• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.598-605
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• 2010

This study investigated the physicochemical and enzymatic properties of unmarketable bastard halibut (Paralichthys olivaceus) cultured in different regions (i.e., Jeju, Wando, and Geoje) as a potential source of surimi and surimi gel. The proximate composition of unmarketable bastard halibut cultured in different regions did not differ significantly at P<0.05. Compared to Alaska pollock muscle, all of the unmarketable bastard halibut muscle had a 4% higher crude protein content and 5% lower moisture content. The collagen content of bastard halibut muscle cultured in Jeju was 1.96 g/100 g, which was higher than in fish cultured in other regions. Regardless of the region where cultured or pH, the enzymatic activities of the crude extracts from unmarketable bastard halibut muscle ranged from 0.30.0.48 U/mg for casein and hemoglobin, 11.9.13.7 U/mg for LeuPNA, 5.6.6.7 U/mg for ArgPNA, 2.8.4.7 U/mg for SAAPFNA, and 0.1.0.2 U/mg for BAPNA. Regardless of region, no mercury or lead was found in any of the unmarketable bastard halibut muscle, except for lead in fish cultured in Geoje. The strength of surimi gels from unmarketable bastard halibut cultured in Jeju, Geoje, and Wando was 1059, 988, and 900 g${\times}$cm, respectively. The surimi gel from unmarketable bastard halibut cultured in Jeju was stronger than commercial Alaska pollock surimi, which was grade SA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.435-442
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• 2011

This study was conducted to optimize the processing of high quality surimi gel from unmarketable cultured bastard halibut Paralichthys olivaceus. According to endogenous enzyme activity and processing optimization, high quality surimi gel from unmarketable cultured bastard halibut was prepared by mixing 3.0% (w/w) salt, 2.4% (w/w) starch, 5.0% (w/w) egg white and 4.8% (w/w) ice water in a Stephan mixer, set at $5^{\circ}C$ for 24 h, followed by boiling for 30 min, and finally cooling for 30 min. The strength of the surimi gel from unmarketable cultured bastard halibut prepared by the above processing method was $1,257\;g{\times}cm$, which was 33% higher than that of a commercial surimi gel from Alaska pollock, grade SA.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.18-24
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• 2011

This study investigated the physicochemical and enzymatic properties of unmarketable cultured bastard halibut (Paralichthys olivaceus) of different weights as a potential source of surimi and surimi gel. The proximate composition of cultured bastard halibut of different weights did not differ significantly at P<0.05 (light weight (LBH) 400~500 g, medium weight (MBH) 600~800 g, and heavy weight (HBH) > 1,000 g). Compared to Alaska pollock muscle, the bastard halibut muscle had a 4% higher crude protein content and 6% lower moisture content. The collagen content of LBH bastard halibut muscle was 1.58 g/100 g, which was lower than or no different from bastard halibut weighing different amounts. Regardless of fish weight or pH, the enzymatic activities of crude fish extracts ranged from 0.34~0.48 U/mg for casein and hemoglobin, 11.0~12.7 U/mg for LeuPNA, 5.4~6.1 U/mg for ArgPNA, 2.3~2.9 U/mg for SAAPFNA, and 0.1~0.2 U/mg for BAPNA. The yield of surimi gel from LBH was 24.4%, which was similar to that from MBH and lower than that from HBH. The surimi gel from LBH was similar to that from HBH, while weaker than that from MBH. The surimi gel from LBH gel was stronger than grade SA gel from commercial Alaska pollock.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.191-196
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• 2011

In this study, we investigated the chemical and enzymatic properties of unmarketable cultured bastard halibut (UCBH) Paralichthys olivaceus harvested at different times (March, May, July, September, November, and January), and we examined the physical properties of surimi gel from UCBH as a potential source of surimi and surimi gel. The moisture and crude protein contents of UCBH harvested in July and January were >78% and <19%, respectively, which is greater than the moisture content in UCBH harvested in May, March, and September, but lower than the crude protein content. Regardless of the month of harvest, the UCBH had a higher crude protein content than Alaska pollock, which is the largest fishery biomass used for surimi and surimi gel, but a lower moisture content. Regardless of the month of harvest, the enzymatic activity in crude extracts of UCBH muscle ranged from 0.31-0.59 U/mg for casein (pH 6.0 and 9.0) and 11.7-12.7 U/mg for LeuPNA. These findings suggest that autolytic enzymes were unaffected by gel formation. Gel strength was highest in the surimi gel prepared from UCBH harvested in September, November, and January; second highest in that prepared from UCBH harvested in March and May; and lowest in that prepared from UCBH harvested in July. Compared to the gel strength of surimi gel from grade SA commercial Alaska pollock surimi, the strength of the surimi gels prepared from UCBH harvested in March, May, September, November, and January were superior, whereas that of the surimi gel prepared from UCBH harvested in July was similar.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.178-186
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• 2015

Protease inhibitors (PI) of trypsin and papain as target proteases from the roe of bastard halibut Paralichthys olivaceus were fractionated out using ammonium sulfate precipitation (A), DEAE 650M anion exchange chromatography (D), and Sephacryl S-300 gel filtration (S). The recovery percentages of the fractions with the strongest inhibitory activity for each fractionation method were 13% for the A4 fraction, 21.2% for the D3 fraction, and 21.3% for the S2 fraction, with specific inhibitory activities of the fractions toward trypsin and casein of 168, 139, and 218 U/mg, respectively, while no inhibition of papain was observed. The $IC_{50}$ for the trypsin-specific substrate $N{\alpha}$-benzoyl-$\small{L}$-arginine-p-nitroanilide (BAPNA) was 0.65, 1.55, 2.26, and 2.85 mg/mL for the A4, S2, A3, and D3 fractions, respectively. These results suggest that chromatographic fractionation methods (D and S) based on the molecular mass and charge of the protein were more effective at fractionating PI than was ammonium sulfate precipitation based on protein solubility, and that the bastard halibut roe extract acts as a serine protease inhibitor. Therefore, the PI fraction from fish roe might be useful for inhibiting proteases in foodstuffs, and could constitute an alternative food-grade inhibitor for the surimi industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.351-361
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• 2018

This study investigated the potential of collagenous protein fractions (CPFs) as functional foods. The specific CPFs studied were recovered from the roe of bastard halibut (BH), Paralichthys olivaceus; skipjack tuna (ST), Katsuwonus pelamis; and yellowfin tuna (YT), Thunnus albacares through the alkaline solubilization process at pH 11 and 12. The buffer capacity, water-holding capacity and solubility of CPFs with pH-shift treatment were significantly better at alkaline pH (10-12) than at acidic pH (2.0). At pH-shift treatment (pH 2 and 12), the foaming capacities of CPFs from ST and YT were improved compared to those of controls, but they were unstable compared to BH CPFs. The emulsifying activity index (EAI, $m^2/g$ protein) of CPFs (controls) was 16.0-21.1 for BH, 20.1-23.9 for ST and 9.3-13.7 for YT (P<0.05). CPFs adjusted to pH 12 showed improved EAI and YT CPFs showed significantly greater emulsifying ability than those from BH and ST. CPFs recovered from fish roe are not only protein sources but also have a wide range of food functionalities, confirming the high availability of fish sausage and surimi-based products as protein or reinforcing materials for functional foods and alternative raw materials.

• Journal of Life Science
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• v.25 no.11
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• pp.1280-1289
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• 2015

Fish-meat gel is being produced mostly relying on surimi and raw materials imported from Southeast Asia and North America and present in small amount in local markets. In this study, common farmed local fishes were examined as stable and reliable sources of surimi for fish-meat gel production. For testing, five main farmed-fish of Korea, namely; Bastard halibut (Paralichthys olivaceus), Red sea bream (Pagrus major), Korean rockfish (Sebastes schlegeli), Common mulle (Mugil cephalus), and Finespotted flounder (Pleuronichthys cornutus) were used following a traditional washing process. The quality of the surimi was determined by the values of water content, whiteness index, gel strength and impurity. Accordingly, fish-meat gel and surimi quality experiments were carried out by measuring compressive and texture properties, expressible moisture content, Hunter color scale values and SDS-page protein patterns. Also gel characteristics were compared with that of FA and RA grade surimi (Alaska Pollock). Fish-meat gels were prepared by salt mincing the farmed-fish surimi with NaCl (2% w/w) and moisture adjustment to 84% by ice water adding. Prepared fish-meat paste was filled into 20-25 cm long polyvinylidene chloride casings and heated at 90℃ for 20 min. The whiteness values of fish-meat gels produced from surimi were increased by using farmed-fish and became comparable to that of FA Alaska Pollock gel. Among all tested farmed-fish, P. olivaceus and P. major exhibited better properties than RA Alaska Pollock and similar properties to FA Alaska Pollock. Therefore, current data suggests that fish farming can be an efficient and sustainable fish-meat source for fish-meat gel production in Korea.