• Korean Journal of Food Science and Technology
• /
• v.34 no.2
• /
• pp.157-163
• /
• 2002

An investigation was carried out to study the characteristics of lipoxygenase in dioctyl sulfosuccinate (aerosol-OT, AOT)/isooctane revered micelles of microaqueous system containing infinitesimal water. ${\alpha}-Linoleic$ acid as a substrate could be analyzed by the colorimetric methodology using 5%(w/v) cupric acetate-pyridine solution and the activity of lipoxygenase was able to be assayed by the degree of ${\alpha}-linoleic$ acid consumption per minute. Optimal pH, temperature, and R-value ([water]/[AOT]) were determined as the value of 5.0, $25^{\circ}C$, and 10.0, respectively. Kinetic analysis of the enzyme reaction under the optimal conditions showed that the values of $K_m$ and $V_{max}$ were 0.31 mM of ${\alpha}-linoleic$ acid and $384.16{\mu}mol$ of ${\alpha}-linoleic$ acid decomposed/min, respectively. The results indicate the reaction to be lipoxygenase-catalyzed oxidation of ${\alpha}-linoleic$ acid in AOT/isooctane reversed micellar system. The inhibitory effect of natural antioxidants on lipoxygenase showed little inhibitory effect of L-ascrobic acid while ${\alpha}-tocopherol$ showed 72% of inhibitory effect.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.183-190
• /
• 2011

This study was performed to assess the antioxidative properties of lipid from aquacultured mackerel Scomber japonicus fed with a diet fortified with conjugated linoleic acid (CLA) and ascidian Halocynthia roretzi tunic extracts by radical scavenging assay. The fish were separated into squid oil (Control) and 2.5% CLA (CA25) groups during the 8-week feeding period. The reducing power of each sample showed high levels of activity compared with ${\alpha}$-tocopherol and butylated-hydroxyanisol (BHA) at 0.2-1.0 mg/mL of lipid. Inhibition of linoleic acid oxidation in samples from Control and CA25 groups showed similar activity after 2 days of incubation at $40^{\circ}C$. The 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, and hydroxyl radical scavenging activities of CLA and carotenoid-deposited sample (CA25) were higher than those of the Control group. The results indicated that the lipid extracted from the viscera of mackerel showed slightly higher antioxidant activities than that from the muscle.

• Food Science of Animal Resources
• /
• v.20 no.4
• /
• pp.311-319
• /
• 2000

본 연구는 다기능성 지질신소재로 각광을 받고 있는 CLA를 육제품에 첨가하였을 때 제방의 산화를 억제시키는 효과에 대하여 연구하였다. 비육말기 돼지 사료에 LCA를 5% 첨가하여 생산한 동육 등심을 4$^{\circ}C$ 냉장고에에서 11일 동안 저장하면서 CLA 함량에 따른 지방산화정도(TBARS)에 대한 단순 상관도를 조사하였으며, 또한 CLA를 우욱 패티 제조에 0.05, r과 2%로 각각 첨가하여 제조한 후 4$^{\circ}C$에서 13일동안 저장하면서 pH, TBARS, 지방산 조성 및 CLA 함량을 조사하였다. TBARS의 단순상관도는 저장 11일째에 -0.804(p<0.001)으로 높은 상관관계를 나타낸 것으로 보아 CLA가 육내에 축적이 되면 저장 기간이 경과 할수록 지방산화를 지연시키는 것으로 나타났다. CLA가 육내에 축정이 도면 저장 기간이 경과 할수록 지방산화를 지연시키는 것으로 나타났다. CLA가 축정된 우육 패티를 soc장저장하면서 저장기간이 경과할수록 유의적으로 증가하였다.(P<0.05), 대조구에 비햐여 CLA 첨가구가 유의적으로 높은 pH를 보였으며,또한 CLA 첨가량이 증가할수옥 pH가 유의적으로 증가하는 현상을 보였다. (p<0.05). TBARS의 변화는 전 처리구에 저장 기간이 경과함에 EK라 유의적으로 증가하였다. (p<0.05)., 처리구간의 비교에서 대조구에 비하여 CLA 첨가구가 유의적으로 낮은 TBARS를 보였으며 (p<0.05), EH한 CLA펌가량이 증가할수옥 유의적으로 낮은 TBARS를 보여 CLA 가 항상화작용이 있음을 알수 있었다. CLA 우육 패티의 지방산 조성은 CLA 첨가량이 증가할수옥 상대적으로 다른 종류의 지방산 함량이 감소하는 겨과를 보였다. 저장기간이 경과에 따른 변화는 없었다. CLA 함량의 변화는 CLA첨가량이 증가할수록 유의적으로 증가하였으며(p<0.05) 저장기간이 경과하여도 아무런 변화가 없어 화학적으로 안정한 물질이라 사료된다. 이상의 결과에서 CLA는 지방산화를 억제시켜 산화 안정성에 효과가 있는 것으로 사료되며, CLA를 육제품 제조시 첨가할 경우 품질 보존 효과가 잇음과 동시에 고기능성 육제품 생산이 가능하리아 사료된다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.6
• /
• pp.853-858
• /
• 2010

The purpose of the study was to determine fat contents and fatty acid compositions of the lipids in sweetfish cultured in Korea and lipid oxidation during storage at refrigeration temperature ($2^{\circ}C$). Whole or minced sweetfish were vacuum-packaged or treated with ascorbic acid. Changes in thiobarbituric acid (TBA) values, peroxide values (PV) and free fatty acid (FFA) in the fish were determined. Sweetfish contained 72.5% moisture, 5.3% lipid and 1.1% ash. Palmitic acid was the highest (27.4% (w/w) of the total fatty acids) among the saturated fatty acids. Total monounsaturated fatty acids (MUFA) were 33.9% and oleic acid (21.0%) was the highest, followed by palmitoleic acid (7.8%). Total PUFA were 28.2%. Predominant PUFA were linoleic acid (8.1%), EPA (5.7%) and DHA (12.1%). TBA values and PV of the whole sweetfish treated with ascorbic acid and vacuumpackaged were not different from the control. TBA values of the minced sweetfish treated with ascorbic acid were significantly lower than the other groups (p<0.05). PV of the fish treated with ascorbic acid and vacuum packaging were significantly lower than the other groups (p<0.05). The result of this study suggests that cultured Korean sweetfish may be a good source of unsaturated fatty acids including EPA and DHA, and vacuum packaging and addition of ascorbic acid may protect lipids from oxidation.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.10
• /
• pp.1399-1404
• /
• 2006

Structured lipid (SL) containing conjugated linoleic and caproic acid was produced from soybean oil through lipase-catalyzed reaction, and its oxidative stability was compared. When heated at $60^{\circ}C\;or\;150^{\circ}C$, soybean oil as control was more susceptible to oxidation than SL. When the antioxidants, such as ascorbyl palmitate, tea polyphenol, alpha-tocopherol, and rosemary extract, were added in SL, the induction periods of each antioxidant treats in SL were increased. The tea polyphenol showed the most effective antioxidant activity among them. When the emulsion form with SL was heated from oxidation, its oxidation stability was reduced compared to SL. The oxidation stability were also observed in photooxidation of SL.

• Korean journal of food and cookery science
• /
• v.19 no.1
• /
• pp.60-64
• /
• 2003

Yukwa is a popular Korean traditional fried rice snack. The high fat content and porous structure of Yukwa cause it to become rancid rapidly. For extending the shelf-life of Yukwa, the Bandegi was fried with palm oil and soybean oil. The stability of Yukwa in lipid oxidation was determined by acid value(AV), peroxide value(POV), composition of fatty acid and sensory evaluation during 8 weeks of storage at 20$^{\circ}C$ and 50$^{\circ}C$ As the storage time increased, the AVs of soybean oil and palm oil during storage at 50$^{\circ}C$ were increased up to 42.64 and 2.09 mg/g, respectively. The POV of soybean oil during storage at 50$^{\circ}C$ was increased up to 4 weeks and then decreased. And as the storage time increased, the contents of stearic and oleic acid were increased, while linoleic and linolenic acid were decreased.

• Korean journal of food and cookery science
• /
• v.23 no.2 s.98
• /
• pp.180-186
• /
• 2007

In this study, we examined the effects of different water activities (Aw: 0.3, 0.5, and 0.8) on the lipid composition and oxidation of wheat flour after 28 days of storage in the dark at $60^{\circ}$C. The lipid content of the flour was 2.7%, and had decreased significantly (p<0.05) at the end of the storage period. Decrease in monoacylglycerol and increase in free fatty acids were observed, however, phosphatidic acid, phosphatidylglycerol, and phosphatidylinositiol were not detected after storage. Phosphatidylehtanolamine was more stable than phosphatidylcholine during the dark storage of flour. The flour lipids consisted of palmitic (18%), stearic (1%), oleic (14%), linoleic (63%), and linolenic (4%) acids, and the relative content of linolenic acid decreased after 28 days of storage. The conjugated dienoic acid content of the flour lipid had increased due to lipid oxidation during dark storage. Hydrolysis of neutral lipids and glycolipids, and lipid oxidation, were higher in the flour stored at Aw 0.8 than in the flour stored at Aw 0.3 or 0.5.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 1999.10a
• /
• pp.100-100
• /
• 1999

• Korean Journal of Food Science and Technology
• /
• v.25 no.4
• /
• pp.307-312
• /
• 1993

Antioxdant effect was studied in model system with linoleic acid methylester and tocochromanols $({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol\;and \;{\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$ under definite autoxidation condition-temperature $(40,\;60,\;80^{\circ}C),\;O_2\;(0,\;10,\;20%\;O_2\;in\;N_2)$. 13-Hydroperoxy-9-cis-11-trans-, 13-hydroperoxy-9-trans-11-trans-, 9-hydroperoxy-10-trans-12-cis-, 9-hydroperoxy-10-trans-12-trans-octadecadienoic acid methylester as the major oxidation product were produced from linoleic acid methylester by autoxidation, analyzed with HPLC and antioxidant activities were compared by their quantitative changes. Experimental results showed that all added tocochromanols except ${\alpha}-tocotrienol$ had antioxidant effect at $60^{\circ}C$, and also ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$ had prooxidant effect at $80^{\circ}C$. And cis/trans-hydroperoxide was predominantly produced at $40^{\circ}C$, but trans/trans-hydroperoxide at $80^{\circ}C$. Except no reproductive experimental data in produced hydroperoxides amount, the production ratio of cis/trans-:trans/trans-hydroperoxides in the autoxidation condition of range from $40^{\circ}C/10%,\;O_2\;to\;60^{\circ}C/20%\;O_2$ were as follows: ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$. This result showed that ${\alpha}-tocopherol$ among tocochromanols had the lowest antioxidant effect.

• Food Science and Biotechnology
• /
• v.16 no.5
• /
• pp.854-857
• /
• 2007

In this study, the crude methanol extract of mulberry leaves was fractionated with chloroform, ethyl acetate, n-butanol, and water, successively. The antioxidant activities of the fractions were examined with the 2-deoxyribose oxidation and linoleic acid peroxidation methods. The ethyl acetate fraction showed the strongest antioxidant activity. From it we isolated chlorogenic acid, caffeic acid, quercetin $3-O-{\beta}-D-glucopyranoside$, and kaempferol $3-O-{\beta}-D-glucopyranoside$ with preparatory octadecyl silane-high performance liquid chromatography (ODS-HPLC), and identified the compounds by nuclear magnetic resonance (NMR) and fast atom bombardment mass (FAB-MS) analyses. Overall, quercetin $3-O-{\beta}-D-glucopyranoside$ showed the strongest antioxidant activity by both the 2-deoxyribose oxidation and rat liver microsome peroxidation methods.