• Journal of Aquaculture
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• v.17 no.3
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• pp.187-196
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• 2004

This study was carried out to investigate changes in biochemical composition of rotifer, Brachionus plicatilis, enriched with the commercial enrichments (Enhance, Advantage, Algamac-2000, DHA-Selco and Advantage ＋ Chlorella) at various durations of enrichment (0, 6, 12 and 24 hr) to improve the growth and survival of marine fish larvae. Total lipid content of rotifers enriched with various enrichments tended to increase with an increase in durations of enrichment up to 6 hr, but after that, was not significantly affected by enrichment materials. However, total protein content of rotifers enriched groups except for Advantage＋Chlorella decreased with the increase in duration of enrichment. The highest protein/lipid ratio showed 2.7 in rotifer enriched with the Advantage ＋Chlorella. The phospholipid/lipid ratio of rotifer enriched with the Enhance, Advantage and Advantage＋Chlorella groups was significantly higher than that of enriched rotifer with the Algamac-2000 and DHA-Selco groups. The highest DHA level, 2.5%, of rotifer enriched for 24 hr was obtained in the Advantage, but was not significantly different among other groups, except for Algamac-2000. No significant difference in DHA level of rotifer enriched with the DHA-Selco, Algamac-2000 and Advantage＋Chlorella groups was observed between l2h and 24hr of enrichment. The DHA/EPA ratio in the enriched rotifers varied among enrichment material groups, ranged from a high level of 11.1：1 in the Advantage＋Chlorella group to a low level of 4.1：1 in DHA-Selco group. The results from this study indicate that rotifers enriched with Enhance, Advantage and Advantage＋Chlorella seemed to be effective to improve nutritional value of rotifer for marine fish larvae because phospholipid, DHAJEPA and protein/lipid ratios of rotifer enriched with Enhance, Advantage＋Chlorella were higher than those of rotifer enriched with either DHA-Selco or Algamac-2000. Especially, supplementation of the Chlorella to these enrichments would appear to be effective for improvement of fish larval performance because of no reduction of protein level in rotifer, which is critical for growth of fish larvae.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1295-1306
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• 1998

Recent research indicates that the n-3 fatty acid , docosahexaenoic acid(22 : 6n 3, DHA) plays an essential role in infant brain development . DHA is highly concentrated in brain and retinal tissues and accumulates during late fetal and early neonatal life. Diets deficient in DHA are associated with reduced levels of DHA in brain and retinal tissues. The purpose of this study is to investigate the long term effects of DHA supplementation on the growth and mental development of full-term infants. THirty four healty infants were recruited from those who were delivered at Kyung Hee Medical Center. The experimental groups were the breast milk+DHA(-) group who were fed human milk for 20 weeks after birth and thereafter were fed placebo formula for 28 weeks, the breast milk+DHA(+) group who were fed human milk for 20 weeks after birth and thereafter were fed DHA supplemented formula for 28 weeks, DHA(-) group who were fed placebo formula for 48 weeks, and DHA(+) group who were fed DHA supplemented formula for 48 weeks. The daily average intake of DHA for the breast milk+DHA(-) , breast milk+DHA(+), DHA(-) and DHA(+) groups were 39.1mg, 89.9mg, 17.7mg, and 160.224mg, respectively. The results showed that measurements of infant weight, length, head, and chest circumferncewere all in normal range and they were not influenced by the DHA supplements in their diets. There was a significant correlation between dietary DHA intake and erythrocyte DHA level. The results of flash visual evoke potential (VEP) test were not correlated with eerythrocyte DHA and dietary DHA levels at 48 weeks of age. No differences were found in Bayley mental and Psychomotor Development lndex scores among the four experimental groups at 48 weeks of age. Unlike the short-term effects there was no long-term effect of relatively small amounts of dietary DHA supplements on the scores for flash VEP and Bayley test, even thour호 there was an elevated DHA supplements on the scores for flash VEP and Bayley test, even through there was an elevated DHA content in the infants erythrocytes.

• Korean Journal of Poultry Science
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• v.35 no.3
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• pp.255-265
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• 2008

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.

• Korean Journal of Poultry Science
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• v.39 no.1
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• pp.1-8
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• 2012

To evaluate the effects of n-3 and n-9 fatty acid combination on broiler chicks, diets containing the combinations of five different fat sources including flaxseed oil, fish oil, EPA, DHA and olive oil were provided, and all chicks were processed at 4 weeks of growth. Liver, breast and thigh samples were collected and fatty acid composition and/or CIE $L^*$, $a^*$ and $b^*$ measurement were measured. Also, live chick and liver weights were weighed and the ratio was provided as an evidence of fat accumulation in liver. No significant difference was determined in both live and liver weight ratio and liver color. EPA was low in FHO as compared to livers from others. In contrast, DHA was significantly high in FHO. In broiler breasts derived from FDO, AA and n-3 fatty acid content was high, but only numerical differences of EPA and DHA were determined in breasts from FDO. The thighs from FHO showed high in EPA, DHA and n-3 fatty acid content but had low in AA and n-6 to n-3 ratio. Therefore, the results indicate that broiler chicken diets containing either FDO or FHO may be possible combination diets increasing n-3 polyunsaturated fatty acids in broiler chicks.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.143-148
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• 1994

The relationships between microbial activity and physico-KDICical characteristics of soils were investigated in three golf courses of Kwanak, Gold and Korea Country Clubs, with different open years. The soil samples were collected in tee, fairway and rough. There were ranges of 4.80-5.55 in pH, $25.55-98.50{\mu}S$ / cm in conductivity, 10.96-16.73% in moisture content, 0.18-0.36g / g in water holding capacity, 3.68-5.39% in organic matter, and 0.10-0.25% in total nitrogen. Dehydrogenase activity(DHA) as an index of soil microbial activity was determined. DHA values of soil were $69.83-314.43{\mu}$g / g in three courses and showed the order of Kwanak>Gold>Korea Country Club with open year. This indicates that DHA was affected by several fertilizer treatments rather than herbicide and pesticide treatments. DHA was significantly different with golf clubs as well as golf courses and positively correlated with water holding capacity and total nitrogen.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.4
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• pp.467-473
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• 2016

Several of our recent studies have focused on mass production of the marine Cladoceran Diaphanosoma celebensis, which can serve as a feed substitute for Artemia nauplii in the culture of larval marine fish. We compared the growth and survival rates of tiger puffer Takifugu rubripes fed D. celebensis with those fed Artemia. The group fed D. celebensis showed an increase in growth from 0.10 g to 1.78 g, while the group fed enriched Artemia had a growth from 0.10 g to 0.92 g. The survival rate of fish fed D. celebensis was 86.7% while that of fish fed enriched Artemia was 51.1%, indicating that the former group was superior to the latter both in growth and survival rate. Fatty acid analysis revealed that D. celebensis fed Nannochloropsis oculata and Schizochytrium sp. had an eicosapentaenoic acid (EPA) content of 16.42% and a docosahexaenoic acid (DHA) content of 3.93%. Meanwhile, juvenile tiger puffer fed D. celebensis had an EPA content of 9.12% and a DHA content of 10.69%. Juvenile tiger puffer fed D. celebensis had a similar n-3 highly unsaturated fatty acid content to that of tiger puffer fed enriched Artemia which had an EPA content of 5.82% and a DHA content of 15.90%, indicating that no additional enrichment was required.

• Journal of Nutrition and Health
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• v.26 no.6
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• pp.661-671
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• 1993

The change in fatty acid composition in brain tissue of the second generation rats(Sprague-Dawley strain) was studied using four different fat diets(Corn oil=CO, Soybean oil=SO, Perilla oil=PO, Fish oil=FO, 10% by Wt). The experimental diets were started from pregnancy in four different groups, each consisting of 9 rats. The seound generation rats were fed the same diet as their mothers. Animals were anesthetized with ether at 0, 3, 9 & 16 weeks of age. Whole brains were dissected out, brain tissues were, then, homogenized and lipids were extracted from brain tissues. The fatty acid compositions were measured after methylation by gas-liquid chromatography at 0, 3, 9 and 16 weeks of age of offspring. The changes in the relative concentrations of polyunsaturated fatty acids(PUFA) or more specifically docosahexaenoic acid(22 : 6, $\omega$3, DHA), the major $\omega$3 fatty acid component in rat brain at different age were similar to changes in the amount of DNA in brain tissue showing the maximum value during the lactation. The changes in saturated fatty acid(SFA) content showed a contrasting patten to those of PUFA, while monounsaturated fatty acid(MUFA) increased steadily throughout the experimental period. At birth, the relative concentrations of $\omega$3 series fatty acids the relative concentrations of PUFA, MUFA and SFA converged to very similar values respectively regardless of the dietary fatty acid compositions. In brain tissue, it is of value to note that while changes in relative concentrations of linoleic acid (18 : 2, $\omega$6, LA) and arachidonic acid(20 : 4, $\omega$6, AA) showed a precursor-product-like relationship, $\alpha$-linolenic acid(18 : 3, $\omega$3, $\alpha$-LnA) and DHA showed a different pattern. Even when the $\omega$3 fatty acid content in very low in maternal diet(CO), the second generation rat brain tissues appeared to secure DHA content, suggesting an essential role of this fatty acid in the brain. The fact that a large amount of $\alpha$-LnA in the maternal diet did not have a significant effect on the second generation rat brain $\alpha$-LnA content, indicated that DHA seemed essential component for the brain development in our experimental condition. In all groups, the relative content of $\alpha$-LnA in the brain tissues remained relatively constant throughout the experimental period at the very low level. The study of the specific concentrations and essential role(s) of DHA in each parts of brain tissue is needed in more details.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.184-188
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• 2002

The fatty acid contents of egg yolk from various chicken eggs such as general egg, ginseng egg, gamgoal egg and docosahexaenoic acid (DHA) egg were analysed during storage at 4$^{\circ}C$ for 3 weeks. The major fatty acids of all egg yolk oils were oleic acid (18 : 1) and palmitic acid (16 : 0). The contents of both fatty acids reached maximum at the first or second week and decreased at the third week. DHA was detected from 4 kinds of eggs stored for 2 or 3 weeks. The n-6/n-3 ratio was obtained under recommended intake range in fresh gamgoal egg and in general and DHA eggs stored far 0~3 weeks. For 3 weeks, polyunsaturated fatty acid / monounsaturated fatty acid/ saturated fatty acid (P/M/S) ratio of DHA e99 did not chance, but that of ginseng e99 gradually increased. The P/M/S ratio was generally maintained under recommended intake range in general egg stored for 3 weeks, in ginseng egg stored for 2 weeks and in DHA egg during all the storage period.

• Microbiology and Biotechnology Letters
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• v.33 no.1
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• pp.51-55
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• 2005

The effect of rotation speed and culture temperature on the growth of T. aureum and also the biosynthesis of lipid and DHA was investigated. The optimal temperature for the growth was $32^{\circ}C$, but the best temperature for the maximum production of lipid and DHA was $18^{\circ}C$ in the range of $4^{\circ}C\;to\;39^{\circ}C$. In the case that the temperature was higher than $39^{\circ}C$ and lower than $11^{\circ}C$, the growth was very slow and the production of DHA was also very low. However, the lipid content in the biomass became higher with decrease in the culture temperature. The rotation speed for the maximum growth was 100rpm. But the growth and the production of DHA were not affected by the change of rotation speed in the range of 100 to 250 rpm. When the rotation speed was 50 rpm, the growth as well as the production of DHA and lipid was greatly reduced.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.890-894
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• 1988

The baking quality of flours produced from Dark Northern Spring(DNS). Hard Red Winter(HRW) and Australian Standard White(ASW) were examined. To improve the baking quality of HRW and ASW, oxidants such as dehydroascorbic acid(DHA) and potassium bromate$(KBrO_3)$ were added. The protein content of HRW was about 3% higher than that of ASW but the specific volume of the baked gluten extracted from HRW and ASW were nearly same. By addition of DHA 100ppm and $KBrO_3$ 50ppm as oxidants to HRW and ASW, the farinogram's stability was strengthened and departure time, time to breakdown were extended. The specific volume of the bread based on HRW was very small but it was improved significantly by addition of oxidants. According to the quality scoring of bread, the breads based on DNS, HRW and ASW were 93, 72 and 75, respectively. The baking quality of HRW was improved by DHA and $KBrO_3$ but not much in ASW.