• Journal of Environmental Science International
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• v.23 no.1
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• pp.89-96
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• 2014

Styela clava tunic is generated in large amounts as a waste from S. clava processing plants and causes environmental problem. Although biological activities of S. clava were reported by many investigators, study on S. clava tunic was little. In this study, therefore, tyrosinase inhibition and antioxidative activities of extracts from S. clava tunic using different solvent were investigated for recycling of the fishery waste. Among extraction methods tested, autoclaved extraction (25.7%) and hot water extraction (18.2%) appeared to be effective for extraction. The highest total phenolic content was 46.6 mg/g in autoclaved extract while the highest flavonoid content was 23.0 mg/g in chloroform extract. All extracts possessed tyrosinase inhibition activity and the inhibition activity was concentration-dependent. Inhibition concentration ($IC_{50}$) against tyrosinase activity was $0.36{\times}10^4$ mg/ml in ethanol extract, $0.11{\times}10^3$ mg/ml in acetone extract and 0.27 mg/ml in n-butanol extract. Among extracts tested, hot water and autoclaved extracts displayed higher antioxidative activity than organic solvent extracts. Therefore, our data suggest that extract from S. clava tunic may potential candidate for cosmetic product with whitening effect and medicine for diseases caused by various oxidative stresses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.908-911
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• 2006

Fish paste containing Styela clava (Korean name: miduduk) was prepared for the supplementary value of the product, and it was evaluated for the color, textural properities, and sensory attributes. Increasing the amount of S. clava in the fish paste tended to increase the lightness (L), the redness (a), and the yellowness (b) in Hunter color values. All test samples with 3 mm thickness had good flexibility and did not break even after 4 times folds. Fish paste containing 20% S. clava showed the highest values in strength, hardness, and adhesiveness. In overall acceptance of sensory evaluation, fish paste containing 5% S. clava did not show any difference in comparison with non added control. These results suggest that S. clava can be applied to fish paste products to improve the quality and functionality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.278-283
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• 2006

Styela clava was processed by four different kinds of method including FR (fresh S. clava), H1 (heat treated S. clava at $110^{\circ}C$ for 15 min) H2 (heat treated S. clava at $120^{\circ}C$ for 5 min), and FD (freeze dried S. clava). Each S. clava sample was treated with methanol, ethanol, acetone, and water, then antioxidant and anticancer activities of the extracts were evaluated. In extracts from non-dried S. clava (FR, H1, and H2), total extract yield decreased with increasing treated temperature. The extraction yield was in the order of ethanol>methanol>water>acetone among treated solvents. In case of dried S. clava (FR), the extraction yield was lower than non-dried samples, and was in the order of methanol>ethanol>water>acetone. The radical scavenging activity (RSA) of non-dried S. clava (FR, H1, and H2) was in the order of acetone>ethanol>methanol and heat treatment also decreased RSA. RSA of FD was the highest in ethanol extract, while acetone and water extracts did not show RSA. When antioxidant activity was determined by reducing power (RD), methanol extract of FR showed the highest values and heat treatment decreased RD, too. RD of FD was in the order of methanol>ethanol>water>acetone. The acetone extracts from FD showed significant anticancer activity against human colon cancer cell line HT-29. These results indicated that extraction yield and properties of extracts from S. clava were dependent on processing temperature, solvent and/or physicochemical state. The appropriate extraction process should provide some valuable bioactive materials from S. clava.

• Fisheries and Aquatic Sciences
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• v.20 no.7
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• pp.14.1-14.8
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• 2017

In this study, marine tunicate Styela clava hydrolysate was produced by an environment friendly and green technology, pressurized hot water hydrolysis (PHWH) at different temperatures ($125-275^{\circ}C$) and pressure 50 bar. A wide range of physico-chemical and bio-functional properties such as color, pH, protein content, total carbohydrate content, reducing sugar content, and radical scavenging activities of the produced hydrolysates were evaluated. The appearance (color) of hydrolysates varied depending on the temperature; hydrolysates obtained at $125-150^{\circ}C$ were lighter, whereas at $175^{\circ}C$ gave reddish-yellow, and $225^{\circ}C$ gave dark brown hydrolysates. The $L^*$ (lightness), $a^*$ (red-green), and $b^*$ (yellow-blue) values of the hydrolysates varied between 35.20 and 50.21, -0.28 and 9.59, and 6.45 and 28.82, respectively. The pH values of S. clava hydrolysates varied from 6.45 ($125^{\circ}C$) to 8.96 ($275^{\circ}C$) and the values were found to be increased as the temperature was increased. The hydrolysis efficiency of S. clava hydrolysate was ranged from 46.05 to 88.67% and the highest value was found at $250^{\circ}C$. The highest protein, total carbohydrate content, and reducing sugar content of the hydrolysates were found 4.52 mg/g bovine, 11.48 mg/g and 2.77 mg/g at 175, and 200 and $200^{\circ}C$, respectively. Hydrolysates obtained at lower temperature showed poor radical scavenging activity and the highest DPPH, ABTS, and FRAP activities were obtained 10.25, 14.06, and 10.91 mg trolox equivalent/g hydrolysate (dry matter basis), respectively. Therefore, S. clava hydrolysate obtained by PHWH at $225-250^{\circ}C$ and 50 bar is recommended for bio-functional food supplement preparation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1591-1595
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• 2012

Styela clava (Korean name: miduduk) tunic was produced as a byproduct after processing of S. clava. To utilize S. clava tunic, fish paste containing tunic powder was prepared, and quality characteristics were evaluated for color, textural properties, and sensory attributes. Increasing the amount of S. clava tunic in fish paste tended to decrease lightness (L), redness (a), and yellowness (b) values of the surface part of fish paste. Strength and hardness of fish paste increased with increasing amount of tunic. All test samples with 3 mm thickness showed good flexibility and did not break even after folding in half four times. For overall acceptance in the sensory evaluation, fish paste containing 1% S. clava tunic acquired a relatively higher score. These results suggest that S. clava tunic can be applied to fish paste products to improve quality and functionality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.2
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• pp.274-279
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• 1995

Seasonal variation of the taste components such as free amino acids, nucleotides, quarternary ammonium bases, and guanidino compounds in warty sea squirt(S. clava) were determined bimonthly from April to October for its food quality contributed in Korean seafood dishes. Fifty to sixty two percentage of the extractable nitrogen was free amino acids, and mainely it composed of taurine, proline, glutamic acid, glycine and glycinebetaine. Among the various taste component, betaine's level was somewhat higher(11~15%) and nucleotides related compounds also followed(5~8%). Most of nitrogenous compounds in the extractives reached to a maximum value in June and AMP content was relatively higher than the other nucleotides. The major organic acids were composed of succinic acid, malic acid, lactic acid and pyroglutaric acid in S. clava. The result of omission test suggested that the taste of S. clava is mainly attributed to free amino acids, betaines, nucleotides and non-volatile organic acid in order.

• Textile Coloration and Finishing
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• v.29 no.1
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• pp.45-54
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• 2017

Ultraviolet radiation have much influenced with a deep wrinkles, roughness, laxity of skin damage and pigmentation through oxidative stress and oxidative photo-damage. This study investigates the functional properties of hydrogel facial mask sheets made from agar, Styela clava tunics and Broussonetia papyrifera tunics. The skin of S. clava is covered with a hard cellulose containing glycoprotein, glycosaminoglycan and chondroitin sulfate. B. papyrifera is better known as Paper mulberry. It contains kazinol which serves as a tyrosinase inhibitor and skin whitening agent. The tensile strength of facial mask sheet was measured by universal testing machine, and the water absorption and moisture permeability of facial mask sheet were measured by dryer. Additionally, the DPPH assay and MTT assay were conducted for anti-oxidative activity and cytotoxicity of facial mask sheet. The whitening effect of the facial mask sheet was measured by tyrosinase inhibitor assay. These tests showed that the three ingredients are suitable cosmetic materials. The results reveal that they produce a high quality hydrogel facial mask sheet when the membrane contains 1%(W/V) of agar, 0.1%(W/V) of B. papyrifera tunics and 0.05%(W/V) of S. clava tunics.

• Nutrition Research and Practice
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• v.9 no.3
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• pp.219-226
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• 2015

BACKGROUND/OBJECTIVES: In this study, potential anti-inflammatory effect of enzymatic hydrolysates from Styela clava flesh tissue was assessed via nitric oxide (NO) production in lipopolysaccahride (LPS) induced RAW 264.7 macrophages and in vivo zebrafish model. MATERIALS/METHODS: We investigated the ability of enzymatic hydrolysates from Styela clava flesh tissue to inhibit LPS-induced expression of pro-inflammatory mediators in RAW 264.7 macrophages, and the molecular mechanism through which this inhibition occurred. In addition, we evaluated anti-inflammatory effect of enzymatic hydrolysates against a LPS-exposed in in vivo zebrafish model. RESULTS: Among the enzymatic hydrolysates, Protamex-proteolytic hydrolysate exhibited the highest NO inhibitory effect and was fractionated into three ranges of molecular weight by using ultrafiltration (UF) membranes (MWCO 5 kDa and 10 kDa). The above 10 kDa fraction down-regulated LPS-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), thereby reducing production of NO and prostaglandin $E_2$ ($PGE_2$) in LPS-activated RAW 264.7 macrophages. The above 10 kDa fraction suppressed LPS-induced production of pro-inflammatory cytokines, including interleukin $(IL)-1{\beta}$, IL-6, and tumor necrosis factor $(TNF)-{\alpha}$. In addition, the above 10 kDa fraction inhibited LPS-induced phosphorylation of extracellular signal-regulated kinases (ERKs), c-Jun N-terminal kinase (JNK), and p38. Furthermore, NO production in live zebrafish induced by LPS was reduced by addition of the above 10 kDa fraction from S. clava enzymatic hydrolysate. CONCLUSION: The results of this study suggested that hydrolysates derived from S. clava flesh tissue would be new anti-inflammation materials in functional resources.

• Journal of Life Science
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• v.18 no.1
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• pp.109-113
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• 2008

For useful basic data in new ascidian processed products, this study investigated and compared the biological activities of two ascidians, Styela clava and Styela plicata, in two conditions with fresh one and cooking one at $100^{\circ}C$ for 10 min. By fresh state, Styela clava (8.46 mg/ml) had higher activity than Styela plicata (13.67 mg/ml) in the antioxidative assay ($EDA_{50}$), whereas Styela plicata (10.54 mg/ml) had higher than Styela clava (12.05 mg/ml) after cooking. Particularly the antioxidative activity of Styela plicata increased 1.3 times after cooking. Fresh Styela clava had antimicrobial activity against Bacillus subtilis, B. cereus, E. coli, whereas the activity appeared against E. coli only after cooking. However, antimicrobial activity in Styela plicata appeared against 4 gram positive bacteria (B. subtilis, B. cereus, S. aureus and L. monocytogenes) and E. coli, regardless of concentration level (1,000-1,500 ppm) and with/without cooking. ACE inhibitory activity was not observed in the samples. By cooking, the level of fibrinolytic activity increased to 1.79 from 1.24 plasmin unit/ml in Styela plicata, whereas the level decreased to 1.55 from 1.62 in 5tyela clava.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.410-414
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• 2013

Styela (S.) clava (Korean name: miduduk) tunic is produced as a by-product after processing of S. clava. For utilizing this tunic, a konjac containing the tunic extracts was prepared and the qualities evaluated for their color, textural properties, and sensory attributes. The tunic extract was prepared by boiling tunic with water, followed by filtration through filter paper. Significant 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity was found in the tunic extract. Increasing the concentration of tunic extract in the konjac tended to decrease lightness (L) and increase the redness (a) and the yellowness (b) of the konjac. The strength and hardness of the konjac increased with increasing concentrations of the tunic extract. All test samples with a 3 mm thickness had good flexibility and did not break even after 4 times folds. In sensory evaluations, the konjac containing 25% S. clava tunic extracts acquired a relatively higher score. The results suggest that S. clava tunic can be applied to konjac products to improve their quality and functionality.