• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.240-246
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• 1994

This study was designed to determine the optimum pigment concentration supplemented in diet and feeding periods on the pigmentation of rainbow trout(Oncorhynchus mykiss) by using acetone-extracts of ascidian tunic as a natural pigment source. The eight pigmented diets contained carotenoid of ascidian tunic extracts at concentrations of 0, 200, 400, 800, 1,600 and 3,200mg/kg of diet, carophyll pink at concentration of 800mg/kg and commercial diet. No difference in pigment concentration was found between the ascidian extracts group and the control group until 4 weeks, but the redness of muscle and integument in the 1,600, 3,200mg/kg diet and carophyll pink was increased in the dorsal and caudal areas of fish from 6 weeks of age. In the sensory panel test, fish fed the ascidian tunic extracts diet were similar to those fed the carophyll pink diet. The optimum concentration and feeding periods for pigmentation of rainbow trout was found to be ascidian tunic extracts of 1,600mg/kg diet for 8 weeks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.393-408
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• 1996

The effect of various levels of ascidian tunic extracts and carophyll pink on the growth rate, pigmentation, lipid and total cholesterol accumulation, and fatty acid compositions were studied in kuruma prawn, Penaeus japonicus. The kuruma prawn was fed the purified diets with or without ascidian tunic extract and carophyll pink at the levels of 100, 200, and 400 ppm for 8 weeks. In the experiment diet with ascidian tunic extracts or carophyll pink, the values of daily growth rate were ranged between $1.065\;to\;1.292%$, compared with control group. The content of astaxanthin in kuruma prawn was not significantly affected by the feeding levels of tunic extracts. Feeding of the tunic extracts, on the other hand, increased the kuruma prawn lipid and total cholesterol content, and pigment deposition in concentration-dependent manners without influencing the free astaxanthin concentration of prawn flesh and heads between two feeding groups(200 and 400 ppm). And it was also demonstrated that the dietary astaxanthin was deposited in kuruma prawn body tissue mainly as astaxanthin esters. The results suggest that the best feeding strategy for pigmentation in kuruma prawns is the diets with ascidian tunic extracts at the level of 4g/kg feed (200 ppm) for 8 weeks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.581-588
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• 2010

To examine the functional properties of conjugated linoleic acid (CLA) and ascidian tunic extracts in fish, we compared mackerel fed ascidian tunic extract and CLA (CA25) and a control group. The daily growth index of CA25 was 1.92 compared to 1.86 in the control group. The viscerosomatic index of CA25 was 36.7% lower than that of the control group. After 8 weeks, the protein content decreased from 19.7 to 17.5% in the CA25 group. The ascidian tunic extract content in the viscera was much higher than in muscle (0.13 vs. 0.03 mg/100 g) after 8 weeks. At the start, the n-3 fatty acid content of the experimental fish was 25.2% in muscle and 23.7% in viscera. The CLA content in muscle in the CA25 group was 2.1% after 4 weeks and 2.3% after 8 weeks. By contrast, the CLA content in viscera did not change after 8 weeks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.351-356
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• 1994

The stability of carotenoid extracts from ascidian, Halocynthia roretzi, tunics during heating and solvent storage was examined. After 4 hours of heating at $100^{\circ}C,\;10\%$ of total carotenoids was decomposed. The stability of carotenoid extracts were determined in 4 organic solvents. Stability was checked for 1, 2, and 4 weeks at room temperature($15{\pm}2^{\circ}C$), $4^{\circ}C$, and $-20^{\circ}C$ by measuring absorbance. B7(alloxanthin) and B10(halocynthiaxanthin) were more stable than the other carotenoid components. The stability of carotenoid extracts from ascidian tunic was dependent on storage temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.721-724
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• 2009

Astaxanthin is a valuable pigment source for many aquacultured species, including salmonoids, shrimp, sea bream, and ornamental species. Conjugated linoleic acid (CLA) and ascidian tunic extracts were mixed with the basal diet of rainbow trout to investigate their pigmentation effects. Synthetic Carophyll Pink and natural carotenoids that came from the tunic extracts were incorporated into muscle and skin tissues. The main carotenoids found in muscle after 8 weeks were canthaxanthin in CP12 (13.4%), and CP52 (17.2%), and astaxanthin in CP12 (58.5%), and CP52 (59.2%) in the Carophyll Pink group, while those in skin were canthaxanthin in CP14 (34.5%), and CP54 (29.2%), and astaxanthin in CP14 (32.0%), and CP54 (36.5%) in the ascidian tunic extract group. The total carotenoid content in skin (53.0-69.3 mg/kg) was greater than that in muscle (9.5-13.8 mg/kg).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.445-453
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• 1994

Rainbow trout, Oncorhynchus mykiss, were cultured with different levels of carotenoids in odor to investigate the feeding effect of ascidian tunic extracts on the liver fatty acid compositions of them. Dominant monoenoic fatty acids of the ascidian tunic extracts were 16:1n-7($5.9\%$), 18:1n-9($21.9\%$), and 18:1n-7($3.5\%$) and polyenoic fatty acids of them were linoleic(18:2n-6, $14.2\%$), eicosapentaenoic(20:5n-3, $3.5\%$), and docosahexaenoic acid(22:6n-3, $8.3\%$). The compositions of fatty acid in the liver lipids were affected by the tunic extract levels during the feeding. The percentage of monoenoic acids in extract diets was decreased, and that of n-3PUFA was increased during feeding 2 weeks. But the n-3PUFA contents were decreased in 4 weeks. The 20:4n-6 content in rainbow trout fed extract diet was higher than that in the control and pink diet groups. The rainbow trout fed with ascidian tunic extracts showed an increase of essential fatty acids in the fish tissue, compared to the control or pink diet feeding groups.

• Journal of Nutrition and Health
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• v.11 no.3
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• pp.13-20
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• 1978

Changes of free amino acids, nucleotides and their related compounds as taste compounds during sun drying of ascidian Cynthia roretzi, were analyzed by amino acid autoanalyzer and high speed liquid chromatography. In fresh ascidian, the results showed that 5'-UMP $(12.1\;{\mu}mole/g)$ was dominant and the content of cytosine, 2', 3'-CMP, 2', 3'-GMP, hypoxanhtine, 5'-AMP,5'-IMP were 5.8, 3.4, 3.1, 2,3, 1.7 and $1.3\;{\mu}mole/g$ ondry base respectively. 5'-IMP, 2', 3'-CMP and 2', 3'-GMP tended to degrade slowly and 5'-AMP, cytosine and 5'-UMP were decreased rapidly while hypoxanthine were increased remarkably during the sun drying. In dried ascidian, the content of hypoxanthine was the highest, 7.2 mole/g on dry base, whereas that of 5'-AMP $(0.5\;{\mu}mole/g)$) and 5'-IMP $(0.9\;{\mu}mole/g)$ were lower. Glutamic acid, alanine and serine were dominant amino acid in the fresh extracts, having 22.4% (611.3mg%, on dry qase), 19.8% (540.5mg%) and 14.8% (402.8mg%) of the total amino acid content respectively. The content of tyrosine, histidine, lysine, methionine, isoleucine and valine were low, and proline, phenylalanine were detected in trace amount. The free amino acid were not changed in composition but the increase of total free amino acid was approximately 116.8mg% during sun drying. In sun dried ascidian, glutamic acid (691.0mg, on dry base), alanine (641.3mg%), serine (469.5mg%), threonine (234.8mg%) and glycine (206.3mg%) were dominant amino acid. It is believed that glutamic acid, serine, alanine, threonine, glycine and hypoxanthine play an important role as taste compounds in sun dried ascidian.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.603-608
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• 1998

Lipid oxidation in ascidian was studied when fresh, deshelled and sliced meats were fermented for 50 days at 5$\pm$2$^{\circ}C$ with 8%(w/w) salt and 0.1% papain. Antioxidative effects of butylated hydroxytoluene(BHT) and carotenoid extracts from ascidian tunic on lipid oxidation and oxidationrelated discoloration of ascidian meat during fermentation were investigated. Changes in peroxide value, carbonyl value, thiobarbituric acid value, fatty acids composition, the loss of total carotenoid and sensory evaluation were determined to assess the rancidity. Peroxide and carbonyl values in BHT and carotenoid extract treatments increased less than those of the control during fermentation. TBA value increased until 30 days, hereafter tended to decrease a little in the control during fermentation. TBA value increased until 30 days, hereafter tended to decrease a little in the control but it increased slowly until 40 days in cases of 0.02% BHT or 0.02% BHT with 0.05% carotenoid added. Fatty acids of fresh ascidian composed of polyenoic acid, saturated acid and monoenoic acid of 51.5%, 28.1% and 20.7%, respectively. Saturated fatty acids(C16:0, C14:0, C18:0) and monoenoic acids(C18:1, C16:1) increased while polyenoic acids(C20:5, C22:6) decreased during fermentation. Carotenoid was markedly degraded and discolored in the control during fermentation. But 0.02% BHT and 0.05% carotenoid treatments had bright color like fresh meat during 40 days. The results of sensory evaluation during the fermentation also convinced the retard of discoloration by the addition of BHT and carotenoid.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.232-239
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• 1994

In order to determine the utilization of ascidian tunic, which has been blamed for problems of costal environmental pollution when discharged into the sea after being used as a natural dietary pigment sources for rainbow trout(Oncorhynchus mykiss), fingerlings were fed on experimental diets containing acetone-extracts for 6 weeks. The amounts of acetone-extracts were 11,000mg/Kg and contained 50mg/100g wet tissues of carotenoid and $6\%$ of carotenoids were astaxanthin. From the results of feeding experiments, the growth rate in the extract group was a little higher than that of the control and pink groups after 6 weeks. The redness and yellowness of the fish skin and muscle in the extract group were similar to the pink group. Therefore, acetone-extracts of ascidian tunic were judged to be a natural dietary pigment source suitable as a substitute synthetic pigment for aquaculture use.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.357-368
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• 1996

To utilize the ascidian tunic as a natural pigment and dietary sources for rainbow trout (Oncorhynchus mykiss), juvenile were fed on experimental diets containing enzymatic hydrolysates of ascidian tunic treated with three commercial mined enzymes (ultrazyme, cellulase, viscozyme) for 12 weeks. From the results of feeding experiment, similar growth rate was checked in the enzymatic hydrolysis group compared with control, and those were a higher than of ascidian tunic powder group. The total acetone extractable pigment in muscle of the enzymatic hydrolysates group was lower than that of the ascidian extracts group and carophyll pink group until 8 weeks, but the level of those pigment of the enzymatic hydrolysates was similar to the ascidian extracts and carophyll pink group after 12 weeks. The lipid content was increased with the pigment concentration in the all experimental group. But the ascidian tunic pigment did not influence on the composition of the fatty acids in the muscle and liver. From the consideration of results for pigmentation, the enzymatic hydrolysates of ascidian tunic were suitable for both a natural pigment and dietary protein and carbohydrates sources as a substitute synthetic pigment for aquaculture use.