• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.76-80
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• 1991

To isolate oryzanol from the by-product of rice bran oil refinning, experiment of solvent fractional crystallization was carried out at various conditions with the dark oil obtained by acidifying the soap stock of micella refinning process and the pitch obtained from vacuum distillation of the dark oil. The impurity interfering the crystallization process such as waxes can be removed as precipitates by cooling the 1:1 mixtrue of acetone and dark oil to $0^{\circ}C$, From the dewaxed dark oil, oryzanol concentrate with 51.3% purity was obtained by fractional crystallization at$0^{\circ}C$ with the mixture of 8 part volume of hexane and 1 part of the dewaxed dark oil. The concentrate was recrystallized at room temperature with 20 part volume of methanol to yield oryzanol crystal of 98.3% purity. The optimum condition of vacuum distillation was temperature of $180^{\circ}C\;at\;0.2{\sim}0.4\;torr$ with 2% steam sparging. At this condition, the free fatty acid in the dark oil was removed as distillate without thermal deomposition to yield 82.3% of oryzanol as the pitch of 27.3% purity. After concentration from the pitch with 20 part volume of hexane to yield yellow powder of 75.4% purity, the yellow powder was recrystallized in methanol at room temperature to obtain the crystal containing 99.0% oryzanol. The overall oryzanol yield from the dark oil and the pitch was 9.5 and 28.5%, respectively. The change of the composition of sterols and triterpenoid alcohols in the compounds isolated during fractionation was analyzed by GC-MS.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.105.1-105.1
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• 2010

바이오디젤 보급 활성화에 따른 식물성 원료유의 가격 상승 및 수급 불안정성 문제를 해결하고자 폐유지를 원료로 바이오디젤을 생산하고자 하는 시도가 이루어지고 있다. 폐유지의 사용은 폐자원 활용 측면에서 의미가 있으며 바이오디젤 생산 단가를 낮출 수 있다. 다양한 폐유지가 산업체로부터 배출되며 이 중에서 dark oil은 식용유 공장에서 식물성 원료유의 정제 과정에서 생기는 부산물로 바이오디젤로 전환 가능한 성분을 포함하고 있다. 본 연구에 사용된 dark oil은 54.9%의 유리지방산과 28.0%의 triglyceride, 4.4%의 diglyceride, 그리고 1% 이하의 monoglyceride를 함유하고 있다. Dark oil의 초기 산가는 109.8 mg KOH/g이었다. 본 연구에서는 dark oil의 유지 부분(triglyceride, diglyceride, monoglyceride)을 유리지방산으로 전환시켜 HAAO(high acid acid oil)을 생산한 후, 고체 산 촉매에 의한 에스테르화 반응을 통하여 바이오디젤을 생산하고자 하였다. 유지 부분의 유리지방산 전환 반응을 위하여 음이온성 계면활성제인 SDBS(sodium dodecyl benzene sulfonate)가 사용되었다. Dark oil:황산:물의 질량비가 10:2:10이고 SDBS가 오일 대비 3%인 조건에서 dark oil의 산가는 190.8 mg KOH/g까지 증가하였고, dark oil:황산:물의 질량비가 10:4:10이고 SDBS가 2%인 조건에서는 산가가 194.2 mg KOH/g까지 증가하였다. 생산된 HAAO을 이용하여 오일 대비 30%의 Amberlyst-15 촉매 하에서 HAAO:메탄올 몰비 1:9인 조건에서 에스테르화 반응을 수행하였을 경우 FAME(fatty acid methyl ester) 함량은 81.3%까지 증가하였다. 고체 산 촉매로써 Amberlyst-15와 가격 면에서 저렴한 PC101을 비교하였을 경우 FAME 함량은 각각 80.7%, 77.9%로 비슷한 효율을 나타내었다. 생산된 바이오디젤의 FAME 함량을 높이기 위해 증류 공정을 필요로 하였다.

• Korean Journal of Food Science and Technology
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• v.42 no.1
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• pp.14-20
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• 2010

Naturally present antioxidants, tocopherols, carotenoids, and phospholipids in the bran and germ oils from Keumkang (K-WBG oil) and Dark Northern Spring wheats (DNS-WBG oil) were determined during storage under 1700 lux light at $5^{\circ}C$ by HPLC. Oil oxidation was monitored by peroxide values (POV) and conjugated dienoic acid content. The results showed that antioxidants were degraded during storage of the WBG oils under light, with higher degradation rates for carotenoids and phospholipids in the K-WBG oil compared to the DNS-WBG oil. Light increased oil oxidation and the rate of oxidation was higher in K-WBG oil than in the DNS-WBG oil. There was a high correlation between POV and residual amounts of antioxidants during photo-oxidation, with phospholipids showing the greatest effects on POV. This study suggests that a higher amount and lower degradation rate of phospholipids in the DNS-WBG oil contributed to its higher photo-oxidative stability compared to the K-WBG oil.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.287-292
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• 2012

Light effects on temperature dependence of safflower oil oxidation and tocopherol degradation were studied. Safflower oil was oxidized at 20, 40, 60, or $80^{\circ}C$ for 30, 30, 15, and 6 days, respectively, in the dark or under light. Oil oxidation was evaluated with peroxide value (POV) and conjugated dienoic acid (CDA) value, and tocopherols were monitored by HPLC. Safflower oil consisted of palmitic, stearic, oleic, and linoleic acids at 7.3, 2.0, 14.2, and 76.6%, respectively, with tocopherols at 1157.1 mg/kg. Peroxide and CDA values of safflower oil increased while tocopherol contents decreased with the oxidation time and temperature. Light increased and accelerated the oil oxidation and tocopherol degradation. Temperature dependence of the oil oxidation and tocopherol degradation was higher in the dark rather than under light. The results suggest that temperature control could be more essential in the dark rather than under light with regard to the oxidative stability of safflower oil.

• Journal of Aquaculture
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• v.22 no.1
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• pp.63-67
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• 2009

In order to establish optimum anesthesia concentration, we tested the efficacy of clove oil at five different concentrations in large sized (mean SL $17.1{\pm}2.21\;cm$) and small sized (mean SL $0.6{\pm}0.06\;cm$) dark-banded rockfish Sebastes inermis. Optimal anesthesia concentration for dark-banded rockfish was $150\;mgL^{-1}$ in both large and small sized fish. In general, fish exposed to higher anesthetic doses were rapidly induced but took longer to recover (P<0.05). Recovery time of small sized fish was longer than large sized fish in lower concentrations, while recovery time of large sized fish was longer than small sized fish in higher concentration (P<0.05). Using the established optimum aesthetic concentration, we evaluated the physiological response of dark-banded rockfish to clove oil by measuring plasma cortisol and glucose levels. Following administration of $150\;mgL^{-1}$ clove oil at $20^{\circ}C$ (optimum breeding temperature), plasma cortisol level was highest ($42.2{\pm}11.318{\mu}g/dL$) after 0 hour, while plasma glucose level was highest ($52.5{\pm}10.61\;mg/dL$) after 1 hour. Plasma cortisol and glucose concentrations required 6 and 2 hours, respectively, to return to pre-exposure levels.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.55-58
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• 2005

Sophorolipid was produced by Candida bombicola ATCC 22214 from soybean dark oil, a byproduct of soybean oil processing. With a fed-batch culture of C. bombicola for 7 days, 90 g/l of sophorolipid was obtained. The CMC (critical micelle concentration) and minimum surface tension of the sophorolipid in aqueous solution were found to be 150 mg/l and 48 mN/m, respectively. The dispersion capability of sophorolipid was higher than that of the chemical surfactants such as SDS and Brij30. The molar solubility ratio (MSR) of 4-methylnaphthalene was 0.2. Linoleic and oleic acids were the main constituents of the fatty acid composition of the sophorolipid. The sophorolipid showed antimicrobial activity against Propionibacterium acne and Bacillus subtilis.

• Food Science and Preservation
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• v.11 no.1
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• pp.42-46
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• 2004

Each pigments were obtained by ethyl alcohol extraction method, blue and yellow pigment from Gardenia as well as dark brown pigment from Kaoliang. Concentration of these pigments are all 60 Brix, the extraction yields were 0.68, 1.97, 0.63 ％(w/w), respectively. Oil soluble natural black pigment (OSNBP) was composed of soybean oil, water, emulsifier, Gardenia blue and yellow, Kaoliang dark brown etc. Blending ratio of these was 8: 22: 42: 10: 15: 13 (w/w), this mixture was carried out homogenized. Solubility of this OSNBP in soybean oil was appeared the maximum level at about 30∼40$^{\circ}C$ range. OSNBP solubilized black oil was not reseparated at below 20$^{\circ}C$.

• Korean journal of food and cookery science
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• v.29 no.1
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• pp.53-62
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• 2013

Lipid oxidation and antioxidants changes in perilla oil emulsion added with chlorophyll were studied during storage in the dark or under 1,700 lux light at $25^{\circ}C$ for 48 h. The emulsion was consisted of perilla oil (33.12 g), 5% acetic acid (66.23 g), egg yolk powder (0.5 g), and xanthan gum (0.15 g), and Chlorophyll b was added to the emulsion at 0, 2.5 and 4 mg/kg. The lipid oxidation was evaluated by headspace oxygen consumption and hydroperoxide formation, and tocopherols and polyphenols were monitored by HPLC and spectrophotometry at 725 nm, respectively. The lipid oxidation of the perilla oil emulsion in the dark was not significant regardless of the addition of chlorophyll. Light increased and accelerated the lipid oxidation of the emulsion, and increased addition level of chlorophyll under light increased it further. However, there was no significant change in fatty acid composition in any case. Contents of tocopherols and polyphenols in the emulsion were not significantly changed during storage in the dark regardless of chlorophyll addition, indicating their little degradation. Tocopherols and polyphenols in the emulsion were significantly degraded during storage of the emulsion under light, and the degradation rate of polyphenols was increased with addition level of chlorophyll. The lipid oxidation of the perilla oil emulsion was inversely related with the residual amounts of tocopherols and polyphenols, with more dependent on the retention of polyphenols than that of tocopherols.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.628-635
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• 2009

Autoxidative stability of wheat bran and germ oil extracted from Keumkang wheat (WBG-K) or Dark Northern Spring wheat (WBG-DNS) at $50^{\circ}C$ in the dark was compared by peroxide values (POV) and fatty acid composition by gas chromatography. Changes of minor compounds were monitored by HPLC. WBG-K showed significantly higher linoleic but lower oleic acid content than WBG-DNS. WBG-DNS contained more phospholipids but less tocopherols and carotenoids than WBG-K. POV of oils was increased during storage, with no significant difference in the oxidation rates between two oils. Tocopherols, carotenoids, and phospholipids in both oils were degraded during the autoxidation. Total phospholipids content showed the highest correlation with the degree of oxidation in WBG oils. The results clearly showed that both fatty acid composition and contents of tocopherols, carotenoids, and phospholipids co-affected the autoxidation of WBG oil.

• Korean journal of food and cookery science
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• v.5 no.2
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• pp.27-34
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• 1989

In the present study, the oxidative stability of Korean evening primrose oil (EPO) stored in various conditions, i.e., dark, cool, fluorescent light and daylight irradiation were investigated. Furthermore difference between the compositional content of gamma-linolenic acid (GLA) of EPO and that of alpha-linolenic acid of soybean oil (SOY) undergoing various modes of oxidation was observed. The results of the present study were as follows: More rapid autoxidative reations of EPO than that of SOY in vairous conditions increased in order of daylight, fluorescent light, cool and dark. Espectially, autoxidative rates of EPO increased rapidly on exposure to daylight and fluorescent light. This probably was due to chlorophyll functioned as a photosensitizer resulting in rapid oxidation of the EPO during irrdadiation of light. However, there was no difference between compositional content of GLA in EPO and alpha-linolenic acid in SOY undergoing various modes of oxidation. Therefore, theripid oxidative rate of EPO could be due to the catalytic effect of the chlorophyll on the photoxidation and the free radical reaction of PUFA.