close to sharp flavor cheese at 3 wk without causing distinctive defects. The low level of pancreatic lipase-treated cheese developed a number of good quality cheese. They were roughly equivalent to medium and sharp cheeses when ripened at $7^{\circ},\;13^{\circ}\;and\;21^{\circ}C$ for 3 to 15wk. Statistical analyses indicated that there were significant correlations between aged Cheddar flavor and the concentration of c6 as individual short chain free fatty acids (FFA) or C4 and C6 FFA combinations. Pancreatic lipase may be applicable for the accelerated ripening of Cheddar cheese if appropriate conditions are used.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.612-617
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• 1995

Changes in titratable acidity, pH, viable cells, sensory properties and volatile aroma compounds of yogurt during lactic fermentation in milk added with egg white powder (EWP) have been studied. Milk added with 1% or 2% (W/V) of EWP was fermented with Lactobacillus acidophilus for 30 hr. Acidity of milk added with EAT increased gradually during lactic fermentation for 30 hr, pH dropped gradually and number of viable cells increased and reached stationary phase at about 9 hr. Addition of EWP significantly stimulated acid production by lactic acid bacteria and stimulating effect of 2% EWP addition on acid production was slightly higher than that of 1% EWP addition. Sensory evaluation showed that optimum fermentation time of yogurt prepared from milk added with 2% of EWP was about 15 hr. Gas chromatographic analysis showed that the amount of acetone and butanol decreased gradually and that of ethanol increased until 30 hr. Diacetyl and acetoin were first detected after 6hr and 9hr, respectively, and then increased until 30 hr.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.458-463
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• 1995

A curd yogurt was prepared from milk added with skim milk powder or egg white powder(EWP). The effects of EWP addition on growth and acid production by lactic acid bacteria in milk were studied. The effects of EWP addition on quality of curd yogurt in point of apparent viscosity, sensory property and volatile aroma compounds were also investigated. Addition of PAT markedly stimulated acid production by lactic acid bacteria and stimulating effect of EWP on acid production was proportional to the amount of addition. Apparent viscosity of curd yogurt added with EWP was generally higher than that of control. Curd yogurt fermented with L. acidophilus showed thixotropic characteristics. Sensory property of curd yogurt added with EWP was evaluated as better than reference sample and sample added with EWP at 2% level was evaluated as better than other samples. Acetone, ethanol, diacetyl, butanol and acetoin were detected by gas chromatographic analysis.

• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.267-271
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• 2011

Static Headspace Gas Chromatographic analysis was used to study the partitioning behavior of five organic printing ink solvents between chocolate cookie/air systems. Three cookie sample formulations varied with respect to chocolate type and overall percentage of constituents. Major considerations involved differences in fat content and type and resulting variability in chemical and physical structure. Each of the solvents studied (ethyl acetate, hexane, isopropanol, methyl ethyl ketone, toluene) represents a general class of printing ink solvents based on predominate functional group. Values of the partitioning coefficient (Kp) were determined at equilibrium using measured quantities of both solvent and cookie sample in closed systems at temperature of 25, 35, and $45^{\circ}C$. In each of the three cookies at the three test temperatures, toluene always exhibited the greatest value of partitioning to cookie and hexane always exhibited the least. Results also showed that the partitioning behavior of solvents is generally inversely related to temperature and that solvent affinity, though constant for a particular cookie type over all test temperatures, varies significantly among the three cookie types. The preference of each of the five solvents for each cookie sample was also found to vary with temperature. No correlation was found between the extent of partitioning and cookie formulation or physical characteristic of solvent. The Hildebrand parameter, related to ${\Delta}Hmix$ (heat of mixing), may be used to describe differences in partitioning based on the overall potential of a solvent/cookie interaction to occur. The potential for interaction is dependent upon the chemical structure of the cookie sample and thus the availability of 'active-sites' required for a given solvent.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.553-558
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• 2012

A simple new method was developed for the determination of betaine in Fructus Lycii using hydrophilic interaction liquid chromatography with evaporative light scattering detection (HILIC-ELSD). Good chromatographic separation and reasonable betaine retention was achieved on a Kinetex HILIC column ($2.1{\times}100mm$, $2.6{\mu}m$) packed with fused-core particle. The mobile phase consisted of (A) acetonitrile and (B) 10 mM ammonium formate (pH 3.0)/acetonitrile (90/10, v/v). It was used with gradient elution at a flow rate of 0.7 mL/min. The column temperature was set at $27.5^{\circ}C$ and the injection volume was $10{\mu}L$. The ELSD drift tube temperature was $50^{\circ}C$ and the nebulizing gas (nitrogen) pressure was 3.0 bar. Stachydrine, a zwitterionic compound, was used as an internal standard. Calibration curve over $10-250{\mu}g/mL$ showed good linearity ($R^2$ > 0.9992) and betaine in the 70% methanol extract of Fructus Lycii was well separated from other peaks. Intraand inter-day precision ranged from 1.1 to 3.0% and from 2.4 to 5.3%, respectively, while intra- and inter-day accuracy ranged from 100.0 to 107.0% and from 94.3 to 103.9%, respectively. The limit of quantification (LOQ) was $10{\mu}g/mL$ and the recoveries were in the range of 98.2-102.7%. The developed HILIC-ELSD method was successfully applied to quantitatively determine the amount of betaine in fourteen Fructus Lycii samples from different locations, demonstrating that this method is simple, rapid, and suitable for the quality control of Fructus Lycii.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1121-1126
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• 2009

This paper describes a pattern recognition method of Magnoliae flos based on a gas chromatographic/mass spectrometric (GC/MS) analysis of the essential oil components. The botanical drug is mainly comprised of the four magnolia species (M. denudata, M. biondii, M. kobus, and M. liliflora) in Korea, although some other species are also being dealt with the drug. The GC/MS separation of the volatile components, which was extracted by the simultaneous distillation and extraction (SDE), was performed on a carbowax column (supelcowax 10; 30 m{\time}0.25 mm{\time}0.25{\mu}m$) using temperature programming. Variance in the retention times for all peaks of interests was within RSD 2% for repeated analyses (n = 9). Of the 74 essential oil components identified from the magnolia species, approximately 10 major components, which is $\alpha$-pinene, $\beta$-pinene, sabinene, myrcene, d-limonene, eucarlyptol (1,8-cineol), $\gamma$-terpinene, p-cymene, linalool, $\alpha$-terpineol, were commonly present in the four species. For statistical analysis, the original dataset was reduced to the 13 variables by Fisher criterion and factor analysis (FA). The essential oil patterns were processed by means of the multivariate statistical analysis including hierarchical cluster analysis (HCA), principal component analysis (PCA) and discriminant analysis (DA). All samples were divided into four groups with three principal components by PCA and according to the plant origins by HCA. Thirty-three samples (23 training sets and 10 test samples to be assessed) were correctly classified into the four groups predicted by PCA. This method would provide a practical strategy for assessing the authenticity or quality of the well-known herbal drug, Magnoliae flos.

• Analytical Science and Technology
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• v.34 no.3
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• pp.134-141
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• 2021

In this study, the fatty acid (FA) composition of commercial sesame oils (n = 62) was investigated using gas chromatography with flame ionization detector (GC-FID). Multivariate statistical techniques, including principal component analysis (PCA) and linear discriminant analysis (LDA), were applied to the chromatographic data of the FAs to discriminate the geographical origin of sesame oils. A statistically significant difference was observed in the content of C16:0, C18:0, C18:1, and C18:2 between domestic and imported sesame oils. A satisfactory recovery rate of 82.8-100.2 % was achieved for C16:0, C18:0, C18:1, C18:2, and C18:3. The correlation of C16:0, C18:1, and C18:2 in domestic sesame oils showed opposite trends compared to imported oils. The PCA plot demonstrated that sesame oils were clustered in distinct groups according to their origin. LDA was used to predict sesame oil samples in one of the two groups. C16:0 (Wilks λ = 0.361) and C18:1 (Wilks λ = 0.637) demonstrated the highest discriminant power for classifying the origin of the samples. The correct prediction rates were 88.9 % and 100 % for the domestic and imported samples, respectively. Further, 60 of the 62 sesame oil samples (96.8 %) were correctly classified, indicating that this approach can be used as a valuable tool to predict and classify the geographical origin of sesame oils.

• Korean Journal of Food Science and Technology
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• v.24 no.3
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• pp.272-278
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• 1992

Takju, a Korean traditional wine, was prepared by using nuruk and Koji which were inoculated with Aspergillus kawachii and Aspergillus shirousamii. Those chemical composition such as alcohols and organic acids were determined with gas chromatography to investigate the variation of its content by the fermentation. Alcohol such as methyl, ethyl, n-propyl, i-butyl, i-amyl alcohol were detected in the most takju mash samples. Alcohol contents in the groups fermented with KNR and SNR were slightly higher than KKR, SKR groups. Lactic acid were concentrated and organic acids such as pyruvic, oxalic, malonic, succinic, maleic, malic, ${\alpha}-keto$ glutaric acid were also detected in the most samples. The pH was lowest in the KKR group. The total acid content was slightly decreased at the later fermentation and was highest in KKR. The content of minerals were highest in the WNR and BNR groups. Throughout fermentation the content of potassium and magnesium varied greatly with the tested groups.