Collagen peptides have garnered significant attention as functional foods across multiple fields due to their capacity to regulate physiological and hormonal processes, offering numerous advantages. However, despite their broad range of applications, comprehensive research on the potential toxicity of these substances remains lacking. Therefore, this study sought to assess the acute oral toxicity of a collagen peptide derived from skate (Raja kenojei) skin (CPSS) in both rats and dogs. In the rat model, CPSS was orally administered at doses of 300 and 2,000 mg/kg to Sprague-Dawley rats. An escalating single-dose oral toxicity assessment at doses of 500, 1,000, and 2,000 mg/kg was carried out in beagle dogs with 3-day intervals between doses. Throughout the 14-day post-administration assessment period, clinical signs, mortality rates, changes in body weight, and necropsy observations were closely monitored. After oral administration, no signs of toxicity associated with CPSS were observed in either rats or dogs. Therefore, the oral LD50 (approximate lethal dose for 50% mortality) for CPSS in rats was determined to exceed 5,000 mg/kg, and the maximum tolerated dose for dogs was estimated to be above 2,000 mg/kg. Consequently, this study offers safety data on the use of CPSS in functional foods and medicinal applications.

본 연구의 목적은 PAPS-D를 활용하여 인라인스케이트 프로그램이 발달장애 학생들의 건강 체력 향상에 미치는 효과를 알아보는 것이다. 대상자는 발달장애 판정을 받은 중고등부 학생 10명으로 구성 되었고 16주 동안 주2회 총32회 수업을 하였으며, 수업시간은 매 시간 60분으로 하였다. 건강 체력 향상을 측정하기 위한 검사 도구는 2016학년도 교육과학부에서 개발한 PAPS-D 프로그램으로서 비만도 측정을 제외한 심폐기능(6분 걷기), 유연성(앉아 윗몸 앞으로 굽히기), 근 기능(윗몸 말아 올리기), 순발력(제자리 멀리뛰기)을 적용시켜 측정하였다. 통제집단과 실험집단의 상호작용 효과를 알아보기 위해 Two-way Repeated Measure ANOVA를 실시한 검사 결과는 심폐기능과 순발력에서는 유의한 차이가 있는 것으로 나타났지만, 유연성과 근 기능에서는 유의한 차이가 없는 것으로 나타났다. 4개의 변인 중 3개변인(심폐기능, 유연성, 근 기능)은 인라인스케이트 프로그램이 건강 체력 향상에 영향을 미친것으로 나타났으며, 1개의 변인(순발력)은 사전검사 보다 사후검사에서 영향을 미치지 못한 것으로 나타났다. 사전 사후 검사에서 향상된 것으로 확인된 3개 변인의 결과에 따라 결론적으로 발달장애 학생들의 인라인스케이트 프로그램 적용은 건강 체력 향상에 긍정적인 영향을 미치는 것으로 나타났다.

홍어 껍질 유래 콜라겐 펩타이드를 한외여과막을 이용하여 분자량의 크기를 1,000 Da 이하와 1,000 Da 이상으로 분리하고 그 효과를 비교하고자 하였다. 각각의 시료를 비만 유발 실험동물인 db/db mice에 체중당 200 mg의 콜라겐 펩타이드를 8주간 투여하였다. 본 연구의 결과는 콜라겐 펩타이드를 투여한 군에서 비만대조군에 비해 체중 증가량의 감소, 혈액 및 간조직의 활성산소 농도의 감소, 간조직의 산화적 스트레스가 완화된 것으로 나타났다. 또한 콜라겐 투여군에서 염증반응과 관련된 간조직의 핵전사인자(NF-κB) 및 효소(COX2, iNOS), 염증성 사이토카인(IL-6)발현이 비만대조군에 비해 유의적으로 감소하였다. 분자량의 크기에 따라 약간의 차이가 나타났지만, 전반적으로는 유의적이지 않았다. 따라서 홍어 콜라겐 펩타이드의 비만에 의해 유발된 염증반응이 억제되었는데, 이는 콜라겐의 산화적 스트레스 완화작용에 기인한 것으로 사료된다.

The feeding habits of Okamejei kenojei were studied using 242 specimens collected from October 2010 to September 2011 in the coastal waters of Gadeok-do, Korea. O. kenojei was carnivorous feeder that consumed mainly shrimps, crabs, and fishes. Its diet also included small quantities of stomatods, cephalopods, amphipods. The size of O. kenojei ranged from 10.4 to 47.4 cm in total length (TL). O. kenojei showed ontogenetic dietary shift. <15.0, 15.0-19.9 cm size classes fed mainly on shrimps and amphipods. 20.0-24.9 cm size class fed mainly shrimps and crabs. Thereafter, shrimps and crabs were decreased with ontogenesis while fishes and cephalopods were increased. Increasing size, the mN/ST were constantly decreased, but mW/ST were constantly increased.

To obtain geographical range and growth–kinetics parameters of mottled sake (Beringraja pulchra) populations in the Yellow Sea, three mark–recapture experiments were carried out. Overall, 991 tagged individuals were released, and 4.1% of them were recaptured with the mean release period of 339 d (range, 8–1,420 d) and the mean growth rate of 1.4 cm mon–1 (female, 1.5 cm mon–1; male 1.3 cm mon–1). In the first experiment, 667 individuals were released at Heuksan Island from April to June, 2007–2009, and 30 individuals were recaptured mainly at the north and the north–east coasts of the island, indicating absence of migration to the south of the island. In the second experiment, 323 individuals were released at several fishing grounds scattered in the Yellow Sea in 2010–2013, and 11 individuals were recaptured at points deviated to all directions from the releasing points. As the last, one individual was released with pop–up satellite archival tag at a costal point (34°37.2’N, 124°59.3’E) off Hong Island on May 21, 2010. The tagged individual migrated to a north–east location (35°50.4’N, 126°03.6’E) of Eocheong Island by Aug. 25, 2010. The data archived for the three months in the tag indicated that the migration path had depths of 48–80 m and temperature of 12.6–14.4°C. The results indicated that mottled sake populations had a localized habitat ranges at the north of Heuksan Island and the west of Hong Island while growing at the rate of 1.4 cm mon–1.

To estimate the mesh selectivity of gillnet for ocellate spot skate (Okamejei kenojei), the field tests were carried out 12 times with six different mesh sizes (121.2mm, 137.7mm, 151.5mm, 168.3mm, 178.2mm, 189.4mm) in the coastal waters of Taean, Chungcheongnamdo of Korea, 2010~2011. In the field tests, the total number of species was 31, and that of catch was 1,410 and the total weight was 618,006g. The number and weight of ocellate spot skate which is main target in this study were 1,004 and 434,592g, respectively. The catch in number of ocellate spot skate occupied about 71.2% in total catch. The others of catch species were marbled sole (8.4%), sea raven (4.4%), japanese swimming crab (4.2%) and flatfish (4.1%) and so on. The range of body disk width (DW) of ocellate spot skates which were caught in this study was 15.2~35cm and the mode was 27~29cm. The estimation equation of mesh selectivity using the extended Kitahara's method was expressed as s (R)=s(DW/m)=exp{(-0.56R3-1.80R2+12.96R-9.99)-4.26}. The optimum value of DW/m for 1.0 of retention probability in this estimation equation was estimated 1.899 and DW/m was estimated to be 1.194, 1.314, 1.395, 1.461 and 1.520 when the retention probability were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively. When applied to the retention probability of 0.5, the optimum mesh size was estimated to be 177.0mm on first maturity disk width 26.9cm of ocellate spot skate.

Catches, CPUE, fishing season, disc width composition and fishing ground were studied to rebuild skate ray, Raja pulchra resource by the offshore longline fishery in Heuksan-do, Korea. Annual catches and CPUE of skate ray were increased from 2003 to 2010 (CPUE: from 2007 to 2010) continuously. The main fishing season of the skate ray was from December to next May. Disc width at 50% maturity for Raja pulchra by sex were estimated to be 65.83cm, 57.01cm by female and male respectively. The range of disc width was 22.3-112.0cm and the average disc width was 66.9cm, 60.0cm by female and male of Raja pulchra respectively during 2007-2010. Annual average of disc width of female skate ray was decreased from 2007 to 2010. The fishing grounds were formed from the coastal water off Hong-do to the coastal water off Gyeogyeolbiyeol-do, Korea. The center of fishing ground in October was formed in the northwestern coastal water off Gyeogyeolbiyeol-do and separated from that of the other months.

This study was conducted to investigate the quality characteristics of cookies prepared using skate powder (0, 1, 3, 5, 7%) as a substitute for flour. The pH of the cookie dough decreased significantly in response to the addition of all levels of skate powder. However, there were no significant differences in the dough values among the test groups. Furthermore, when the spread factor values were compared among groups, they were found to be inversely proportional to the skate powder concentration. In addition, the Hunter's color L, a and b values decreased significantly as the level of skate powder increased. Moreover, the addition of 1-7% skate powder resulted in increased hardness, cohesiveness, springiness, and brittleness when compared to the control. Finally, the results of the sensory evaluation and acceptance test showed that the cookies containing 3% skate powder had the highest scores.

2006년 6sim8월 국내 유통 중인 홍어회의 미생물학적 이화학적 품질을 조사한 결과 홍어회는 다른 어패류와 달리 신선 상태가 아닌 숙성 후 섭취하는 제품으로 pH가 9 내외의 수준이고, 암모니움을 함유하고 있으며, 다른 신선식품 보다 VBN 값이 15sim30배 정도 높았다. 숙성 홍어회의 미생물 오염 지표인 총균수 수준이 대다수 제품에서 식품 공전 상 잠정규격인 5 log CFU/g보다 높게 검출되었으며, 대장균군이 검출된 사례도 18건 중 1건이 있었고, 병원성 미생물인 S. aureus가 검출된 사례도 18건 중 2건이 있었다. 또한 약 5 log CFU/g 수준의 S. aureus를 숙성된 홍어회의 가식부위에 접종했을 때 저장 10일 째 일정 수준 (2 log CFU/g) 감소하긴 했지만, 3 log CFU/g 수준의 S. aureus가 10일 이상의 저장 기간에 걸쳐 유지되는 것을 확인할 수 있었다.

The purpose of this study was to investigate the effects of skate (Raja kenojei) flour on the functional and sensory characteristics of Mandupi. Mandupi samples were prepared with wheat flour along with the addition of different amounts of skate flour, followed by functional measurements and sensory evaluations. According to the amylograph data, the composite skate flour-wheat flour samples had increased gelatinization temperatures with increasing skate flour content; whereas initial viscosity at 95℃, viscosity at 95℃ after 15 minutes, and maximum viscosity were reduced. In terms of color values, L and b values decreased, but the a-value increased with increasing skate flour content. Furthermore, the addition of skate flour increased hardness, springiness, chewiness, and adhesiveness in the samples. Overall, based on sensory evaluations, the Mandupi containing 5% skate flour was preferred over the other samples.

In this study, the physicochemical and microbiological properties of market-available skate (Raja kenojei) kimchi were evaluated in comparison to long-term fermented Baechu kimchi. The comparative results for the skate (Raja kenojei) and Baechu kimchi products are as follows: salt concentrations = 3.40% and 3.95%, respectively; pH and acidity values = 4.01 and 3.90, and 0.65% and 0.82%, respectively; redox potential Eh values = 119.82 mV and 123.08 mV respectively; reducing sugars levels = 15.51 mg% and 13.23mg%, respectively; ascorbic acid levels = 24.21mg% and 22.18mg%, respectively; color L-values = 46.86 and 44.54, a-values = 15.46 and 12.28, and b-values = 29.94 and 28.36, respectively; hardness properties = 11.36 kgf and 10.23 kgf, respectively; hot water soluble pectin (HWSP) contents and sodium hexametaphosphate soluble pectin (NaSP) contents = 15.23% and 17.35%, and 32.51% and 29.64%, respectively; hydrochloric acid soluble pectin (HClSP) contents = 55.1% and 53.2%, respectively; total viable cell counts = 4.78×108 and 1.35×108, respectively; lactic acid bacteria counts = 5.18×105 and 1.32×105, respectively; and yeast levels = 8.52×105 and 5.23×105, respectively.

To investigate of the content of fatty acids and cholesterol level in Raja Skates, the skate was purchesed from Yangdong Fisheries market in Kwangju, Korea. The experimental skate contained moisture 77.1%, crude protein 20.5%, crude lipid 0.68% and ash 1.72% as the general components. The fatty acids composition of skate are 28 kinds, such as 10 kinds of saturated fatty acid and 18 kinds of unsaturated fatty acid. There are 5 kinds of odd numbered fatty acid, such as C15:0, C17:0, C19:0, C25:0. Lignoceric acid shows 11% content. As an unsaturated fatty acid, getoleic acid, C22:1: selecholeic acid, C24:1:9, 12-hexadecadienic acid, C16:2: trans-linolelaidic acid, C18:2:13, 16-docosadienoic acid, C22:2: are analyzed as the particular one. The p/s ratio of skates is 1.02 and n-3/n-6 ratio of Skates is 0.82, respectively. The content of cholesterol level of Skates muscle is less than 20mg%, and liver contains 300-500 mg% and Nechang-tang contains 100mg% each.

For the purpose of reuse the wasted by-products from the skate process to the health functional food or medicinal material, chondroitin sulfate was extracted from the skate cartilage with the method of hydrolysis with protease enzyme, and the contents of chondroitin sulfate and hydrolyzed protein were measured qualitatively and quantitatively. The effects of chondroitin sulfate on body weight or liver weight changes, hepatotoxicity elimination and anti-inflammatory actions were measured from in vivo test with feed-treated mice. From the hydrolytic extraction of skate cartilage with the mixture of 1% alcalase and 1% protease for 4 hours, the extraction yield of chondroitin sulfate was about 32.55%. The content and molecular weight of chondroitin sulfate was 26.63% and 2.85×105 Da., respectively and the content ratio of chondroitin sulfate to protein was measured to 1 to 2.76 with gel permeation chromatography. For the odor component, trimethylamine decreased about 30% but almost not ammonia from chondroitin sulfate with the treatment of activated carbon. From the feeding chondroitin sulfate to mice, the control effect of body and liver weights decrease was measured, anti-inflammatory action and hepatotoxicity elimination action were also measured. From these results, process operation conditions for manufacturing of chondroitin sulfate were suggested.

The aim of this study was to investigate and development collagen peptide materials from skate skin. Protein and fat content of collagen peptide showed about 95% and 0.1%, respectively. Average molecular weight of collagen peptide was measured as 1,015. In the analysis of amino acid, glycine and hydroxy proline content in collagen peptide was 19.32% and 16.25%, respectively, showing a typical characteristics of the collagen peptide. In obese db/db mice ingested 500 mg/day of collagen peptide for 18 days, the amounts of food and water intake were decreased considerably, contents of triglyceride, total cholesterol were decreased significantly in white adipose tissue of db/db mice. The final yield of collagen peptide was 17.23% in the optimized process for mass production. These results indicate that collagen peptide from skate skin may serve as candidates of fat reduction in adipose tissue and could be used as functional food and cosmetic ingredients.

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 ㎝ in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at 8℃, 13℃, 18℃, water temperature (12.8 to 24.2℃), and the best hatching temperature was 18℃. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.

Physicochemical and functional properties of collage from skate skin (Raja Kenojei) are examined depending on pH and NaCl concentration in the medium. The solubility decreased as NaCl concentration increased but, turbidity increased as concentration of collagen increased. Oil-holding capacity and water-holding capacity were similar to other fish skin collagens. Emulsion activity, creaming stability, and viscosity were lowest at where pH levels were isoelectric point regions of collagens. However, the higher pH values at 7.0-9.0 caused increasing foam expansion, foam viscosity, and gel strength. These results indicated that collagen from skate skin could be used as a functional ingredient for food and industrial applications.