• 한국식품과학회지
• /
• 제46권2호
• /
• pp.127-134
• /
• 2014

참치유 보강 에멀젼에 첨가된 참기름은 클로로필의 존재 하에 $25^{\circ}C$, 1,700 lux의 빛에서 에멀젼 유지의 광산화를 유의하게 감소시켰다. 또한 참기름의 첨가는 에멀젼의 광산화 중 산성 조건에서 클로로필로부터 전환된 페오피틴의 분해속도를 낮추어 일중항산소 생성이 많았을 가능성에도 불구하고 일중항산소와 라디칼 소거능을 가진 인지방질, 토코페롤, 폴리페놀 화합물을 제공함으로써 참치유 보강 에멀젼 유지의 산화안정성을 개선하였으며 인지방질, 토코페롤에 비해 폴리페놀 화합물이 더 큰 영향을 주었다. 리그난 화합물은 에멀젼의 광산화 중 변화를 보이지 않아 물리적 기전에 의한 일중항산소 소거 작용을 암시하였다.

• 동아시아식생활학회지
• /
• 제23권4호
• /
• pp.470-476
• /
• 2013

The property of deep frying oil is one of the important factors in fried food quality. The purpose of this study is to identify the quality of deep frying oil in continuous usages for 4 days by two types of fryers: traditional deep-fat fryer and modified oil-water fryer. After frying pork cutlets, the frying oil was kept not only for several physical analyses such as color, viscosity, and water content but also for the quality analyses of frying oil, such as free fatty acid, double bond changes and oxidative rancidity formation. The oil fried in a traditional deep-fat fryer was significantly increased in terms of physical values including moisture content, viscosity, and color, compared to those of the modified fryer, continuously for 4 days. The oil fried by a traditional deep-fat fryer exhibited a significant increase in its free fatty acid content compared to that fried by a modified oil-water fryer, while the iodine value was significantly decreased in the oil fried by a traditional deep-fat fryer when compared to control oil and oil fried by the modified oil-water fryer. In the peroxide value as an indicator of primary oxidation products, the oil fried by both fryers was significantly increased till the second day but decreased in value after the third day because of unstable hydroperoxide decomposition. The p-anicidine value is used as an indicator of secondary oxidation products, the oil fried in a traditional deep-fat fryer was significantly increased in value compared to that of a modified oil-water fryer.

• 한국식품과학회지
• /
• 제49권6호
• /
• pp.584-590
• /
• 2017

수입 팜기름과 수입 후 탈산한 카놀라기름은 $110^{\circ}C$에서 80분 동안 산성백토(1%)를 이용한 탈색과 $250^{\circ}C$, 3 torr에서 3시간 동안의 탈취공정을 거치면서 토코페롤 함량이 감소하였음에도 불구하고 산값과 과산화물값의 감소와 함께 산화 관련 특성은 개선되었으며, 탈취보다는 탈색공정에 의한 개선 효과가 높았다. 탈취공정은 기름의 비정상 향미화합물을 대부분 제거하였으며, 고온에서의 탈색과 탈취공정에도 불구하고 위해 화합물인 벤조피렌 함량에 유의한 증가를 보이지 않았다. 따라서 본 결과는 국내 정제 공정에서 수입 팜기름과 카놀라기름의 품질 개선에 탈취보다는 탈색이 큰 영향을 나타냄을 제시하였다.

• 한국축산식품학회지
• /
• 제36권1호
• /
• pp.23-28
• /
• 2016

This study investigates the effect of cooking, storage, and reheating conditions on the formation of cholesterol oxidation products (COPs) in pork loin. Samples of pork loin procured 24 h postmortem were initially processed and assessed for total fat and cholesterol content. The cooking methods evaluated were pan roasting, steaming, oven grilling, and microwaving. Cooked pork loin samples were stored at 4℃ and reheated after 3 and 6 d of storage using the original method of preparation or alternately, microwaving. Fat content increased significantly with cooking as a result of the loss in moisture but cholesterol content remained unchanged. Pan roasting and microwave cooking caused a significantly higher production of COPs, as with the process of reheating using microwave, pan roasting, and oven grilling methods. The major COPs found in pork loin were cholestanetriol, 20-hydroxycholesterol, and 25-hydroxycholesterol, whose concentrations varied according to the different cooking and reheating methods used. Moreover, the aerobic storage of cooked pork loin under a refrigerated condition also increased the formation of cholesterol oxides on reheating.

• 한국축산식품학회지
• /
• 제39권6호
• /
• pp.918-933
• /
• 2019

Cacao has been shown to have antioxidant effects and health benefits. However, the applicability of cacao as a meat preservative has not been thoroughly evaluated. Here, we examined the effects of cacao nib extracts (CEs) on suppression of fat oxidation and enhancement of quality characteristics of pork patties. Cacao nib powder was extracted in distilled water or 50%, 70%, or 99% ethanol. CEs prepared using 70% ethanol had the highest total phenolic and total flavonoid contents, and the highest 1,1-diphenyl-2-picrylhytdrazyl radical and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities. Decompression-concentrated CEs prepared using 70% ethanol and 0.1% ascorbic acid were added to pork patties, and the physiochemical properties of the patties were measured. The pH of all pork patties increased during storage, but tended to decrease according to the CEs content. CEs enhanced the preservation of redness and texture of the pork patties during storage. Analysis of thiobarbituric acid reactive substances (TBARS) in patties revealed that fat oxidation was highly suppressed in all treatment groups containing CEs during storage, and TBARS values decreased according to CE content. Treatment with 0.1% CE reduced fat oxidation to a level similar to that of treatment with 0.1% ascorbic acid. Consumer flavor preference increased according to CE content, and overall preference was the highest for patties prepared with 0.05% and 0.075% CEs. Overall, 70% ethanol was found to be the optimal concentration for extraction of cacao nibs, and adding 0.05% or 0.075% CEs to pork patties yielded the highest quality.

• Carbon letters
• /
• 제5권4호
• /
• pp.164-169
• /
• 2004

Carbon-ceramic composites refer to a special class of carbon based materials which cover the main drawbacks of carbon, particularly its proneness to air oxidation, while essentially retaining its outstanding properties. In the present paper, the authors report the results of a systematic study made towards the development of C-SiC-$B_4C$ composites, which involves the effects of compositional parameters, namely, carbon-to-ceramic and ceramic-to-ceramic ratios, on the oxidation behaviour as well as other characteristics of these composites. The C-SiC-$B_4C$ composites, heat-treated to $1400^{\circ}C$, have shown that their oxidation behaviour at temperatures of 800~$1200^{\circ}C$ depends jointly on the total ceramic content and the SiC : $B_4C$ ratio. Good compositions of C-SiC-$B_4C$ composites exhibiting zero weight loss in air at temperatures of 800~$1200^{\circ}C$ for periods of 4~9 h, have been identified. Composites with these compositions undergo a weight gain or a maximum weight loss of less than 3% during the establishment of a protective layer at the surface of carbon in a period of 1~6 h. Significant improvement in the strength of C-SiC-$B_4C$ composites has been observed which increases with an increase in the total ceramic content and also with an increase in the SiC : $B_4C$ ratio.

• 한국진공학회지
• /
• 제9권4호
• /
• pp.346-352
• /
• 2000

15%와 42%의 Ge함량을 갖는 poly $Si_{1-x}Ge_x$ 박막을 $700^{\circ}C$의 습식 산화 분위기에서 산화 공정을 진행하고, 박막의 산화 거동을 RBS, XPS, cross-sectional TEM으로 분석하였다. Poly $Si_{0.8}Ge_{0.15}$박막의 경우, $GeO_2$에 비해 열적으로 안정한 $SiO_2$가 우선 생성되고, 반응에 참여하지 못한 Ge은 산화막과 poly $Si_{1-x}Ge_{x}$박막의 계면에 축적되어 산화막 하부의 Ge농도가 증가함을 확인하였다. Poly $Si_{0.8}Ge_{0.42}$ 박막의 경우, 산화막내에 많은 양의 Ge이 $GeO_2$와 Ge 형태로 존재하였고, 이러한 $GeO_2$의 형성으로 인해 산화속도의 증가를 확인하였다. 이러한 분석 결과를 바탕으로 Ge 함량 증가에 따른 poly $Si_{1-x}Ge_x$ 박막의 산화 모델을 제시하였다.

• 대한금속재료학회지
• /
• 제48권1호
• /
• pp.49-56
• /
• 2010

This study investigated how the surface of Al-12wt.%Si alloy modified by the plasma electrolytic oxidation process (PEO). The PEO process was performed in an electrolyte with sodium hexametaphsphate as a conducting salt, and the effect of ammonium metavanadate on variations in the morphology of electrochemically generated oxide layers on the alloy surface was investigated. It is difficult to form a uniform passive oxide layer on Al alloys with a high Si content due to the differences in the oxidation behavior of the silicon-rich phase and the aluminum-rich phase. The oxide layer covered the entire surface of the Al-12WT.%Si alloy uniformly when ammonium metavanadate was added to the electrolyte. The oxide layer was confirmed as a mixture of $V_2O_3$ and $V_2O_5$ by XPS analysis. In addition, the oxide layer obtained by the PEO process with ammonium metavanadate exhibited a black color. Application of this surface modification method is expected to solve the problem of the lack of uniformity in the coloring of oxide layeres caused by different oxidation behaviors during a surface treatment.

• Asian-Australasian Journal of Animal Sciences
• /
• 제10권4호
• /
• pp.402-407
• /
• 1997

This study was conducted to investigate the effects of effects of enprostil, a prostaglandin $E_2$, analogue, on liver triacylglycerol content and factors that regulate liver lipid metabolism in mice. Mice received vehicle or $10{\mu}g$ enprostil/kg body weight intraperitoneally every 6 h, and were killed at 0, 6, 12, 18 and 24 h after the first injection. Enprostil significantly lowered liver triacylglycerol content after 12 h of the first injection. However, the peroxisomal ${\beta}$-oxidation activity was inconsistent with the result of liver triacylglycerol content, because its activity was lovered by enprosil. In another experiment, the effect of enprostil on lipid metabolism in mice was investigated in a short period. Mice received $10{\mu}g$ enprostil/kg body weight intraperitoneally, and were killed after 0, 5, 10, 30 and 60 min. After 30 min, malic enzyme activity was significantly increased by the administration of enprostil compared with the activity at 5 min after. No significant changes in liver carnitine palmitoyltransferase and peroxisomal ${\beta}$-oxidation activities were observed. Plasma free fatty acid concentrations were markedly reduced from 5 through 60 min after the administration of enprostil. Consequently, enprostil suppressive effect on liver triacylglycerol concentration might result from the decreased entry of free fatty acid into liver.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제54권2호
• /
• pp.45-50
• /
• 2005

To improve mean-life and reliability of power cable, in this study, we have investigated electrical properties and stress-strain showing by changing the content of carbon black that is semiconductive additives for underground power transmission. Specimens were made of sheet form with the nine of specimens for measurement. Volume resistivity of specimens was measured by volume resistivity meter after 10 minutes in the pre-heated oven of both 25±1 [℃] and 90±1 [℃]. And stress-strain of specimens was measured by TENSOMETER 2000. A speed of measurement was 200[mm/min], ranges of stress and strain were 400[Kgf/㎠] and 600[%]. In addition tests of stress-strain were progressed by aging specimens in air oven. From this experimental results, volume resistivity was high according to increasing the content of carbon black. And yield stress was increased, while strain was decreased according to increasing the content of carbon black. And stress-strain were decreased some after aging because of oxidation reaction of chemical defect. We could know EEA was excellent more than other specimens from above experimental results.