• Mass Spectrometry Letters
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• 제9권4호
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• pp.100-104
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• 2018

As a part of efforts to establish the positive list system (PLS) in South Korea, a method to determine residual emamectin benzoate (EB) in various aquatic products using QuEChERS-EDTA and LC-MRM was developed. The developed method was validated in the aspects of specificity, linearity (correlation coefficient of at least 0.996), sensitivity (the limit of detection and the lower limit of quantitation ${\leq}5ng/g$), recovery (the recovery range of 87.4 and 96.2), and precision (the relative standard deviation of recovery between 0.9 and 13.5). Additionally, the validated method was successfully applied for monitoring EB contamination in eel, halibut, and shrimp collected from local food markets. To our knowledge, the present method is the first one to determine residual EB in various aquatic products at the level satisfying the PLS and could contribute to the establishment of the PLS in South Korea.

• Mass Spectrometry Letters
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• 제12권1호
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• pp.11-15
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• 2021

Nitarsone is an organoarsenic antiprotozoal drug widely used to treat blackhead disease in turkeys and chickens. However, since its biological conversion into inorganic arsenic, a carcinogen was known, its residue in foods should be regulated. Thus, here, a novel method to determine residual nitarsone in various food commodities (pork, milk, egg, halibut, eel, and shrimp) using QuEChERS and LC-MRM was developed. The developed method was successfully validated through specificity, linearity (coefficient of determination, at least 0.991), recovery (R, 63.6 - 85.6%), precision (the relative standard deviation of R, 0.5 - 10.6%), and sensitivity (the lower limit of quantitation, 5 ppb) by following the Ministry of food and drug safety (MFDS) guidelines. The present method is the first mean to quantitate nitarsone using LC-MRM, and it was designed to be conveniently merged into a new method to quantitate multiple veterinary drugs for the positive list system (PLS). Therefore, the present method could contribute to fortify the food safety system in South Korea.

• 한국수산과학회지
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• 제51권3호
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• pp.230-237
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• 2018

This study investigated the food and nutritional characteristics of alkaline-insoluble fractions (AIFs) recovered from bastard halibut Paralichthys olivaceus (BH) and skipjack tuna Katsuwonus pelamis (ST) roes using the alkaline solubilization. The moisture content of AIFs ranged from 4.8% to 12.8%, and ST provided significantly better yields (9.5 for STAIF-11 and 7.1 g/100 g roe for STAIF-12) than did BH (P<0.05). The protein content of AIFs ranged from 71.7% to 79.2%, with the highest level yielded by STAIF-11 (6.8 g/100 g roe). The crude fat content of AIFs was 10.9-14.3% and the mineral content was 0.7-3.4%. The major mineral components of AIFs were sulfur, sodium, potassium, and phosphorus. Color values showed that BHAIFs were significantly brighter than STAIFs. Total contents of essential amino acids were significantly higher in STAIFs (47.5-49.5%) than in BHAIFs. The major essential amino acids found in AIFs from both sources were Val, Leu, Lys, and Arg. Therefore, AIFs were significantly superior to whole BH roe in terms of physicochemical and nutritional status, and we identified species-specific differences between BH and ST. Protein is a major component of AIFs recovered from fish roes, which suggests that they have potential for use as a protein source.

• 한국수산과학회지
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• 제53권2호
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• pp.165-173
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• 2020

Fish roe is among the most valuable food resources produced by fisheries. Raw fish roe requires processing for conversion into hygienic, marketable, and consumer-acceptable forms. In this study, to investigate the food compositional characteristics of various types of fish roe, we applied vacuum freeze-drying to prepare fish roe concentrates (FRCs) from roe of Alaska pollack Theragra chlcogramma, bastard halibut Paralichythys olivaceus, and skipjack tuna Katsuwonus pelamis. The FRC yield ranged from 22.7 to 26.7 g/100 g roe. The major constituents of FRCs were protein (65.4-79.6%), moisture (2.8-6.2%), lipids (8.5-18.3%), and ash (4.8-7.2%). Potassium, sulfur, sodium, and phosphorus were the major mineral elements of FRCs, and the major amino acids were aspartic acid (9.0-10.4 g/100 g protein), glutamic acid (13.2-14.5 g/100 g protein), lysine (8.4-8.6 g/100 g protein), and leucine (8.3-9.7 g/100 g protein). Vacuum freeze-dried FRCs differed among fish species in terms of amino acid composition and electrophoresis protein band distribution. Therefore, FRCs are an excellent source of protein nutrition and an appropriate protein fortification material in human foods or animal feed.

• Applied Microscopy
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• 제32권2호
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• pp.121-129
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• 2002

넙치의 피부 상피층은 지지세포, 선세포와 부속세포들로 구성된다. 지지세포는 표면세포, 중간세포 및 기저세포로 구분된다. 선세포는 점액세포와 곤봉상세포, 부속세포는 염세포가 관찰된다. 표면세포는 편평형 또는 입방형이며 미융기들이 잘 발달되어 있다. 지지세포는 menbrane interdigitation구조와 부착반에 의해서 다른 세포들과 잘 연결되어 있고 세포질 피질부에 당김세사가 잘 발달되어 있다. 점액세포는 타원형으로 중성다당류의 점액을 함유하는 것으로 확인된다. 곤봉상세포는 세포질에 많은 액포와 미세섬유다발을 관찰할 수 있다. 부속세포인 염세포 세포질의 대부분이 미토콘드리아로 가득 채워져 있다.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.8-11
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• 1999

The optimum boiling condition was determined for fish extracts by response surface model. Model equations were designed with effect of time (T) and the amount of added water (W) on the level of released free amino acid. Based on the high (>0.9) coefficient of determination and low (<0.01) level of significant, those model was approved to be significant. The added water amount of higher regression coefficient $ (\beta_2)$, showed a greater influence on releasing free amino acids than boiling time. The optimum boiling times are 6 hours for crucian carp, 5 hours for bastard halibut, 7 hours for loach and 5 hours for jacopever. The ratio of added water to sample 1 (v/w) could be applied to all fish samples at $100\pm2^{\circ}C$.

• 한국식품영양과학회지
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• 제27권1호
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• pp.93-101
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• 1998

In order to improve the functional properties of several fish meat extracts as an alternate protein source, theri basic plastein reactions were evaluated. The UV absorption at 270 and 290 nm indicated that plasteins had higher amount of hydrophobic peptide or amino acid than the fish meat extracts. The water solubilities of the extracts were reduced at acidic pH. Values for the emulsifying capacity of the extracts and plasteins were over 30% although the latter showed the higher ones than the former. The osmolalities of the extracts at 1.0% concentration were 39(loach), 33(bastard halibut), 30(jacopever) and 24(crucan carp) milliosmole. Generally the slightly higher osmolalities were noted in the plasteins to be compared with the extracts. Both the extracts and plasteins exhibited a higher antioxidative effect than tocopherol. The hydrophobic amino acid which had been introduced at plastein reaction attributed the stronger antionxidative effect of its product than the extracts.

• 한국양식학회지
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• 제20권3호
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• pp.199-202
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• 2007

본 연구에서는 넙치(Paralichthys olivaceus) 정소로부터 DMRT-1 partial cDNA를 분리하였다. 넙치 DMRT-1은 317개의 염기로 구성되어 있으며, Atlantic halibut, 감성돔 및 무지개 송어와 각각 94%, 85%, 82%의 높은 상동성을 보였다. RT-PCR을 이용하여 DMRT-1 mRNA 발현은 난소보다 정소에서 높게 나타난 것을 관찰할 수 있었다. 또한, 암컷 넙치에 웅성호르몬인 testosterone 처리시 처리 농도에 따라 난소에서 DMRT-1 mRNA 발현이 증가함을 볼 수 있었다. 따라서, DMRT-1은 수컷에서 특이적으로 발현되는 유전자임을 알 수 있으며, 본 연구의 결과는 넙치의 성 전환 및 유도에 대한 기초자료를 제공할 것이다.

• 한국수산과학회지
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• 제50권6호
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• pp.694-706
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• 2017

This study evaluated the protein recovery, functional properties and biological activity of isolate processed water (IPW) generated in the preparation of protein isolates from fish roes (BH, bastard halibut Paralichthys olivaceus; ST, skipjack tuna Katsuwonus pelamis; YT, yellowfin tuna Thunnus albacares) by an isoelectric solubilization and precipitation process. The IPWs contained 2.7-5.4 mg/mL of protein, and the protein losses were 8-21% (P<0.05). The form capacity of IPW-3 for BH and ST, and IPW-4 for YT was 155, 194, and 164%, respectively. The emulsifying activity index ($27-43m^2/g$) of the YT-IPWs was the strongest, followed by ST ($7-29m^2/g$) and BH ($10-19m^2/g$). The 2,2-diphenyl-1-picrylhydrazyl scavenging activities of IPW-1 and -3 were higher than those of IPW-2 and -4. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid scavenging activity ($IC_{50}$, mg/mL) of IPW-2 and -4 was 0.03 mg/mL for BH, 0.04-0.08 mg/mL for ST, and 0.04-0.07 mg/mL for YT. BH IPW-3 had the strongest reducing power (0.41 mg/mL) and superoxide dismutase-like activity (1.68 mg/mL). The angiotensin-I converting enzyme inhibitory activity of IPW-3 was the highest for ST (1.52 mg/mL), followed by BH and YT. The common predominant amino acids in the IPWs were the essential amino acids Val, Leu, Lys, and Arg and the non-essential amino acids Ser, Glu, and Ala.

• Preventive Nutrition and Food Science
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• 제4권1호
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• pp.23-27
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• 1999

To evaluate the quality of fish extracts with spicy vegetables (garlic, onion and ginger) in suppressing fishy oder, fish extracts of crucian carp, loach, bastard halibut and jacopever were processed at 100 $^{\circ}C$ for 6 hours, and their in vitro and in vivo protein qualities were determined . Protein and total lipid contents were closely related to the degree of discarding floated lipid on fish extracts and the kinds of added apicy vegetables . Boiling (10$0^{\circ}C$) , appeared to improve in vitro protein qualities slightly more than hydrocooking (11$0^{\circ}C$), but those with mild processing tended to result in better protein qualities than high temperature cooking (136-14$0^{\circ}C$). Spicy vegetables did not have remarkable effects on improving in vitro protein quality parameters. Fish extracts with 10% ginger were generally higher in in vitro protein quality than with the other vegetables . In spite of higher in vivo protein digestibility of fish extracts containing spicy vegetables processed under mild conditions(10$0^{\circ}C$), PERs of those extracts were not higher htan those of extranct processed at high temperature.