• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1562-1568
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• 2011

We studied the amounts of trans fatty acids and saturated fatty acids in child-favored foods. Confectioneries, breads, donuts and hamburgers were included in this study. The total fatty acid content and the amount of each type of fatty acid were determined by gas chromatography with a flame-ionized detector. Confectioneries were shown to have the highest content of crude fat. The mean content was 24.2${\pm}$6.9 (range: 4.6~41.1) g/100 g food. The mean content of crude fat in donuts, bread and hamburgers was 23.9${\pm}$5.8 (range: 14.1~39.5) g/100 g food, 15.7${\pm}$7.9 (range: 1.4~30.0) g/100 g food, and 9.5${\pm}$3.4 (range: 4.5~18.5) g/100 g food, respectively. Bread had the most trans fatty acids at 1.3 g/100 g food. This result inferred that manufacturers have tried to reduce the trans fat content. The mean content of saturated fatty acids in confectioneries, donuts, bread, and hamburgers was 11.6${\pm}$4.8 (range: 2.0~22.7) g/100 g food, 11.2${\pm}$4.0 (range: 4.8~23.2) g/100 g food, 6.9${\pm}$4.1 (range: 0.6~15.4) g/100 g food, 3.0${\pm}$1.0 (range: 1.0~5.8) g/100 g food, respectively. This content depended on crude fat. The composition of fatty acids varied according to the oil and fat used in the manufacturing process of each food, and the natural content. Foods that were fried in vegetable oil tended to be especially low in saturated fat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1278-1286
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• 2008

The effect of Tween 20 addition on changes in the stability of methylcellulose (MC) emulsions (1 wt% MC, 10 wt% n-tetradecane, 20 mM bis-tris buffer, pH 7) was investigated by creaming stability and orthokinetic stability measurements. In the case of MC emulsions containing varying amounts of oil (1$\sim$30 wt%) and no Tween 20 added, creaming stability, judged by mean migration velocity of fat globules ($V_m$), was found to depend on droplet size: the larger the droplet size, the worse the stability [$V_m$: 0.326 $\mu$m $min^{-1}$ ($d_{32}$: 0.32 $\mu$m) ${\rightarrow}V_m$: 0.551 $\mu$m $min^{-1}$ ($d_{32}$: 0.53 $\mu$m)]. With Tween 20, creaming stability was found to be worse than the one without Tween 20, except for MC emulsion containing 0.2 wt% Tween 20. In addition, cream stability was the lowest with the lowest concentration of Tween 20 and a tendency to recover with increasing Tween 20 concentration [$V_m$: 0.598 $\mu$m $min^{-1}$ (0.01 wt%)${\rightarrow}V_m$: 0.389 $\mu$m $min^{-1}$ (0.2 wt%)] was found. From viscosity measurement for aqueous bulk phase of MC emulsions, such a change in the creaming stability was found to coincide well with the results of viscosity measurement. Therefore, it was reasonable to say that creaming stability of MC emulsions containing Tween 20 depended on MC concentration in aqueous bulk phase, which was in turn varied by competitive adsorption between MC and Tween 20 at the oil droplet surface. In case of orthokinetic stability, judged by destabilization time ($t_d$), it was found that the addition of Tween 20 resulted in lowered stability with more pronounce tendency at higher concentrations [$t_d$: 160 min (0.03 wt%)${\rightarrow}t_d$: 100 min (0.2 wt%)]. Moreover, combined with previous results, the orthokinetic stability of MC emulsions containing Tween 20 was found to be exponentially proportional to MC load. In conclusion, competitive adsorption between MC and Tween 20 may affect the stability properties of MC emulsion to varying extents, depending on the concentration of Tween 20.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1753-1759
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• 2009

The present study was conducted to investigate the effects of components obtained from Zanthoxylum schinifolium and Zanthoxylum piperitum on rancidity and quality of Kwamegi (semi-dried Pacific saury, Coloabis saira). Ethanol extract (ZS) of Zanthoxylum schinifolium leaves or the essential oil (ZP) obtained from pericarp of Zanthoxylum piperitum in 1 or 20% ethanol solution was sprayed to the Pacific saury before Kwamegi preparation at its final concentrations of 0.125~2 ppm in the Kwamegi. The prepared Kwamegi was vacuum packed with multi-layered film (polyethylene/polyamide/EVOH/polyethylene, thickness 80 μm) and kept at -20${^{\circ}C}$ until use. After opening the package Kwamegi was stored at 4${^{\circ}C}$ for 1, 3 and 7 days during which rancidity tests and sensory evaluation were carried out. Acid, peroxide, and thiobarbituric acid (TBA) values increased with storage time but reduced significantly by the addition of ZS at the concentrations of ≥G0.125 ppm and ZP≥F0.25 ppm. The effects of ZS and ZP were dose-dependent and more pronounced as storage time prolonged. The ZS and ZP also reduced dimethyamine and trimethyamine (TMA) contents which were increased with time, while they prevented the decrease of trimethyamine oxide. The ZS at the concentration of ≥G0.25 ppm and the ZP at >0.5 ppm were needed to maintain TMA less than 4.5 mg/100 g for 3 day storage at 4${^{\circ}C}$. Sensory evaluation of the Kwamegi exhibited a slightly higher preference with the ZS and ZP treated ones at the level of 0.25~0.5 ppm. It is concluded that very low amounts of ZS and ZP are effective in suppression of rancidity of Kwamegi and could be utilized for its quality management.

• Journal of Nutrition and Health
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• v.52 no.1
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• pp.47-57
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• 2019

Purpose: This study was conducted to investigate the relationship between atopic dermatitis and dietary fat and fatty acid (FA) intakes in 9 ~ 11 year old children. Methods: We analyzed data from the combined 2013 ~ 2015 KNHANES (Korean National Health and Nutrition Examination Survey). Subjects were divided into two groups according to atopic dermatitis (AD); with AD and without AD. Data pertaining to macronutrients and FA intakes were obtained by a single 24-h dietary recall. Food sources were identified based on the amounts of total fat and FA consumption according to each food. The associations between each FA intake and atopic dermatitis were analyzed using simple and multiple logistic regression analyses. Age, sex, body mass index (BMI) and income levels were adjusted as covariates. Results: Of the participants, 17.69% suffered from atopic dermatitis. Children with AD had significantly lower fat percentages of total energy and higher carbohydrate percentages of total energy than normal children. Percentages of energy and intakes of polyunsaturated fatty acid (PUFA), n-3 FA and n-6 FA in children with AD were significantly lower than those in normal children. In the FA, linoleic acid, ${\gamma}$-linoleic acid and ${\alpha}$-linolenic acid levels of children with AD were significantly lower than those of normal children. However, the P/S ratio and n-6/n-3 ratio did not differ significantly between children with AD and normal children. Soybean oil was the main contributor to PUFA, n-3 FA and n-6 FA in both groups, while perilla seed oil and mackerel were the major food sources of n-3 FA in children with atopic dermatitis. Atopic dermatitis was significantly correlated with low-fat and high-carbohydrate diets. The adjusted odds ratios were 0.966, 0.776 and 0.963 for PUFA, n-3 FA, and n-6 FA intakes, respectively. Conclusion: The present study provides reliable evidence regarding the relationship between fat and FA intakes and AD in Korean children 9 ~ 11 years of age.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.565-572
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• 2020

The 3-monochloropropane-1,2-diol (3-MCPD) is a contaminant that occurs in foodstuffs in its free form as well as in its bound form. The objective of this study was to evaluate the effects of emulsifier, frying temperature, and the amounts of salt and oil on the formation of bound 3-MCPD in a fried snack model. Emulsifier affected the formation of bound 3-MCPD; furthermore, it was observed that the largest amount of bound 3-MCPD was detected in the fried snack model when glycerin esters of fatty acids were used as emulsifiers. Frying temperature also affected the formation of bound 3-MCPD, which increased significantly as the frying temperature increased from 145 to 190℃. In addition, salt affected the formation of bound 3-MCPD. As the amount of salt increased, the amount of bound 3-MCPD also increased significantly. Moreover, it was observed that the amount of oil did not affect the formation of bound 3-MCPD. These results will aid in the reduction of bound 3-MCPD in fried snacks.

• Food Science and Preservation
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• v.30 no.1
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• pp.155-169
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• 2023

Jerusalem artichoke (JA, Helianthus tuberosus L.) has a great potential to enhance the quality of yakju due to the plentiful inulin content which is functional and indigestible carbohydrate in human. In this study, the optimal preparation conditions such as the added amount and steam treatment of JA were investigated to improve the quality of yakju. As the amount of JA added to yakju increased, alcohol production decreased, whereas fermentation was performed well when the steam-cooked JA was added to yakju. The pH and total acidity of yakju decreased and increased, respectively, when the amount of JA added to yakju increased, whereas pH and total acidity of yakju increased and decreased, respectively, when the steam-cooked JA was added to yakju. The free sugar and organic acid contents of yakju increased and decreased, respectively, when the amount of JA added to yakju increased, whereas those of yakju decreased when the steam-cooked JA was added to Yakju. Amino acid content of JA decreased as the amount of JA added to yakju increased and that of JA significantly decreased when the steam-cooked JA was added to yakju. In the sensory evaluation analysis, the addition of 10% unsteam-cooked JA to yakju was the best when considering sweetness, flavor, sourness, and overall preference of yakju supplemented with JA. Consequently, utilizing JA to yakju may contribute to the improvement of the quality of yakju.

• The Journal of the Petrological Society of Korea
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• v.19 no.2
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• pp.141-156
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• 2010

Dokdo Island, Korea, is located in the East Sea belonging to back arc basin. In this study we examined petrology and geochemistry of massive tuffaceous breccia (MTB) from Dongdo (Eastern islet) and Seodo(Western islet), the two largest islands of Dokdo. Field studies and chemical analysis distinguish the MTB in Dongdo and Seodo. The Dongdo MTB (DMTB) is exposed up to 50 m on the ocean cliff and it has dominant basalt and trachybasalt with moderate amount of trachyte and scoria. On the other hand, Seodo MTB (SMTB), which is preserved between trachyte dike and trachyandesite, is composed of roughly equal amounts of basalt, trachybasalt and trachyte. The location of the islets were related to the source vent having in contact with underlying trachyte lava and differential pyroclastic deposits made them different characteristics. According to trace element analysis of trachytic volcanic clasts, the Ba concentration ranges from 66 to 103 ppm and Sr varies from 44 to 56 ppm in DMTB. However, Br and Sr in SMTB correspondingly showed relatively wide ranges: Br 785-1259 ppm and Sr 466-1230 ppm. These differential trends between DMTB and SMTB, along with the difference in P and Ti, indicate that the crystallization of alkali feldspar, feldspathoid, biotite, apatite and titanium took place differently. Nevertheless, DMTB and SMTB are similar in REE patterns and they are correspondingly characterized by high LREE, low HREE and similar $(La/Yb)_N$ values with 23.9-40.2 in DMTB and 27.4-32.9 in SMTB. These patterns suggest that Dongdo and Seodo might be originated from coeval magma suites. Dokdo island shows high concentrations of Ba, K and Rb. These signatures mark a result attributed to the mantle upwelling because the magma derived from the asthenosphere was metasomatized with subduction-related fluids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1575-1581
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• 2011

Rapeseed cake, which is the organic waste remaining after rapeseed oil production, is readily available and considered an ecologically-friendly resource with very low cost and high dietary fiber content. This research was carried out for two reasons. First, it was done to analyze the liberated reducing sugar content of rapeseed cake. Second, it was done to investigate the effects on the sugar yield of the various concentrations of acidic and alkaline catalysts used for the hydrolysis of rapeseed cake and the concentrations of rapeseed cake in each catalyst. Several amounts of ground rapeseed cake, 0.5 g, 1 g, and 2 g, were put into 100 mL of catalysts such as sulfuric acid (0.5~2%), hydrochloric acid (0.5~2%), and sodium hydroxide (0.5~2%). Then they were hydrolyzed for 5 min at 121$^{\circ}C$. After hydrolysis, HPLC equipped with an RI detector was used to analyze liberated reducing sugars such as sucrose, glucose, galactose, fructose, and arabinose separated from rapeseed cake. The degradation rate of rapeseed cake was the highest in hydrochloric acid. As the catalyst concentrations used for hydrolysis of rapeseed cake increased, the degradation rate of rapeseed cake also significantly increased. Total reducing sugar content was the highest in hydrochloric acid, and it increased with the increase of catalyst concentrations. However, as the amount of rapeseed cake increased, the total reducing sugar content decreased, exceptionally sucrose in the case of sodium hydroxide.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.99-106
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• 2006

Chlorothalonil and imidacloprid sprayed onto the green peppers were degraded more faster at outdoor than in greenhouse. These results were affected by dew and photodegration, considering no rain during the experimental period. Chlorothalonil, esfenvalerate and imidacloprid in green pepper, green twist pepper and sweet pepper did not show any residual pattern, because green peppers are one of the continuous harvesting crops and pesticides could not be sprayed homogeneously on them. When green peppers were pickled with soy sauce and green twist peppers were fried with vegetable oil, the amounts of pesticides such as alpha-cypermethrin, bifenthrin, chlorfenapyr, esfenvalerate and imidacloprid were diminished to the levels of about $30{\sim}71$ and $20{\sim}41%$, respectively. Esfenvalerate and imidacloprid could not be detected in 2 month-old hot pepper paste. The removal rates of pesticide residues in leaves of green peppers were about $22{\sim}37%$ by washing, about $74{\sim}95%$ by parboiling, and about $17{\sim}55%$ by drying after parboiling.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.48-59
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• 2018

This study was conducted to suggest the effective management and recycling processes of coffee waste, which can be easily obtained from coffee shops and coffee-related products industries. Prior to the fabrication of pellets, the potential of coffee waste as a raw material of pellet was investigated through the examination of its chemical compositions and fuel characteristics. Major gradient included in coffee waste was holocellulose, followed by fat/oil and protein. Coffee waste contained a small quantity of ash (0.7%), such as calcium, sodium, potassium and magnesium. Interestingly, coffee waste was easily dried probably due to its porous structure. Pellets fabricated with coffee waste and larch sawdust showed good fuel characteristics, such as moisture content, ash content, density and durability. The pellets exceed greatly the minimum requirements of $1^{st}$-grade wood pellet standard designated by National Institute of Forest Science (NIFOS). Particularly, the high calorific value of coffee waste showed the potential as a raw material of pellet. However, owing to high nitrogen and sulfur contents, coffee waste is like to be used as a raw material of wood pellet for combined heat and power plants equipped with a reduction system of $NO_x$ and $SO_x$ gases. On the other hand, 91 wt% larch sawdust and 9 wt% coffee waste are required to fabricate the $1^{st}$-grade wood pellets designated by NIFOS. Pellets fabricated with the conditions are estimated to have nitrogen content of 0.298% and sulfur content of 0.03%. Lastly, if amounts of coffee waste and sawdust in the production of wood pellets are adequately adjusted according to its purchasing price, the manufacturing cost of pellet can effectively be reduced. In addition, it is expected tp prepare the effective recycling process of waste and to relieve the environmental burden with the reduction of waste from the commercialization of coffee waste/larch pellets.