Min Soo Heu

Molecular characteristics and anti-inflammatory activity of the fucoidan extracted from Ecklonia cava

Enzymatic extraction has been successfully used for extracting numerous biologically active compounds from a wide variety of seaweeds. In this study, we found that enzymatic extraction of the fucoidan from Ecklonia cava may be more advantageous than water extraction. Therefore, we studied the E. cava fucoidans extracted by the enzymatic extraction technique and used ion-exchange chromatography to determine their molecular characteristics and anti-inflammatory activities. The crude and fractionated fucoidans (F1, F2, and F3) consisted mostly of carbohydrates (47.1-57.1%), uronic acids (9.0-15.8%), and sulfates (16.5-39.1%), as well as varying levels of proteins (1.3-8.7%). The monosaccharide levels significantly differed, and the composition included fucose (53.1-77.9%) and galactose (10.1-32.8%), with a small amount of rhamnose (2.3-4.5%), xylose (4.0-8.2%), and glucose (0.8-2.2%). These fucoidans contained one or two subfractions with an average molecular weight (Mw) ranging from 18 to 359×10(3)g/mol. These fucoidans significantly inhibited NO production in lipopolysaccharide (LPS)-induced Raw 264.7 macrophage cells by down-regulating the expression of iNOS, COX-2, and pro-inflammatory cytokines such as TNF-α, IL-6, and IL-1β. Thus, the present results suggest that E. cava fucoidan may be a potentially useful therapeutic approach for various inflammatory diseases.

Neuroprotective effects of phlorotannins isolated from a brown alga, Ecklonia cava, against H2O2-induced oxidative stress in murine hippocampal HT22 cells.

Exposure of neurons to hydrogen peroxide (H(2)O(2)) results in oxidative stress and the activation of a cascade of intracellular toxic events resulting in oxidation, lipid peroxidation, and Ca(2+) elevation, ultimately resulting in cell death. In this study, we attempted to characterize the neuroprotective effects of phlorotannins isolated from Ecklonia cava, including phloroglucinol, eckol, triphloroethol A, eckstolonol, and dieckol, against H(2)O(2)-induced cell damage in murine hippocampus neuronal (HT22) cells. We measured the reactive oxygen species (ROS) and lipid peroxidation levels and evaluated the resultant cell death and alterations in Ca(2+)-concentrations. All phlorotannins were to scavenge intracellular ROS and repress ROS accumulation, thus preventing lipid peroxidation. Consquently, all phlorotannins reduced H(2)O(2)-induced cell death in HT22 cells. Moreover, phlorotannins inhibited H(2)O(2)-induced Ca(2+) release. This study provides a new useful strategy for preventing neuronal H(2)O(2)-induced oxidative stress.

Improvement on Fish Odor of Extracts from Salmon Frame Soaked in Soybean Milk

For the use of extracts from salmon frame as a basic material of Gomtang-like products, various methods (soaking into soybean milk, adding anchovy, and adding spices) for masking fish odor into extracts from salmon frame were examined and the food component characteristics were also compared with commercial Gomtang. According to the results of volatile basic nitrogen, transmission at 660 ㎚ and sensory evaluation of extracts, soaking treatment, which is the soaking of salmon frame into soybean milk, was the most efficient method among the various methods for masking fish odor into extracts from salmon frame. There was no difference in the proximate composition between extracts from salmon frame soaked (FS) and unsoaked (C) into soybean milk. The FS was not detected in heavy metals, such as chromium, lead and cadmium. The taste value of FS (16.26) was higher than that of C and the major amino acids were glutamic acid and aspartic acid. Total amino acid content of FS (3.08 g/100 mL) was also higher than those of C (2.95 g/100 mL) and commercial Gomtang (1.70 g/100 mL), and the major amino acids were glycine, proline, glutamic acid and arginine. The calcium and phosphorus contents of FS/500 mL accounted for 21.7% and 18.5%, respectively, of the recommended daily allowance of mineral for adult.

[P3-10] Preparation of Accelerated Salt-fermented Anchovy Sauce Added with Shrimp Byproducts

The purpose of this study was to prepare accelerated salt-fermented anchovy sauce using a shrimp processing byproducts (head, shell and tail) as a fermenting accelerator, and to investigate its physicochemical and enzymatic properties. Four types of sauces were prepared with 0, 10, 20, and 30 (w/w) addition of shrimp byproduct and fermented at 242 for 360 days. During fermentation, all four type sauces decreased moisture content (67.568.0 to 64.064.8) and pH (5.527.10 to 5.036.58), but showed increase in their crude protein (7.08.2 to 10.8) and volatile basic nitrogen contents (4075 to 180200 mg/100 g of sauce). The ratio of amino nitrogen to total nitrogen contents of control (0) and sauce with 10 shrimp byproducts (10 sauce) were maximized at 270 days, whereas 20 and 30 added sauces were at 180 days. Endoprotease and exoprotease activities of anchovy sauces added with 20 and 30 of shrimp byproducts tend to be higher than those of control (0) and 10 addition. Proteolytic activities of sauces at pH 9 were about 2 times higher than those at pH 6. Amidolytic activities for LeuPNA decreased remarkably during fermentation, and control (0) almost lost their activity at 180 days, while additional sauces were relatively stable. These suggest that alkaline pretense of anchovy and shrimp byproducts as a endoprotease mainly contributed to the fermentation of salt-fermented sauces. The protein molecular weight distribution of sauces indicated 2 groups of peaks (peak 1,>70,000 da and peak 2, 3,00029,000 da). As the fermentation proceeded, peak 1 tended to decrease in all of sauces, but peak 2 increased rapidly from 30 to 270 days. Optimum fermentation periods of control and 10 sauces were 270 days and those of 20 and 30 sauce were 180 days. The results suggest that shrimp byproduct can be used as accelerator of salt-fermented sauce.

Fractionation and Characterization of Protease Inhibitors from Fish Eggs Based on Protein Solubility

A protease inhibitor was fractionated from fish eggs using methods based on protein solubility. Fractionation efficiency was evaluated with regard to percent recovery and total inhibitory activity (U). The fractionation of protease inhibitor(P1) from egg extracts of skipjack tuna (ST, Katsuwonus pelamis), yellowfin tuna (YT, Thunnus albacores), and Alaska pollock (AP, Theragra chalcogramma) was performed by precipitation with cold acetone or ammonium sulfate (AS). Fractions exhibiting the strongest inhibitory activity contained 20-40% (v/v) cold acetone or 40-60% saturated AS fractions. AS fractionation was more effective in isolating Pt than was precipitation with acetone. The total inhibitory activity and percent recovery of fraction obtained with AS 40-60% toward tlypsin and Na-benzoyl-Larginine-p-nitroanilide(RAPNA)were4,976 Uand 24,2% for ST. 3,331 U and 38.1% for YT. and 4,750 U and 43.8% for AP, respectively. In comparisons against six commercial proteases, 40-80% AS fractions, made by combining the 40-60% and 60-80% AS fractions from fish egg extract, exhibited the strongest inhibition of trypsin when using a casein substrate. These results suggest that fish eggs act as serine protease inhibitors and may be useful for protease inhibition in foodstuffs.

Comparison of collagen characteristics of sea- and freshwater-rainbow trout skin

Proximate composition, volatile basic nitrogen content, and concentrations of collagen in skin samples from either sea- (S-RT) or freshwater-rainbow trout (F-RT) were characterized and compared, to assess the effect of the sea or freshwater habitat on these parameters. Results of amino acid composition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, thermal denaturation assay and Fourier transform infrared (FT-IR) spectroscopy of acid-soluble collagens were comparable between the two sample sets. Both acid-soluble collagens from sea- and freshwater-rainbow trout skins contained glycine as the major amino acid and high alanine, proline, and hydroxyproline contents, and was found to be predominantly composed of α1-, α2-, and β-chains. FT-IR spectra of ASCs from S-RT and F-RT skins were quite similar. These findings suggest that different rainbow trout habitats (seawater and freshwater) do not affect amino acid composition and molecular weight properties of ASCs from S-RT and F-RT skins.

Sensory Characterization of Domestic Mottled Skate Raja pulchra as Affected by Area Caught, Sex and Fish Weight

This study investigated the food quality characteristics of mottled skate Raja pulchra including the proximate composition, taste, color, flavor and texture as affected by area caught (Heuksando and Daecheongdo), sex and fish weight (heavy, intermediate and light grades). Based on viable cell counts, all of the mottled skates studied remained fresh. The moisture and protein contents of the mottled skate did not differ by the area caught and fish weight, but differed by fish sex. The taste of mottled skate was affected only by fish weight. The texture of the mottled skate differed according to fish sex and fish weight. The odor intensity did not differ for the three parameters.

Risk Assessment of Oyster Crassostrea gigas Processing Site For an HACCP System Model

최근 우리나라 양식산 굴은 연간 생산량이 약 30만톤 내외에 이르고 있고, 국내 패류 총 생산량의 60% 이상을 차지하여 우리 나라의 주요 양식 자원이다(Ministry of Oceans and Fisheries, 2016). 굴은 칼슘, 철분 등과 같은 조혈성분이 풍부하여 어린이 발육과 허약 체질 개선에 좋고, 저칼로리 식품으로 비만을 막아 주며, 글리코겐 및 타우린이 많아 심장병, 고혈압, 변비, 당뇨병 등을 예방하는 기능이 있어 영양 및 건강 기능성이 우수한 식품 중의 하나이다(Linehan et al., 1999; Hosoi et al., 2003; Kim et al., 1981; Sakaguchi and Murat, 1989). 일반적으로 굴의 소비 형태는 비산란기인 11월부터 4월까지의 경우 고가의 생굴로, 그리고 산란기이어서 생굴로 식용이 곤란하거나 저가인 5월부 터의 경우 주로 냉동품, 건제품 및 통조림 등으로 가공되어 수출 되고 있다(Kim et al., 2002). 그러나 최근 양식산 굴은 내수를 목적으로 한 생굴 비중이 점차 증가하고 있고, 이들은 대부분이 탈각 후 유통되고 있다(Park et al., 2006). 굴 양식장이 위치하고 있는 우리나라 연안은 최근 경제성장에 따른 인구 밀집과 강우 발생으로 일반세균 농도는 물론이고, 장 관계 바이러스 등의 식중독 원인체가 함유될 가능성이 있는 분 변성 오염물질의 농도가 증가하고 있다. 따라서, 이와 같이 오 염된 해역에서 생산된 굴은 자연히 식중독의 원인물질을 함유 할 가능성이 크다(Lee et al., 2010; Oh et al., 2012; Iritani et al., 2014). 또한, 굴 탈각장은 FDA나 EU 등록공장을 제외하고 는 관련법규나 전처리 가공공장 관리 규정이 미흡한 위생관리 의 사각지대에 놓여 있다. 이러한 측면에서 생굴의 안전성을 확 보하기 위한 방안은 굴 탈각장에 HACCP (hazard analysis and critical control point) system을 도입하여 생굴에 대한 기준 규 HACCP 구축을 위한 굴(Crassostrea gigas) 가공공장의 위해 평가 강경태·김민주·박선영·최종덕·허민수·김진수*

A Comparison of the Taste and Nutritional Properties of Domestic Mottled Skate Beringraja pulchra according to the Area Caught, Sex, and Weight

This study investigated the taste and nutritional properties of domestic mottled skate Beringraja pulchra as affected by the area caught, sex, and weight. Regardless of these three parameters, free amino acids comprised the main factor affecting taste in all B. pulchras. Taste values for B. pulchra ranged from 2.24 to 3.61, which were much lower than values for other fish. The total amino acid content in B. pulchra ranged from 18.82 to 21.34 g/100 g, similar to values in other fish. The major amino acids affecting both the taste value and total amino acid in B. pulchra were glutamic acid, aspartic acid, and lysine. Mineral content in B. pulchra was as follows: calcium, 252.7-288.3 mg/100 g; phosphorus, 248.2-269.3 mg/100 g; potassium, 345.9-389.5 mg/100 g; magnesium, 24.1-26.7 mg/100 g; and iron, 0.4-0.7 mg/100 g. Based on the results of free amino acid and taste value (used as an indicator to evaluate taste), and total amino acid and minerals (used as an indicator to evaluate nutritional value), the taste and nutritional properties of B. pulchra were not influenced by the area caught or weight, but were affected by the sex of the fish.

Chromatographic Fractionation of Protease Inhibitors from Fish Eggs

A protease inhibitor from fish eggs was fractionated using chromatographic methods. The fractionation efficiency was evaluated in terms of specific inhibitory activity (SIA, U/mg), purity (fold), total inhibitory activity (TIA, U), and recovery (%). The protease inhibitor (PI) from egg extracts of skipjack tuna (ST Katsuwonus pelamis), yellowfin tuna (YT Thunnus albacares) and Alaska pollock (AP Theragra chalcogramma) was fractionated using Sephadex G-50 gel filtration and DEAE-Sepharose CL-6B anion exchange chromatography based on protein size exclusion and net charge, respectively. Fractions exhibiting strong inhibitory activity were contained in the 30-50 kDa fraction on gel filtration and in the range of 0.4-0.7 M NaCl gradient fraction on anion exchange chromatography. The respective TIA and percent recovery of the fraction obtained with gel filtration toward trypsin and -benzoyl-L-arginine-p-nitroanilide (BAPNA) were 2,758.7 U and 29.6% for ST, 1,005.5 U and 25.6% for YT, and 1,267.5 U and 26.0% for AP. Gel filtration chromatography was more effective at fractionating PI than using ion exchange chromatography. These results suggest that fish eggs act as serine protease inhibitors and might be useful for protease inhibition in foodstuffs.