• 한국수산과학회지
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• 제39권3호
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• pp.283-291
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• 2006

This study examined the development of a low-salt fermented seafood product using an ascidian (Halocynthia roretzi), and the optimum processing conditions and quality characteristics of the low-salt fermented ascidian (LSA). The optimum processing conditions for the LSA were as follows. The ascidian was shelled and its muscle sliced into 5 mm widths. This was soaked in a 10% salt and 1% sodium erythorbate solution for 20 min. The solution was drained and then the muscle was soaked in 0.1% sodium bisulfite solution for 1 min. To this was added a 1:1 mixture of anchovy sauce and rice gruel, and it was fermented at $5^{\circ}C$ for 15 days. The moisture content and salinity of the LSA were 75.0-75.4% and 8.0-8.5%, respectively. During salt-fermentation at $5^{\circ}C$ for 20 days, the amino-N content of the LSA increased, and the texture softened gradually. The viable cell counts in early salt-fermentation were $4.2-4.5{\times}10^4CFU/g$, and this decreased gradually. The ratio of saturated fatty acids tended to increase in early salt-fermentation, while that of polyunsaturated fatty acids decreased slightly. Chemical experiments and sensory evaluation showed that the dipping treatment in 1% sodium erythorbate solution and 0.1% sodium bisulfite solution resulted in a good color and prevented browning of the salt-fermented ascidian meat. Moreover, adding anchovy sauce and rice gruel mixture improved the flavor of the LSA.

• 한국식품영양과학회지
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• 제27권4호
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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.

• Journal of Animal Science and Technology
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• 제44권1호
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• pp.45-54
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• 2002

본 내용은 미이용수산자원인 우렁쉥이 껍질의 성분상의 특성을 활용하여 착색제, 난각과 타우린 강화제로의 이용방법을 제시함으로서 폐기되고 있는 천연자원의 효율적인 재활용을 도모하는 한편, 합성색소의 생체기능학적 문제점을 해결하고 축산농가의 생산비 절감에 기여함을 그 목적으로 실시하였으며 실험결과는 아래와 같다. 산란계사료에 우렁쉥이 껍질을 1$\sim$5% 첨가했을 때의 산란율과 계란의 무게가 일반사료구(대조구)와 비슷한 경향을 보여 우렝쉥이 껍질첨가가 산란계의 산란성적에 영향이 없는 것으로 나타났다. 난황색도는 우렁쉥이 껍질 최소첨가량인 1$\sim$2% 첨가구에서 이상적인 Roche color fanscore (RCFS) 12$\sim$13 수준을 나타내고 3% 이상의 첨가구에서는 15 이상의 RCFS를 나타내어 첨가량이 증가할수록 카로티노이드의 축적량이 급격히 증가함을 알 수 있었으나 4% 이상에서는 축적률이 저조한 경향을 보였다. 계란 비중과 파괴강도는 일반란인 대조구의 경우는 점차 감소하거나 유지되었으나 우렁쉥이 껍질 첨가구는 급격히 증가하는 경향을 보였다. 이러한 효과는 2주부터 뚜렷하였으며 3주째에는 4% 첨가구의 경우 일반란보다 2.4% 비중이 증가한 것으로 나타나 전체적으로 우렁쉥이 껍질 첨가량이 증가할수록 난각의 파괴강도와 계란비중이 급격히 증가하였으나 4% 이상 첨가구에서는 그 증가폭이 감소하는 경향을 보였다. 계란 타우린 함량은 우렁쉥이 껍질 첨가량이 증가할수록 계란내 단백질 함량은 일정한데 비해 급격히 증가하는 경향을 보여 일반란인 대조구의 경우 18.53$\pm$3.09mg% 정도 함유되어 있는 반면 우렁쉥이 껍질 4% 첨가구인 경우 108.10$\pm$2.44mg% 정도 함유되어 있는 것으로 나타나 사료에 첨가한 우렁쉥이 껍질내 타우린(2.13%)이 계란으로 잘 이행되는 결과를 보였다. 전체 결과에 따라 우렁쉥이 껍질은 첨가량에 따라 산란계 사료용 합성 착색제를 대체할 수 있는 천연 착색제(색소원)로 사용 가능하며 부가적인 효과로 난각 강화 및 타우린이 강화되는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제23권1호
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• pp.163-166
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• 2002

• 한국수산과학회지
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• 제27권3호
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• pp.240-246
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• 1994

우렁쉥이 껍질 색소추출물을 이용한 무지개송어 체색 및 육색 침착효과를 검정하기 위하여 농도별, 기간별 급이실험을 하였다. 1. 체색의 개선효과는 사료급이 4주까지는 대조구와 비슷하였으나 6주후부터는 색소추출물 4(1,600ppm), 5구(3,200ppm) 및 pink구에서 효과가 나타났다. 명도(L)는 급이기간에 따라 감소하였으며 배측부위가 꼬리부위보다 약간 높았고, 적색도(a)는 8주후 꼬리부위가 배측부위보다 높아 색소추출물 4, 5구 및 pink구가 각각 4.7, 5.1, 5.9로 나타났다. 황색도(b)의 경우 배측부위는 감소하는 경향이었으나, 꼬리부위는 색소추출물 4, 5구 및 pink구는 증가하였지만 다른 구들은 변화가 적었다. 2. 육색의 개선효과는 체색의 개선효과보다 낮았으나 8주후에는 배측부위에서의 적색도(a)는 색소추출물 4, 5구 및 pink구가 각각 4.3, 4.6, 5.1로, 꼬리부위에서는 각각 4.7, 5.0, 5.4로 나타났다. 명도(L)는 색소추출물구가 증가한 반면 pink구는 거의 비슷하였다. 황색도(b)도 색소추출물구가 높아 전체적인 육색은 색소추출물구가 pink구보다 밝은 색을 띠는 것으로 나타났다. 3. 우렁쉥이 껍질 색소 추출물의 적정 투여량은 1,600ppm이상, 투여기간은 8주 이상이 되어야 할 것으로 나타났다.

• 한국발생생물학회지:발생과생식
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• 제15권1호
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• pp.1-7
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• 2011

It is suggested that FGF/Ras/MEK/Erk signaling plays crucial roles in specification and cell division of the mesodermal precursor cells in ascidian embryos. To investigate how the number of cell division in tissue precursor cells is determined, we have characterized Wee1 homolog, Hr-Wee1 of the ascidian Halocynthia roretzi. We found that the Hr-Wee1 mRNA is expressed both maternally and zygotically. Maternal transcript is localized to the cytoplasm in the animal cells, while zygotic expression is seen in cells of the endoderm lineage from 32-cell to 110-cell stages. Zygotic in situ signal is detected in the A-line neural plate cells of neurulae, and in epidermal cells of the head region of tailbud embryos. Embryos treated with MEK signaling inhibitor showed a similar pattern to normal embryos in expression of Hr-Wee1. Therefore, it is likely that MEK signaling does not affect the maternal and zygotic expression of Hr-Wee1.

• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.44-48
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• 2009

Nucleotide sequences of about 500 bp from the 5' end of mitochondrial (mt) DNA Cytochrome Oxidase I (COI) were analyzed to estimate the genetic variation between wild and cultured populations of the ascidian Halocynthia roretzi from two sites along the coast of Korea. A total of 25 haplotypes were defined by 21 variable nucleotide sites in the examined COI region. Genetic diversity (haplotype diversity and nucleotide divergence) of wild populations was higher than that of the cultured population. These data suggest that reduced genetic variation in the cultured population may have results from bottleneck effect caused by the use of a limited number of parental stock and pooling of gametes for fertilization. Pairwise population $F_{ST}$ estimates inferred that wild and cultured populations were genetically distinct. The combined results suggest that sequence polymorphism in the COI region would be preferable for estimating the genetic diversity of ascidian populations.

• KSBB Journal
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• 제28권1호
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• pp.36-41
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• 2013

Carotenoids are fat-soluble red-orange colored pigments found in plants and seafood-derived products, including algae, seaweeds, and fish muscle. In this study, we have demonstrated the molecular mechanism underlying the antioxidants and anti-inflammatory properties of ascidian tunic carotenoids using mouse macrophage cell line (RAW 264.7). Cell viability was not affected by treatment of carotenoids < 10 ${\mu}g/mL$. This treatment also showed negative inhibition on lipopolysaccharide (LPS)-stimulated nitric oxide (NO) and cyclooxygenase-2 (COX-2). The DPPH radical scavenging activity of carotenoids was 47.2% at 100 mg/mL. It also has a potential reducing power (1.025) comparable with ascorbic acid (1.584). The ascidian tunic carotenoids would make a candidate for the commercially interesting biologically active cosmetic pigments.

• 한국발생생물학회지:발생과생식
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• 제25권4호
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• pp.299-303
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• 2021

The ascidian Halocynthia aurantium (sea peach), a marine invertebrate, belongs to the same genus of the phylum Chordata along with the ascidian Halocynthia roretzi (sea pineapple), which is one of the model animals in the field of developmental biology. The characteristics of development and reproduction of H. aurantium are not yet known in detail. In order to find out the spawning period of H. aurantium, we investigated development of the gonads during the annual reproductive cycle. Testis and ovary were both in the bisexual gonads (ovotestes) of H. aurantium, which is a hermaphrodite like H. roretzi. In H. aurantium, the right gonad was longer and slightly larger than the left gonad throughout the year. In each gonad, the number of the testis gonoducts was slightly higher than that of the ovary gonoducts. These features were similarly observed in H. roretzi. However, the number of the testis gonoducts and the ovary gonoducts in each gonad of H. aurantium was about half that of H. roretzi. The gonads of H. aurantium contracted during the winter and summer seasons. The gonads decreased to the smallest size around February, and then started to increase again in March. The gonads were most developed in September of the year. Therefore, it is estimated that the spawning of H. aurantium begins around this period.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.389-397
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• 2013

FGF9/16/20 signaling pathway specify the developmental fates of notochord, mesenchyme, and neural cells in ascidian embryos. Although a conserved Ras/MEK/Erk/Ets pathway is known to be involved in this signaling, the detailed mechanisms of regulation of FGF signaling pathway have remained largely elusive. In this study, we have isolated Hr-Erf, an ascidian orthologue of vertebrate Erf, to elucidate interactions of transcription factors involved in FGF signaling of the ascidian embryo. The Hr-Erf cDNA encompassed 3110 nucleotides including sequence encoded a predicted polypeptide of 760 amino acids. The polypeptide had the Ets DNA-binding domain in its N-terminal region. In adult animals, Hr-Erf mRNA was predominantly detected in muscle, and at lower levels in ganglion, gills, gonad, hepatopancreas, and stomach by quantitative real-time PCR (QPCR) method. During embryogenesis, Hr-Erf mRNA was detected from eggs to early developmental stage embryos, whereas the transcript levels were decreased after neurula stage. Similar to the QPCR results, maternal transcripts of Hr-Erf was detected in the fertilized eggs by whole-mount in situ hybridization. Maternal mRNA of Hr-Erf was gradually lost from the neurula stage. Zygotic expression of Hr-Erf started in most blastomeres at the 8-cell stage. At gastrula stage, Hr-Erf was specifically expressed in the precursor cells of brain and mesenchyme. When MEK inhibitor was treated, embryos resulted in loss of Hr-Erf expression in mesenchyme cells, and in excess of Hr-Erf in a-line neural cells. These results suggest that zygotic Hr-Erf products are involved in specification of mesenchyme and neural cells.