Seok-Joong Kang

Accumulation of Conjugated Linoleic Acid (CLA) in Tissues of Fish Fed Diets Containing Various Levels of CLA

Conjugated linoleic acid (CLA) is reputed to have anticancer activity and is provided by our food supply. The objective was to raise premium quality fish containing this anticancer ingredient. This study has examined the CLA accumulated in lipids extracted from tissues of fish cultured with diets mixed respectively with CLA at 1.0%, 2.5%, 5.0% and 10.0%. The CLA was made by an alkaline isomerization method applied to safflower oil. The major CLA isomers, cis-9, trans-11 and trans-10, cis-12-18:2 dominated the total lipid CLA accumulation at over 80%, with other isomers below 20%. In addition to total lipids, CLA was detected in phospholipids of tissue in fish. Fish (carp) in the group fed the 1.0% CLA diet showed growth slightly faster or similar to those in the control group, while those in test groups fed 5.0% and 10.0% CLA diets showed retarded growth. The proper amount of CLA additive has proven to be 1.0% when taking into account the feed efficiency and specific growth rate. However, addition of CLA by including 5.0% in the diet has been proven the most effective way to obtain a high content of CLA in fish edible muscle

Influence of Dietary Conjugated Linoleic Acid (CLA) and Carotenoids on Growth, Fatty Acid Composition, and 3T3-L1 Cells in Black Seabream ( Acanthopagrus schlegeli)

Three groups of black seabream (Acanthopagrus schlegeli) were fed with treatment diets containing certain concentrations of conjugated linoleic acid (CLA) and carotenoids. The control group feed contained 0% CLA and 0% carotenoids, the CP10 group feed contained 1% CLA and 0.1% carotenoids, and the CP25 group feed contained 2.5% CLA and 0.1% carotenoids . The CP10 and CP25 groups demonstrated the enhanced growth and increased feed conversion efficiency of black seabream. The specific growth rates (SGRs) were 0.74, 0.81, and 0.97, while the feed conversion ratios (FCRs) were 2.65, 2.46, and 2.04 for the control, CP10, and CP25 groups, respectively. The total contents of high unsaturated fatty acid (HUFA) for the control, CP10, and CP25 groups were 41.0%, 41.7%, and 43.5%, respectively. CLA was deposited to the extent of 2.8% and 5.6% in the muscle, and 4.0% and 8.3% in the viscera of the CP10 and CP25 groups, respectively. Meanwhile, treatment with the viscera lipid extract (VLE) from CP25 fish evidently lowered 3T3-L1 adipocytes viability. The lipid extract from the muscle and viscera of black seabream contained ample amounts of beneficial substances, such as CLA, carotenoids, EPA, and DHA. CLA, which enriched black seabream m uscle, could be categorized as a functional food and serve as a well-being food. Meanwhile, th e fish oil from its viscera could serve as a high function supplement.

Antioxidative Activity of Carotenoids in Mideodeok Styela clava

Abstracts Carotenoids were found in high levels in both muscle and tunic samples, with the highest and lowest values observed in March and January, respectively. The average values in muscle (GM) and tunic (GT) harvested in Geoje were 49.1 mg/100g and 56.7 mg/100g, respectively, whereas those in muscle (TM) and tunic (TT) harvested in Tongyeong were 42.0 mg/100g and 50.2 mg/100g, respec -tively. The total phenol contents of the tunic were not significantly different ( P < 0.05) between sampling area and month. We in-vestigated the antioxidative activities of the carotenoids against linoleic acid peroxidation [1,1-diphenyl-2-picrylhydrazyl (DPPH)] and hydroxyl radicals as well as their reducing power. The DPPH radical scavenging activity was 7.6-13.5% in GM, which is relatively weak, whereas it was 21.1-29.9% in GT, 9.6-12.4% in TM and 19.3-24.1% in TT. In comparison to α-tocopherol, the carotenoids were found to have strong inhibitory effects against linoleic acid peroxidation, and exhibited strong hydroxyl radical scavenging activities and reducing power at 120 μg/mL of each sample.

Lipid and Fatty Acid Composition in Nannochloropsis oculata Cultured in Varying Salinities

The quality and quantity of food organisms in fish seed production are important. The marine microalgae Nanno-chloropsis oculata are used as initial food organisms in the field. We investigated the effects of salinity(0,10,20,30,40 and 50 psu) on the lipid and fatty acid composition of N. oculata. Cultivation of N. oculata at varying salinities showed the highest growth rate at 20 psu. Total lipid content ranged from 17.26 to 18.63% at salinities from 0 to 50psu). The nonpolar lipid content increased markedly at 30 psu and was highest at 15.55%. The polar lipid content was lowest at 30 psu, by 84.45%. It was also found that the omega-3 and EPA contents were invesrsely proportional to salt concentration. For the polar and nonpolar lipid compositions, there was no singnificant effect of salinity. Omega-3 polyunsaturated fatty acid content especially the content of EPA in the seawater larvae is the essential fatty acid in this food organism. It is thus advantageous to culture N. oculata at 20 psu.

Effect of Growth Conditions on the Biomass and Lipid Production of Euglena gracilis Cells Raised in Mixotrophic Culture

유글레나는 엽록체를 가지고 광합성을 하는 점에서는 식물 로 취급하지만, 세포벽이 없고 편모로 유영생활을 하는 점에서 는 동물의 편모충류로 분류하기도 한다(Ruiz et al., 2004; Rodriguez-Zavala et al., 2010). 유글레나는 Vitamin E, Pramylon 와 같은 기능성 물질 뿐만 아니라 EPA와 DHA 같은 오메가-3 고도불포화지방산을 함유하고 있기 때문에 어류 자치어의 먹 이생물도 관심을 받고 있다(Harwood, 1988; Hayashi et al., 1993; James and Browse, 1999; Barsanti et al., 2000; Choi et al., 2013). 이들 기능성물질과 지방산의 함량은 자가영양배 양(autotrophic), 타가영양배양(heterotrophic) 및 혼합영양배 양(Mixotrophic) 배양조건에 따라서 달라진다(Wen and Chen, 2003; Wang et al., 2012). 즉 목적하는 기능성물질을 얻기 위해 서는 배양방법의 결정이 중요하다. 전보(Jeong et al., 2015)의 연구에 의하면 유글레나의 바이오매스와 오메가-3고도불포화 지방산의 함량 측면에서는 혼합배양방법이 최적배양방법인 것 으로 나타났다. 따라서 본 실험에서는 혼합영양배양 조건하에 서 배양온도와 pH와 같은 물리적 환경조건과 탄소원, 질소원 및 C/N비율과 같은 영양조건을 달리했을 때 따른 유글레나의 성장과 지질에 미치는 최적 배양조건을 구하고자 하였다. Mixotrophic 배양조건에 따른 Euglena gracilis의 성장과 지질에 미치는 영향 정우철·최종국·강창민·최병대·강석중*

Comparison of Fatty Acid Composition of Wild and Cultured Sea Cucumber Apostichopus japonicus

This study compared the fatty acid composition of wild and cultured specimens of the sea cucumber Apostichopus japonicus. We extracted total lipids from the specimens and determined their fatty acid compositions through capillary gas chromatography, resulting in the identification of 53 fatty acids....

Effect of Culture Conditions on Characteristics of Growth and Produc- tion of Docosahexaenoic acid (DHA) by Schizochytrium mangrovei

Both docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3) have attracted increasing attention since the first epidemiological report on the importance of n-3 essential fatty acids. Lipids in microbial cells play various biological roles and, consequently, much research has been carried out on their role in cell physiology. The lipid composition of microorganisms can exhibit considerable variations depending on environment. The effects of culture conditions, temperature (15, 20, 24, 28, 32 and 36℃), salinity (10, 20, 30, 40 and 50 psu), pH (pH5, 6, 7, 8 and 9), rotation speeds (50, 100, 150 and 200 rpm), carbon sources, nitrogen sources and C/N ratio on the production of docosahexaenoic acid, fatty-acid profiles, and acids secreted to the broth culture by the oleaginous microorganism, Schizochytrium mangrovei (KCTC 11117BP), were studied. Temperature (initially 28℃), salinity (20 psu), pH (pH7), rotation speeds (100 rpm), organism fatty acids, and secreted acids in the broth were varied during cultivation of S. mangrovei. At pH 7.0, S. mangrovei was able to accumulate lipids up to 40% of its biomass, with 13% (w/w) DHA content. The monosaccharides glucose and fructose, and yeast extract were suitable carbon and nitrogen sources, respectively. The primary omega-3 polyunsaturated fatty acid produced was docosahexaenoic acid.

Antioxidative Properties of Mackerel Scomber japonicus Fed a Diet Fortified with Conjugated Linoleic Acid and Ascidian Halocynthia roretzi Tunic Extract

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 α-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℃. 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.

Production of DHA-Rich Meats and Eggs from Chickens Fed Fermented Soybean Meal by Marine Microalgae (Schizochytrium mangrovei MM103)

The objective of this study was to evaluate the docosahexaenoic acid (DHA) levels of meats and eggs from chickens which were fed fermented soybean meal (FSM) by marine microalgae (Schizochytrium mangrovei MM103). The diets contained different amounts of FSM at 0, 3, 5 and 10%. DHA content of carcass was increased with dietary FSM. DHA amounts in the breast meat were higher in the 10% FSM diet (2.21%) than the 5% (1.65%) and 3% (1.18%) FSM, and similar results were observed in the leg meat (10% FSM: 2.21%; 5% FSM: 1.65%; and 3% FSM: 1.18%, respectively) and in eggs (10% FSM: 2.02%; 5% FSM: 1.22%; and 3% FSM: 0.73%). The level of n-3 polyunsaturated fatty acids such as DHA (22:6n-3) in the FSM treatment was significantly higher than those of the other groups (p<0.05). The results demonstrated that FSM by marine microalgae could be used to enhance DHA amounts in chicken meats and eggs.

Skin regeneration effect of the Glycosaminoglycans from Liparis tessellatus eggs

A purified Glycosaminoglycans (GAGs) extract from L. tessellatus eggs was enzyme-hydrolyzed and then fractionated with DEAE-Sepharose column chromatography. The fractions were subsequently subjected to skin regeneration effects analysis against skin fibroblast (CCD-986sk) cell lines. Fraction 3 is evidently to have tyrosinase inhibition activity by 20.1% at concentration of 50mg/mL. DOPA oxidation assay, collagenase inhibition activity assay, fibroblast proliferation assay, and production of type I C-peptide assays were done to further proof the skin regeneration effect of GAGs fractions. Results revealed that fraction 3 has effective skin regeneration activities at a concentration of 200mg/mL.