• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.9
• /
• pp.1529-1536
• /
• 2004

This study was designed to determine total trans fatty acids (tFAs) content of processed foods commonly consumed in the Korean diet and to prepare the database for the estimation of tFAs intake in Koreans. Total fat and tFAs content was determined by Soxhlet extraction method and attenuated total reflection infrared spectroscopy (ATR-IR), respectively. The tFAs positional isomers were analyzed using GC/MS spectrometer. In margarines, the content of tFAs ranged from 8.27% to 28.53%. Shortenings contained higher levels of tFAs (1.98~11.33%) than lards (1.83~1.96%). The content of tFAs in grilled confectioneries was wide (7.37~26.54%). Instant popcorns contained the highest amount of tFAs. Fried chickens had 0.44 to 14.85% of tFAs and french fries had 5.18 to 27.01% of tFAs. In fried snacks (crispy) and chocolates, tFAs were not detected. The amount of tFAs per serving size was the highest in instant popcorn, followed by french fries, fried snack (tortilla), doughnuts, and grilled confectioneries. TFAs isomer of margarines was mostly C18:1${\Delta}$9t. In shortenings and lards, the most abundant positional isomer of tFAs was C18:1${\Delta}$9t and C18:2${\Delta}$9t ${\Delta}$12t. Correlation coefficient of tFAs content between IR and GC/MS method was $r^2$=0.91.

• Korean journal of food and cookery science
• /
• v.13 no.4
• /
• pp.422-426
• /
• 1997

Fresh broccoli is known to have the highest content of sulforaphane (S-methylsulfinylbutyl isothiocyanate) among all vegetables. Since isothiocyanates are formed from myrosinase-catalyzed hydrolysis of glucosinolates during tissue destruction of broccoli, the formation of sulforaphane in the extract of broccoli was examined under various processing conditions. The amount of sulforaphane in processed broccoli was measured using GC/MS analysis. Among fresh, dried, and boiled broccoli fresh broccoli exhibited the highest content of sulforaphane. Sulforaphane was maximally produced from the homogenate in 0.1 M phosphate buffer containing 1 mM Vitamin C stored at room temperature for 1 hr. In boiled broccoli, the amount of sulforaphane decreased as the boiling time increased, and reached to 10% of control after 30 min boiling. The amount of sulforaphane was decreased remarkably in dried broccoli in which freeze-dried and heat-dried broccoli had about 50% and 30％ of fresh ones, respectively.

• Journal of the Mineralogical Society of Korea
• /
• v.15 no.1
• /
• pp.22-32
• /
• 2002

Mineral composition and chemistry of the clay minerals in the three cores from the continental shelves of South Shetland Islands (NCS09) and Anberse Island (GC98-2), and from the fjord of King George Island (A10-01) were determined by X-ray diffraction and electron microprobe analysis in search of the distributions and origin of the clay minerals in the Antarctic marine sediments. Smectite content is relatively high in NCS09 regardless of core depths (av. 8.3%), but low in GC98-2 (1.1%). In Al0-01, smectite content is higher in the upper section than in the lower section. Kaolinite was not detected from all the cores in this study Yellow to yellowish green clay granules were commonly scattered in the sediments of NCS09 cores. The clays contain 16.97% and 2.53% $Fe_2$$O_3$와 $K_2$O. Average structural formula of the clay indicates ferrian beidellite . The (Fe, K)-rich smectite of NSC09 must have been derived from relatively young basaltic volcanics altered by reaction with seawater near Shetland Islands by glacial erosion or eolian process related to volcanic eruption. GC98-2 nearer to Antarctic continent is very low in smectite content. In A10-01, the lower diamicton was deposited from the glacial erosion of smectite-free ancient volcanics in the interior of King George Island, while the upper section was derived from the smectite-bearing terrestrial debris and eolian materials after retreat of glaciers in Marian Cove and ice cover in Barton Peninsula. Thehigh K contents of smectites suggest the interstratification of illite and smectite layers, which might be observed by future TEM lattice fringe imaging.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.3
• /
• pp.316-325
• /
• 2012

Xylanase has been used extensively in the industrial and agricultural fields. However, the low-yield production of xylanase from native species cannot meet the increasing demand of the market. Therefore, improving the heterologous expression of xylanase through basic gene optimization may help to overcome the shortage. In this study, we synthesized a high-GC-content native sequence of the thermostable xylanase gene xynB from Streptomyces olivaceoviridis A1 and, also designed a slightly AT-biased sequence with codons completely optimized to be favorable to Pichia pastoris. The comparison of the sequences' expression efficiencies in P. pastoris X33 was determined through the detection of single-copy-number integrants, which were quantified using qPCR. Surprisingly, the high GC content did not appear to be detrimental to the heterologous expression of xynB in yeast, whereas the optimized sequence, with its extremely skewed codon usage, exhibited more abundant accumulation of synthesized recombinant proteins in the yeast cell, but an approximately 30% reduction of the secretion level, deduced from the enzymatic activity assay. In this study, we developed a more accurate method for comparing the expression levels of individual yeast transformants. Moreover, our results provide a practical example for further investigation of what constitutes a rational design strategy for a heterologously expressed and secreted protein.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.55 no.3
• /
• pp.200-206
• /
• 2010

Banaba, Lagerstroemia speciosa (L.) Pers. (Lythraceae) is a tree that grows in the tropic islands of the Pacific. This plants are used for medical purposes in the world. The components of L. speciosa were analyzed for the contents according to growing stages at leaves. The distributions of the corosolic acid ($2{\alpha}$, $3{\beta}$-dihydroxyurs-12-en-28-oic acid), phytol, campestrol, and vitamin E were rich among samples in this study. These were contained much fatty acids. The mean content of palmitic acid was from 2.4% across all growing stages, varying from 2.15% for young leaves with the lowest content and 2.86% for fallen leaves with the highest content. Oleic acid, linoleic acid, and linolenic acid were contained nearly mean 2.0% in all leaves of banaba. Our results have shown that the phytochemical profile of young L. speciosa leaves differs quite radically from that of old L. speciosa leaves. In addition, these subdividing results according to plant growth should allow future researches to conduct targeted experimental studies and use of particular medical components of interest, examining chemical variation on the inter-developmental levels.

• Nuclear Engineering and Technology
• /
• v.49 no.4
• /
• pp.873-880
• /
• 2017

To identify the feasibility of disposing of spent activated carbon as a clearance level waste, we performed characterization of radioactive pollution for spent activated carbon through radioisotope analysis; results showed that the C-14 concentrations of about half of the spent activated carbon samples taken from Korean NPPs exceeded the clearance level limit. In this situation, we selected thermal treatment technology to remove C-14 and analyzed the moisture content and thermal characteristics. The results of the moisture content analysis showed that the moisture content of the spent activated carbon is in the range of 1.2-23.9 wt% depending on the operation and storage conditions. The results of TGA indicated that most of the spent activated carbon lost weight in 3 temperature ranges. Through py-GC/MS analysis based on the result of TGA, we found that activated carbon loses weight rapidly with moisture desorption reaching to $100^{\circ}C$ and desorbs various organic and inorganic carbon compounds reaching to $200^{\circ}C$. The result of pyrolysis analysis showed that the experiment of C-14 desorption using thermal treatment technology requires at least 3 steps of heat treatment, including a heat treatment at high temperature over $850^{\circ}C$, in order to reduce the C-14 concentration below the clearance level.

• Applied Biological Chemistry
• /
• v.37 no.1
• /
• pp.30-36
• /
• 1994

The essential oil of Schizandrae Fructus was extracted by simultanous distillation-extraction and steam distillation and analyzed by GC and GC-MS. The oil content of Schizandrae Frutus was 0.64% when extracted by steam distillation and 0.88% in case of simultanous distillation extraction and sensory analysis of the oil indicated woody, camphorous, spicy and sour characteristic notes. The experimental results confirmed the presence 47 volatile components, the major components were ${\gamma}-terpinene$, p-cymene, ${\alpha}-ylangne$ and ${\beta}-elemene$. The oil was fractioned into ten fractions and 4 fraction of them have a good aroma character. The application of the oil showed the utilization possibility as flavoring materials for Korea tea.

• Applied Biological Chemistry
• /
• v.37 no.1
• /
• pp.37-42
• /
• 1994

The essential oil of Artemisia apiaceae Hence was extracted by simultanous distillation-extraction and steam distillation and analyzed by GC and GC-MS. The oil content of Artemisia apiaceae Hance was 0.23% when extracted by steam distillation and 0.37% in case of simultaneous distillation-extraction and sensory analysis of the oil indicated camphorous and herbal characteristic notes. the experimental results confirmed the presence 34 volatile components, the major components were camphene, camphor borneol and caryophyllene. 5 fraction have a good aroma character among 11 fraction were seperated by using silicagel column chromatography. This can is used for the pharmaceutical industry because of amedical action.

• Korean Journal of Veterinary Research
• /
• v.40 no.1
• /
• pp.72-80
• /
• 2000

Lipopolysaccharides (LPS) of Pasteurella multocida (P multocida) and several Gram-negative bacterial pathogens were analyzed by methanolysis, trifluoroacetylation and gas chromatography (GC) on a fused-silica capillary column. The GC analysis indicated that LPS prepared from a strain of P multocida by phenol-water (PW) or trichloroacetic acid (TCA) extraction were quite different in chemical composition. However, LPS prepared from Salmonella enteritidis by the two extraction methods were very similar. PW-LPS extracts from different Pasteurella strains of a serotype had essentially identical GC patterns. Endotoxic LPS extracted from 16 different serotypes of P multocida by PW or by phenol-chloroform-petroleum ether procedures yielded chromatograms indicating similar composition of the fatty acid moieties but minor differences in carbohydrate content. When the chemical composition of endotoxic LPS extracted from several Gram-negative bacteria (P multocida, Pasteurella hacmolytica, Haemophilus somnus, Actinobacillus ligniersii, Brucella abortus, Treponema hyodysenteriae, Escherichia coli, Bacteriodes fragilis, Salmonella abortus equi and Salmonella enteritidis) were examined, each bacteria showed a unique GC pattern. The carbohydrate constituents in LPS of various Gram-negative bacteria were quite variable not only in the O-specific polysaccharides but also in the core polysaccharides. The LPS of closely related bacteria shared more fatty acid constituents with each other than with unrelated bacteria.

• The Korean Journal of Food And Nutrition
• /
• v.17 no.3
• /
• pp.313-321
• /
• 2004

Separation-concentration of sulfur containing heterocyclic compounds(SCHC) from many reaction meat flavors manufactured with Maillard reaction was carried out. Profile of SCHC was identified and analyzed by GC and GC-MSD. The results were as follows. 1. Profile of SCHC could be identified 7 kinds thiazole and 11 kinds thiophene, the major produced compounds were thiophene, thiazolidine, 4-methyl-5-thiazole ethanol. 2. In the case of SCHC, relationship between changes of reaction conditions and the kind of produced components were as same, but produced amounts appeared the difference. Producing amount of complexed SCHC and caramellike note as well as oxygen containing heterocyclic compounds were high level more than high reaction temperature and long time reaction period. 3. Producing ratio of comparative simple structural SCHC were the highest level at reaction conditions of moisture content 50%, reaction temperature 100$^{\circ}C$ and reaction time 2 hours. Reaction conditions for the revelation of reaction meat flavor were below 110$^{\circ}C$ and less than 2 hours. 4. Relationship between moisture content and reaction temperature as well as reaction time had very relative relation. From the change of moisture content and reaction conditions could be obtained the simultaneously profile. Signal presentation for production of reaction meat flavor could be from extraction-separation-concentration of SCHC through simplification of raw-materials in the flavor and seasoning food industry.