• Korean journal of food and cookery science
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• v.33 no.3
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• Korean Journal of Materials Research
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• v.19 no.7
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• pp.397-402
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• 2009

In this study, Ti powder was fabricated from Ti scrap by the Hydrogenation-Dehydrogenation (HDH) method. Hydrogenation reactions of Ti scrap occurred at near 450 $^{\circ}C$ with a sudden increase in the reaction temperature and the decreasing pressure of hydrogen gas during the hydrogenation process in the furnace. The dehydrogenation process was also carried out at 750 $^{\circ}C$ for 2hrs in a vacuum of $10^{-4}$ torr. After the HDH process, a deoxidation treatment was carried out with the Ca(purity: 99.5) at 700 $^{\circ}C$ for 2hrs in the vacuum system. It was found that the oxidation content of Ti powder that was deoxidized with Ca showed noticeably lower values, compared to the content obtained by HDH process. In order to fabricate Ti compacts, Ti powder was sintered at $1100\sim1400^{\circ}C$ for 2hrs under a vacuum of $10^{-4}$ torr. The relative density of compact was 94.9% at 1300 $^{\circ}C$. After sintering, all of the Ti compacts showed brittle fracture behavior, which occurred in an elastic range with short plastic yielding up to a peak stress.

• Food Science of Animal Resources
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• v.39 no.5
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• pp.742-755
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• 2019

Cacao bean husk (Theobroma cacao L.) contains a high level of dietary fiber and therefore can be used as raw material in food processing. The objective of the present study was to measure the physicochemical properties and sensory traits of emulsion-type pork sausages with various levels of cacao bean husk powder (0.25%, 0.5%, 0.75%, 1%, and 2%). The moisture content in cooked sausages increased as the level of cacao bean husk power increased, whereas the protein content decreased (p<0.05). With respect to color, as the level of cacao bean husk power increased, there was a decrease in lightness and yellowness, but there was a considerable increase in redness (p<0.05). Cacao bean husk powder exhibited a positive effect on emulsion stability and apparent viscosity. In the sensory evaluation, increased level of cacao bean husk increased flavor acceptability; the 0.75% and 1% treatment groups showed significantly high overall acceptability (p<0.05). The thiobarbituric acid reactive species content of cooked sausages indicated that with the addition of cacao bean husk powder significantly inhibited lipid oxidation in the sausages during refrigerated storage (p<0.05). Overall, the findings of the present study suggest that adding 0.75% and 1% cacao bean husk powder as a natural ingredient in sausages can help develop meat products with excellent qualities.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.15-19
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• 2021

[Purpose] Skeletal muscle glycogen is a determinant of endurance capacity for some athletes. Ginger is well known to possess nutritional effects, such as anti-diabetic effects. We hypothesized that ginger extract (GE) ingestion increases skeletal muscle glycogen by enhancing fat oxidation. Thus, we investigated the effect of GE ingestion on exercise capacity, skeletal muscle glycogen, and certain blood metabolites in exercised rats. [Methods] First, we evaluated the influence of GE ingestion on body weight and elevation of exercise performance in rats fed with different volumes of GE. Next, we measured the skeletal muscle glycogen content and free fatty acid (FFA) levels in GE-fed rats. Finally, we demonstrated that GE ingestion contributes to endurance capacity during intermittent exercise to exhaustion. [Results] We confirmed that GE ingestion increased exercise performance (p<0.05) and elevated the skeletal muscle glycogen content compared to the nonGE-fed (CE, control exercise) group before exercise (Soleus: p<0.01, Plantaris: p<0.01, Gastrocnemius: p<0.05). Blood FFA levels in the GE group were significantly higher than those in the CE group after exercise (p<0.05). Moreover, we demonstrated that exercise capacity was maintained in the CE group during intermittent exercise (p<0.05). [Conclusion] These findings indicate that GE ingestion increases skeletal muscle glycogen content and exercise performance through the upregulation of fat oxidation.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.242-250
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• 2023

Comparative gene identification-58 (CGI-58) is an activating protein of triacylglycerol (TAG) lipase. It has a variety of catalytic activities whereby it may play different roles in diverse organisms. In this study, a homolog of CGI-58 in Phaeodactylum tricornutum (PtCGI-58) was identified. PtCGI-58 was localized in mitochondria by GFP fusion protein analysis, which is different from the reported subcellular localization of CGI-58 in animals and plants. Respectively, PtCGI-58 overexpression resulted in increased neutral lipid content and TAG accumulation by 42-46% and 21-32%. Likewise, it also increased the relative content of eicosapentaenoic acid (EPA), and in particular, the EPA content in TAGs almost doubled. Transcript levels of genes involved in de novo fatty acid synthesis and mitochondrial β-oxidation were significantly upregulated in PtCGI-58 overexpression strains compared with wild-type cells. Our findings suggest that PtCGI-58 may mediate the breakdown of lipids in mitochondria and the recycling of acyl chains derived from mitochondrial β-oxidation into TAG biosynthesis. Moreover, this study potentially illuminates new functions for CGI-58 in lipid homeostasis and provides a strategy to enrich EPA in algal TAGs.

• Journal of the Korean Applied Science and Technology
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• v.29 no.2
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• pp.330-338
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• 2012

During 10 days germination of perilla seeds for sprouts preparation, the changes of proximate composition and antioxidant activities were monitored, and the inhibitory effect of sprouts extracts on perilla oil oxidation was also studied. The moisture content in seeds(2.9%) was increased to 9.2% in sprouts at 10 days while crude ash content wasn't significantly. The crude fat and protein contents were reduced from 46.8% and 20.7% in seeds to 18.2% and 18.3% in sprouts, respectively, but reducing sugar and fiber contents increased from 2.2% and 14.8% to 12.8% and 22.4%, respectively. Compared with perilla leaf, sprouts at 10 days contained more fat, carbohydrate, reducing sugar, and fiber while less moisture, ash, and protein. Antioxidant activities during germination were increased and reached to maximum at 8 days in which Trolox equivalent antioxidant capacity(TEAC) based on DPPH and ABTS radical scavenging were 133.1 and 136.8 Trolox eq. mmol/kg, respectively, and ferric ion reducing power(FRAP) was 399.3 Fe(II) eq. mmol/kg. Polyphenol content(19.2 g/kg) was maximum at this stage, too. Perilla leaf showed similar TEAC but higher FRAP than the sprouts. When methanol extract of sprouts at 8 days was added to perilla oil, the oil oxidation was delayed in dose dependent manner. The induction time for oxidation was extended about 2.8 times by adding 2.5%(w/w) extract, that is, from 1.67 hr(control) to 4.62 hr. This induction time corresponded to 38% level of that of perilla oil containing 2.5% BHT.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.37-43
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• 1973

In this paper, non-enzymatic browning reactions as a factor of self stability of boiled and dried anchovy were studied to discuss the effect of water activity to the discoloring reaction and the preservative moisture content. The development of rancidity of the fish meat was also mentioned since the fish is fatty and the lipid oxidation is a functional deteriorative reaction. Fresh anchovies were boiled in $10\%$ salt solution immediately after the catch, sun dried, and stored at room temperature ($20^{\circ}C$) for two months in humidistat chambers maintaining different levels of water activity as described in Table 1. The pigments formed by non-enzymatic browning reations were extracted in two fractions, those were chloroform-methanol soluble and water dialyzed fraction, and analyzed spectrophotometrically at the wavelength of 460 nm. These two fractions were considered, respectively to be the brown pigments formed by lipid oxidation reactions for the formler and for the latter, to be the pigments developed by sugar-amino or Maillard reaction. The oxidation of lipid in anchovy meat during the storage was measured as the changes in Peroxide value and the color development of thiobarbituric acid reaction. It is summarized from the results that the rate of both reactions, lipid oxidation and browning, was affected by water activity levels. In regard to the changes in peroxide and TBA value during the storage, the propagation of lipid oxidation was obviously accelerated at lower humidities whereas the development of browning progressed at the higher. These two reactions occurring simultaneously and contrary in activity resulted in that the rate of deterioration occurring oxidatively or by browning, was the minimum at the water activity of 0.32-0.45 which were $7-9\%$ as moisture content and slightly higher value than that of monolayer (Aw=0.21, $5.11\%$ as moisture content). It is also noted that the lipid oxidative browning was presumed to dominate sugar-amino reactions so that the rate of browning of the meat was ultimately depended on the development of rancidity although sugar-amino reactions initiated earlier than the other at the first ten days of storage, particulary at higher humidity. At the lower humidity sugar-amino reactions were occurred gradually but lower levels in color development in contrast to the consistent increase in lipid oxidative browning.

• New & Renewable Energy
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• v.19 no.4
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• pp.27-34
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• 2023

In this study, microalgal oil was extracted from Nannochloropsis oceanica cultured in an open raceway pond and converted into biodiesel using a solid acid catalyst. Microalgal oil was extracted from two types of microalgae with and without nitrogen starvation using the KOH-solvent extraction method and the fatty acid content and oil extraction yield from each microalgae were compared. The fatty acid content of N. oceanica was 184.8 mg/g cell under basic conditions, and the oil content increased to 340.1 mg/g under nitrogen starvation conditions. Oil extraction yields were 90.8 and 95.4% in the first extraction, and increased to 97.5 and 98.8% after the second extraction. Microalgal oil extracted by KOH-solvent extraction was yellow in color and had reduced viscosity due to chlorophyll removal. In biodiesel conversion using the catalyst SO₄^2-/HZSM-5, solvent-extracted oil showed a FAME content of 4.8%, while KOH-solvent-extracted oil showed a FAME content of 90.4%. Solid acid catalyst application has been made easier by removal of chlorophyll from microalgal oil. The FAME content increased to 96.6% upon distillation, and the oxidation stability increased to 11.07 h with addition of rapeseed biodiesel and 1,000 ppm butylated hydroxyanisole.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.4
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• pp.13-18
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• 1999

Recently among after-treatment devices which have high possibility of utility diesel oxidation catalyst(DOC) is concerned over the world. DOC oxidizes pollutants by means of activate-reaction during by-passing in the catalyst in doing so conversion efficiency of PM, CO and HC is high and this device does not have an effect on engine performance because back pressure is not nearly increased, But as a small amount of sulfur content in fuel is oxidized it makes sulfate which is absorbed on the surface of catalyst. So in this study the experiment is carried out by means of using ordinary fuel(0.1wt%) and low sulfur fuel(0.05wt%) with DOC and the emission gas of diesel engine is measured.

• Journal of the Korean Ceramic Society
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• v.27 no.1
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• pp.109-117
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• 1990

Magnetite for Water-based ferrofluid was synthesized by air oxidation of aqueous suspension in the pH range 7-12 at $65^{\circ}C$. The optimum condition of magneite formation was delineated by examining various physicochemcial properties such as Fe2+ content, phase characteristics, MHC and $\sigma$max. The point of zero charge of iron oxide powders obtained at various pH conditions were correlated with the oxidation state of Fe in the iron oxide. The magnetite powder prepared at pH 9 ws dispersed using sodium oleate and sodium dodecylbenzenesulfonate (SDBS) as dispersants, and the dispersion characteristics of the magnetite ferrofluid were examined by means of the fraction of solid dispersed, zeta potential data and FT-IR spectrum. A simple calculation on the potential energy of two interacting magnetite particles showed that the dispersion stability was directly correlated with height of the potential energy barrier or the shape of zeta potential.