• Analytical Science and Technology
• /
• v.27 no.1
• /
• pp.66-77
• /
• 2014

This study was carried out to examine the authenticity discrimination of circulated vegetable oils by using carbon isotope ratio (${\delta}^{13}C$) and fatty acid composition. This analysis was applied to vegetable oils which we can buy in Korean markets, and the analytical instrument was measured by using EA-IR/MS for ${\delta}^{13}C$ and GC/FID for fatty acid composition. ${\delta}^{13}C$ was separated into 3 groups as $C_3$ plant including sesame oil, $C_4$ plant including maize oil, and rice bran oil. Fatty acid composition was significantly different among vegetable oils. In addition, the interval of low and high price vegetable oils was classified through the scatter plot analysis showing the correlation of the ${\delta}^{13}C$ and fatty acid composition. Therefore, through a simultaneous determination of the ${\delta}^{13}C$ and fatty acid composition, we are able to determine the majority of vegetable oils. It help to ensure food safety in Korean market by exclusion of economically modified adulteration in food.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.2
• /
• pp.234-241
• /
• 2015

This study investigated the effects of different cooking methods on contents of cholesterol, retinol, and tocopherol in poultry meats (chicken, Korean native chicken, and duck) using saponification extraction and HPLC analysis. The cooking methods were boiling, grilling, stir-frying, deep-frying, steaming, roasting, and microwaving. Generally, contents of cholesterol increased after cooking. Especially, after deep-frying, large amounts of cholesterol were detected from legs of chicken (94.25 mg/100 g) and wings of Korean native chicken (132.96 mg/100 g). High cholesterol content was detected in wings (233.77 mg/100 g) from duck after microwaving. However, contents of retinol decreased after cooking. The retinol contents of breast meat from Korean native chicken were low ($0.86{\sim}0.56{\mu}g/100g$) compared to other meats ($1.10{\sim}22.66{\mu}g/100g$ in chicken and $1.96{\sim}36.80{\mu}g/100g$ in duck), whereas raw materials from wings of all poultry showed the highest tocopherol contents. Of the various cooking methods, stir-frying and deep-frying resulted in increased ${\alpha}$-tocopherol contents in meats.

• Journal of Nutrition and Health
• /
• v.41 no.5
• /
• pp.428-438
• /
• 2008

Choline is important for normal membrane function, acetylcholine synthesis and methyl group metabolism. In this study, 185 food items customarily eaten by Koreans were selected from the data of the 2001 Korean National Health and Nutrition Survey and analyzed on the total choline content of the foods using enzymatic method of choline oxidase. Foods with high choline concentration (mg/100 g) were listed in sequence of quail egg (476.04 mg), dried squid (452.42 mg), beef liver (427.16 mg), pork liver (424.92 mg), tuna canned in oil (414.44 mg), boiled and dried anchovy (381.30 mg), dried Alaskan pollack (378.88 mg), chicken egg (309.88 mg), chicken liver (259.38 mg), soybean (238.62 mg), French bread with garlic (193.18 mg) and barley (183.73 mg). From this result, it is shown that dried fishes, prepared fishes, livers, eggs, pulses and cereals might be categorized as high choline food. Citron tea and green tea showed low choline content below 1 mg. Vegetables and fruits were also categorized into low choline food. No choline was detected in red pepper powder, beer, soju, soybean oil and corn oil out of foods analyzed in this study. Further study is required for analytic procedure of the foods of which results are inconsistent with USDA's data such as rice and wheat flour.

• KSBB Journal
• /
• v.24 no.1
• /
• pp.41-46
• /
• 2009

Vegetable oils are desirable inexpensive feedstocks for various bioproducts. The content of unsaturated fatty acids such as oleic and linoleic acids are 22% and 55% for soybean oil, 26% and 60% for corn oil, and 61% and 21% for canola oil, respectively. Keto and hydroxy fatty acids are useful industrial chemicals, used in plasticizer, surfactant, lubricant and detergent formulations because of their special chemical properties such as higher viscosity and reactivity compared with other fatty acids. In this study, a microbial isolate, Flavobacterium sp. strain DS5 (NRRL B-14859), was used to convert oleic acid to 10-ketostearic acid (10-KSA) via 10-hydroxystearic acid (10-HSA). Two bioconversion products, 10-KSA and 10-HSA, were quantitatively and qualitatively analyzed using gas chromatography, gas chromatography-mass spectrometry, and $^1H-$ and $^{13}C$-nuclear magnetic resonance. The maximum production of 10-KSA and 10-HSA in flask cultures were 3.4 g/L and 0.5 g/L, respectively. The optimum concentrations of glucose and yeast extract, addition time and volume of oleic acid for 10-KSA production were less than 20 g/L, more than 5 g/L, 18 hand 0.3 ml/50 ml, respectively.

• The Korean Journal of Community Living Science
• /
• v.15 no.1
• /
• pp.91-104
• /
• 2004

This study was designed to investigate and evaluate the dietary intake of 30 housewives, aged 35 to 59. The subjects kept daily diet records lot a period of one year. Their mean daily nutrient intakes met or exceeded the RDA (recommended dietary allowance) for all categories except energy, calcium, iron, vitamin A, and vitamin B$_2$. Mean daily calorie intakes were 81.2% of the RDA. The subjects received about 19% of their energy from fat and 15% from protein. Nutrient adequacy ratios (NAR) were 0.60 for calcium, 0.62 for iron, 0.71 for vitamin A, and 0.76 for vitamin B$_2$. The mean adequacy ratio (MAR) was 0.79. Subjects received various nutrients from rice, pork, eggs, and Kimchi. Rice was a major contribute. to many subjects' nutrient intake due to the high amount of consumption. Pork, rice, and vegetable oil greatly contributed to fat intakes while eggs, pork, and beef supplied a high level of cholesterol compared to other foods. Kimchi, anchovies, and milk were the major contributors of calcium, while rice, pork, and Kimchi were the major contributors of iron. These results indicate that the major nutritional problem of middle-aged housewives is an overall inadequate intake of energy, calcium, and iron.

• Korean Journal of Environmental Agriculture
• /
• v.33 no.3
• /
• pp.198-204
• /
• 2014

BACKGROUND: Caused by cultural environment, the fruit skin stain results in serious damages to pear fruit. Particularly susceptible to this damage, 'Niitaka' pear accounts for 82% of pear cultivation in Korea and many farmers growing the pear trees have suffered economic losses due to fruit skin stain. This study investigated the effect of different treatments of 'Niitaka' pear during growing period on the occurrence of fruit skin stain. METHODS AND RESULTS: The treatments in the field included gibberellin (GA) paste, spraying with amino acid tree fertilizer, functional bagging, and coating of the inner paper bag with agents. The relationships between tree vigor, mineral nutrition concentration and fruit skin stain occurrence were also investigated. The fruit skin stain symptoms occurred from young fruit (May 25) until harvest. There was no exposed fruit flesh. The occurrence of fruit skin stain was significantly reduced in normal tree (shoot length 110 cm), as well as using GA paste treatment, and bagging in calcium and lime sulfur coated bags. However, spraying with amino acid tree fertilizer made no difference in comparison to control. In addition, bags in which the inner paper was coated with lime sulfur and soybean oil resulted in chemical injury to the fruit skin caused by bagging. The K concentration of shoot wood and fruit skin were higher than those of the control. Also, there were lower T-N, K concentration of leaf. CONCLUSION: These results suggest that occurrence of fruit skin stain in 'Niitaka' pear fruits during the growing period can be reduced by GA paste and bagging in calcium and lime sulfur coated bags. The symptoms of chemical injury to the fruit skin caused by bagging in lime sulfur and soybean oil coated inner paper were different compared to skin stain occurring in fruit during the growing period.

• Korean Journal of Food Science and Technology
• /
• v.31 no.3
• /
• pp.855-863
• /
• 1999

To develop new natural antioxidants, antioxidative activity of ethanol (75%) extracts from 50 edible or medicinal plants were examined on lard and palm oil by Rancimat method ($120^{\circ}C$, 20 L/hr). The extracts from Rhus verviciflua STOKES showed comparatively strong antioxidative activity on test. Of the solvents used for extraction, chloroform extract exhibited the strongest antioxidant activity. AI (antioxidant index: induction period of oil containing extract/induction period of control oil) of chloroform extract was higher than that of commercial antioxidant, such as BHT, BHA and ${\delta}-tocopherol$. Free phenolic acid fraction (200 ppm) of the chloroform extract from 75% EtOH extract of Rhus verniciflua STOKES (RCF) showed stronger activity than that of BHT, BHA, and ${\delta}-tocopherol$ at the same concentration. RCF-11 and RCF-13 fractions separated by silicagel column chromatography from the RCF showed stronger activity than other fractions by the Rancimat method.

• Korean Journal of Food Science and Technology
• /
• v.17 no.2
• /
• pp.114-120
• /
• 1985

This study was carried out to investigate the storage stability of Yackwa (a Korean fried cake made from wheat flour, honey and 20% oil), with the variation in frying oils (soybean oil of fresh or heat-treated corn oil and rapeseed oil) and storage conditions (temperature, humidity and in dark or under fluorescent light) for 20 weeks period. In $5^{\circ}C$ storage, acid and peroxide values increased slowly, showing the peroxide value of 20 meq/kg after 13 weeks. In $40^{\circ}C$ storage, acid and peroxide values increased remarkably. The product became harder at storage humidity of 25% and softer by moistening at storage humidity of 80%. Acid and peroxide values of Yackwa from corn, rapeseed and soybean oils increased with storage period, to a different extent. The values of fluorescent groups, especially rapeseed oil group, were higher than those of control groups and the heat-treated oil groups were higher than those of fresh oil groups. Sensory scores for rancid flavor were gradually increased with the storage period in all groups. There was no significant difference with the kinds of frying oils, storage conditions and heat treatment. Correlation of sensory scores with acid values was positive throughout whole storage period, with low ${\gamma}-values$. Its correlation with peroxide values was positive up to 6th week but negative at 9th week of storage.

• Journal of the Korean Wood Science and Technology
• /
• v.38 no.6
• /
• pp.541-546
• /
• 2010

This study was to investigate the dry bond strengths of the plywoods manufactured with 3 hours ozonized soybean oil (SBO)/polymeric methylene diphenyl diisocyanate (pMDI) adhesive at mid and high curing temperature. In results of the dry bonding strengths of the 3 hrs-ozonized SBO mixed with pMDI at high curing temperature were respectively the strengths of weight ratio of 3hrs-ozonized SBO : pMDI, 1 : 0.5, 4.74 kgf/$cm^2$, 1 : 0.75, 7.14 kgf/$cm^2$ 1 : 1, 9.29 kgf/$cm^2$, 1 : 2, 16.53 kgf/$cm^2$, 1 : 3, 17.42 kgf/$cm^2$, and 1 : 4, 16.75 kgf/$cm^2$. Therefore, it was found that the equivalent ratio was formed approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. The dry bonding strengths of the 3hrs-ozonized SBO mixed with pMDI at medium curing temperature were respectively the strengths of weight ratio of 3 hrs-ozonized SBO : pMDI, 1 : 0.5, 3.16 kgf/$cm^2$, 1 : 0.75, 6.13 kgf/$cm^2$ 1 : 1, 8.18 kgf/$cm^2$, 1 : 2, 11.82 kgf/$cm^2$. In this experiment the higher bonding strength at high curing temperature was shown approximately between 3 hrs-ozonized SBO : pMDI 1 : 2 and 1 : 3. If this wood adhesive is used at high curing temperature, it is possibile to bond the plywoods.

• Journal of Environmental Science International
• /
• v.11 no.10
• /
• pp.1109-1116
• /
• 2002

This study analyzed concentrations of volatile organic compounds (VOCs) produced from incineration of papers at $600^{\circ}C$. The papers used in this study included A4 papers (new, printed with ink-jet, printed with carbon), newspapers (printed with bean oil, printed with a general newspaper ink), packaging box, document envelope, single-use paper cup, and cosmetic tissue. Papers were heated from room temperature upto $600^{\circ}C$ providing air inside of the electric furnace and then they were oxidized for 80 minutes at $600^{\circ}C$ maintaining the same air supply. VOCs emitted from the incineration process were sampled using an air sampling pump and bags for 160 minutes and then the components and concentrations of the VOCs were analyzed by a CC-MS. The most prominent chemical structure of the Vous identified from incineration of the papers was furans and then furans were followed by aromatics and aliphatic alkenes. About 40% of the identified VOCs contained double bonds, which have relatively a high ozone (ground level) formation potential, within their molecular structure. Also, some cancer suspecting compounds like benzene, dichlorormethane and chloroform were identified.