Ho Dong Yoon

Organic Acid Extraction of Fluoride from Antarctic Krill Euphausia superba

The amount of fluoride removed from Antarctic krill via organic acid extraction depends on the extraction time, concentration, extraction volume, and the nature of the acid itself. The fluoride content in Euphausia superba was determined by measuring the concentration of fluoride ion in acidic extracts using an ion-selective electrode. The best results were obtained by adding 50 mL of 0.01 M citric acid to 0.3-0.5 g of krill and extracting for 5 min. Under these conditions, recoveries of fluoride from frozen whole krill and krill meat were 95.6-99.5% and 97.5-101.3%, respectively. The dry basis fluoride contents of krill by-product, krill meat and the boiled krill were 705, 298, and 575 ppm, respectively. These levels were significantly reduced by citric acid extraction.

Bioaccumulation of Heavy Metals in the Mussel Mytilus galloprovincialis in the Changseon area, Korea, and Assessment of Potential Risk to Human Health

From 2008 to 2013, the mussel Mytilus galloprovincialis were collected from a major area of mussel production (Changseon area), which is a designated shellfish-cultivating area for export, located on the southern coast of Korea. The samples were analyzed for mercury (Hg) using a direct Hg analyzer and for other metals, such as cadmium (Cd), lead (Pb), arsenic (As), chromium, copper, nickel, and zinc, using inductively coupled plasma mass spectrometry. The concentrations and bioaccumulation of the heavy met- als were determined, and a potential risk assessment was conducted to evaluate their hazards towards human consumption. The concentration and bioaccumulation ratio of Cd were the highest of the three hazardous metals (Cd, Pb, and Hg). The concentrations of hazardous metals in all samples were within the limits set by Korea and other countries. The estimated dietary intake (EDI) was compared to the provisional tolerable daily intake (PTDI) adopted by the Joint FAO/WHO Expert Committee on Food Additives and the U.S. Environmental Protection Agency. The EDIs of all heavy metals tested for mussel samples ranged from 0.01 to 4.99% of the PTDI; the highest value was measured for As. The hazard index (HI) can be used to assess the risk of heavy metal consump- tion associated with contaminated food. The HI for all samples was far less than 1.0, which indicates that the mussels produced in the Changseon area do not represent an appreciable hazard to humans and are fit for consumption.

Effects of Low Temperature and Starvation on the Physicochemical Characteristics of Muscle of the Olive Flounder Paralichthys olivaceus

The effects of low temperature and starvation on the physiochemical characteristics of the muscle of the olive flounder Paralichthys olivaceus, were examined. Fish were deprived of feed for 28 days at 2, 4, 6, 8, 10, 12, and in order to establish suitable conditions for live fish transportation. Throughout most of the 4 weeks of feed restriction, the physiochemical characteristics of the muscle of olive flounder were found to be dependent on the acclimation temperature. The breaking strength of muscle did not show a significant reduction during feed restriction at 2 and . With increasing temperatures, however, the breaking strength of muscle differed significantly according to the individual and feed restriction period (P increased steadily over the feed-restriction period, while the crude lipid content decreased during the same period (P, no significant differences were shown during the same period. After it reached 6, 8, 10, 12, and , the muscle had an accumulation of lactate, and a loss of ATP. There was no change in the lactate or ATP content during the feed restriction period at 2 and , although there were differences among the water temperature groups. These results clearly show that temperature can have an important influence on the of muscle of physiochemical characteristics of muscle during live fish transportation.

The Effect of Mushroom Extract as a Dietary Additive on the Nutritive Quality of Cultured Olive Flounder Paralichthys olivaceus

This study investigated the nutritive quality of olive flounder Paralichthys olivaceus fed either moist pellet (MP) or moist pellet mixed with mushroom extract (MPME) for 6 months. There was no significant difference in crude protein or extractive nitrogen in the muscle of flounder fed MP versus MPME (P > 0.05). The total amino acid content in the muscle of flounder fed MP was g/100 g, compared to g/100 g for flounder fed MPME. Essential amino acid content was g/100 g in the muscle of flounder fed MP versus g/100 g for MPME. Total amino acid content was higher in the muscle of olive flounder fed MPME, while essential amino acid content was higher in flounder fed MP. The ratio of non-essential amino acids to essential amino acids was for flounder fed MP and for flounder fed MPME. There was no significant difference in free amino acid content and fatty acid composition. The breaking strength of muscle of olive flounder fed MP was higher () than in flounder fed MPME (). There was no evidence that dietary additives, such as mushroom extract, increase growth rate or nutritive quality of olive flounder.

Nutritional Value and Bioactive Properties of Enzymatic Hydrolysates prepared from the Livers of Oncorhynchus keta and Oncorhynchus gorbuscha (Pacific Salmon)

Calculated chemical scores (computed in relation to the FAO/WHO reference protein) for salmon liver protein hydrolysates indicated that all amino acids (other than methionine and threonine) were present in adequate or excess quantities; thus, the raw liver material is a good source of essential amino acids. The hydrophobic amino acids contents in hydrolysates prepared from On- corhynchus keta and O. gorbuscha were 38.4 and 39.1%, respectively. The proportion of released peptides exceeding 500 kDa was reduced when hydrolysates were treated with the commercial enzyme Alcalase, although proportions in the following MW ranges were elevated: 100-500 kDa and <50 kDa. The optimal conditions for enzymatic hydrolysis were as follows: pH 7.0, 50°C, and a reaction time of 1 h. Of the different proteases tested, Alcalase was the most efficient for production of salmon liver hydrolysate with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity. The hydrolysates prepared from salmon liver had a balanced amino acid composition. The liver protein hydrolysates contained low molecular weight peptides, some of which may be bio-active; this bio-active potential should be investigated. Inhibition of the DPPH radical increased with increased degree of hydrolysis (DH), regardless of protease type. DPPH radical scavenging abilities, antithrombotic effects and α-glucosidase enzyme inhibition effects of O. keta liver hydrolysate increased in a dose-dependent manner. Thus, salmon liver hydrolysate may be useful in functional food applications and as a source of novel products.

Effect of Transport Stocking Density on the Physicochemical Characteristics of Muscle from Olive Flounder Paralichthys olivaceus

우리나라 양식산 넙치(Paralichthys olivaceus)의의 생산량은 연간 2013년 36,944톤이며, 전체 양식산 어류 생산량인 73,065 톤의 50.6%를 차지하고 있다. 그 중 활어로 수출되는 물량은 2011년 4,267톤, 2013년에는 3,370톤으로 다소 감소하였다. 양 식산 넙치는 대부분은 일본으로 수출되며, 그 수출량은 2011년 4,126톤, 2013년에는 2,967톤에 이른다. 일본 외에는 중국과 미 국에 수출되고 있으며, 특히 미국 수출량은 2011년 141톤에서 2013년 345톤으로 약 1.4배 증가하였다(MOF, 2014). 최근 양 식산 활넙치의 총 수출량은 다소 감소했지만, 미국으로의 수출 량은 점차 증가하고 있다. 이처럼 우니나라 양식산 넙치는 수출 물량 감소와 국내 소비량 정체로 과잉 공급되고 있는 실정이다 (Shim et al., 2012; Hwang et al., 2008). 과잉생산물량 해소를 위해서는 보다 적극적인 소비시장 개척이 필요하며, 그 대상국 가는 미국, 유럽 등으로 다양화할 필요가 있다. 해외 소비시장 확대를 위해서는 활어상태의 넙치를 안정적인 공급하여 가격 경쟁력을 갖추어야 하며, 이를 위해서는 대량 수송과 물류비용 이 저렴한 선박을 이용한 해상수송이 필요하지만 긴 수송시간 으로 인하여 수송과정에서 폐사를 최소화시켜야만 한다(Shim et al., 2012). 해상장거리 대량수송장치는 활어의 양식산 넙치를 저온 및 절식에 의하여 대사활동을 최소화하여 수송하는 원리이다. 이 러한 시스템은 생물을 수송하기 때문에 반드시 수조내에 해수 를 넣어 생물을 운송하게 된다. 따라서 수온은 활어 수송에 매 우 중요한 인자이다. 낮은 수온은 해수 중 pH 유지와 활어의 대사활동을 감소시킨다. 일반적으로 여름철 냉수성 어종의 최 적 수송 수온은 6-8°C이며, 온수성 어종은 10-12°C이다. 봄과 가을철은 각각 3-5°C과 5-6°C, 겨울철은 1-2°C로 알려져 있다 (Berka, 1986). 컨테이너 내부에 수조, 냉각기, 산소발생기, 여 과장치, 전기장치 등을 갖추고 있어 수송 중 온도와 산소를 일정 하게 조절하고, 생물의 대사활동으로 발생하는 대사산물을 여 수송밀도가 넙치(Paralichthys olivaceus) 근육의 물리화학적 변화에 미치는 영향 심길보*·윤호동

Effects of Krill Euphausia superba Fluoride Extract on Toxicity and Oxidative Stress in Liver cell

In this study, we investigated about cell toxicity and oxidative stress of HepG2 cell by treatment of sodium fluoride (NaF) and fluoride extracts from krill Euphausia superba meat, shell, whole body and krill meal. The cell toxicity showed significant at 300 and

Accumulation and Depletion of Melamine Through Experimental Feeding in Catfish Silurus asotus

500{\mu}g/mL

Biochemical characterization of collagen from the starfish Asterias amurensis

NaF treatment group....

Mineral Content and Nutritional Evaluation of Marine Invertebrates from the Korean Coast

In 2007, pet food contaminated with melamine caused hundreds of dogs and cats to develop renal failure all over the world. In 2008, over 294,000 infants consumed infant formula and developed kidney stones in China. Further investigation revealed that fish feed also contained melamine; this raised concerns about melamine residues in edible fish tissues, which could have caused the urinary tract stone epidemic. In Korea, catfish fed with assorted feed that included cuttlefish organs that contained melamine developed whitening syndrome and fell dead in some populations in 2008. This event raised suspicions about the toxicity of melamine and all feeds containing melamine were immedi-ately recalled. In this study, we investigated the rates of melamine accumulation and depletion in muscle and viscera of catfish to propose proper withdrawal periods. One group of catfish was fed a commercially available diet that con-tained 30, 100 and 300 mg melamine per kg diet for 14 days. To investigate residual melamine contents in muscle and viscera, other experimental groups were fed a melamine free diet after being fed melamine for 7 days. The residual amount of melamine was analyzed by LC-MS/MS. The melamine concentration in muscle was estimated to be 3.7 mg/kg after 6 days of feeding with a diet containing 300 mg melamine/kg. After 2 days of culture with a melamine free diet, the residual melamine was depleted and the concentration had decreased from 1.15 mg/kg to 0.19 mg/kg in the muscle of catfish fed a diet containing 300 mg melamine/kg for 7 days. The residual amount of melamine was reduced to 0.03 mg/kg in muscle after 7 days of culture with a melamine free diet and was undetectable after a pro-longed culture period of 14 days. Catfish tend to excrete melamine rapidly after oral administration and changes in body color were not observed during the short dosing period. Key words: Melamine, Catfish, LC-MS/MS