• 한국수산과학회지
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• 제37권2호
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• pp.77-84
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• 2004

The powder and liquid products of seasoned and smoked skipjack tuna (Euthynus pelamis) was manufactured by using small skipjack tuna (1-2 kg, 20-30 cm) captured in the East Sea, Korea. Smoking was done three times at $80^{\circ}C$ for 8 hrs to decrease the moisture content below $15\%.$ The seasoned and smoked skipjack tuna powder with liquid smoke showed the lower pH than the control. The pH, VBN, amino nitrogen content, and TBA value were increased slowly as storage period was increased at room temperature. Liquid smoke decreased the production of animo nitrogen and VBN. Vacuum packaging was efficient for inhibiting the deterioration and the microbial growth of the seasoned and smoked skipjack tuna powder product.

• 한국수산과학회지
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• 제38권4호
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• pp.219-225
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• 2005

We studied the anticancer, antioxidative, ACE inhibitory, antithrombic, and cerebral ischemia inhibitory activities, of low molecular weight substances fractionated from the seasoned and smoked products of skipjack tuna (Euthynus pelamis). Low molecular weight substances fractionated from the liquid extract of seasoned and smoked skipjack tuna powder showed 7 peaks on gel permeation chromatography. Anticancer activity was the highest at Peak 3 $(54.23%)$ followed by Peak 4 $(41.58\%)$. The potency order of antioxidative activity was the highest at Peak 3 $(94.14\%)$ followed by Peak 2 $(82.07\%)$ and Peak 5 $(81.24\%)$. ACE inhibitory activity was the highest at Peak 3 $(67.27\%)$ followed by Peak 5 $(45.62\%)$. But there was weak anti thrombotic effect (PT and APTT) in the low molecular weight substances of the seasoned and smoked products of skipjack tuna. Cerebral ischemia inhibitory activity was the highest at Peak 3 $(80.0\%)$ followed by Peak 5 $(40.0\%)$.

• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1622-1633
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• 2002

The effects of tuna oil supplementation (0, 1, 2 and 3%) to pig diets on growth and carcass yield as well as meat quality were determined in 40 crossbred pigs. Animals were fattened from 30 to 90 kg of live-weight. Twenty-four hours after slaughter, following various early- and late-post mortem measurements, loin, backfat and belly were prepared from the carcasses. Bacon was produced from the belly part by curing and smoking. Neither performance (feed intake, daily gains, feed conversion efficiency) nor carcass quality (slaughter weight, dressing percentage, lean percentage, nutrient composition of the loin) were significantly affected by tuna oil supplementation. Tuna oil also had no clear effects on early- and late-post mortem meat quality traits, water-holding capacity and tenderness of the M. longissiumus dorsi (LD). Colour traits of LD and backfat, and backfat firmness were not significantly affected by tuna oil, either. However, there was a certain trend to elevated fat contents of LD (and bacon), but not of backfat, with increasing levels of tuna oil in feed. Pigs receiving elevated proportions of tuna oil expressed lower VLDL cholesterol and triglyceride concentrations in blood plasma, whereas the cholesterol content of LD, backfat and bacon did not reflect this trend. Effects of tuna oil on fatty acids in LD, backfat and bacon were often small in extent, except those concerning the long-chain polyunsaturated fatty acids. With 3% tuna oil in the diet, the contents of the particularly desired omega-3 fatty acids, C20:5 and C22:6, were 0.1 and 0.2 g/kg in LD. The corresponding values for backfat and bacon were 2.6 and 12.6 g/kg, and 1.3 and 9.2 g/kg, respectively. Tuna oil supplementation was associated with significant adverse effects on flavour and overall acceptance of bacon (not significant in LD although numerically the same trend was noted), but these effects on sensory ratings were limited in extent. Also shelf life of the products, determined as TBA value after different storage periods at $4^{\circ}C$ in LD, backfat and bacon, was significantly reduced. Overall, the present study suggests that omega-3 fatty acids may be enriched in pork by feeding tuna oil with few undesired side-effects, particularly those on sensory perception and shelf life, suggesting immediate consumption of the products is advisable. Most economically important traits (performance, slaughter and physical meat quality) remained unaffected.

• 한국수산과학회지
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• 제41권6호
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• pp.419-426
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• 2008

Physicochemical characteristics of gelatin extracted from abdominal skin of yellowfin tuna (Thunnus albacares), were investigated by comparing its proximate composition, pH, amino acid composition, viscoelastic properties, gel strength and SDS-PAGE patterns, with those of bovine and porcine gelatins. The effects of gelatin concentration, maturation time, heat and freeze treatments on the gel strength of yellowfin tuna abdominal skin gelatin were studied. Amounts of $\alpha$-chains, $\beta$- and $\gamma$-components of yellowfin tuna abdominal skin gelatin were higher than those of the two mammailan gelatins. Yellowfin tuna abdominal skin gelatin had the lowest imino acids (proline and hydroxyproline) content, which was consistent with that of other fishes. However, yellowfin tuna abdominal skin gelatin was highest in glycine, alanine, and lysine. The gel strengths of all gelatins were proportional to the concentration of gelatin, but yellowfin tuna abdominal skin gelatin exhibited the greatest gel strength at each concentration. Yellowfin tuna abdominal skin gelatin required a longer maturation time than the two mammalian gelatins to form a firm gel. Higher heating temperature decreased the gel strength of yellow fin tuna abdominal skin gelatin more than in the two mammalian gelatins. Freezing decreased the gel strength of bovine gelatin only slightly, but longer freezing times resulted in greater reductions in gel strength in the yellowfin tuna abdominal skin and porcine gelatins.

• Journal of Nutrition and Health
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• 제38권1호
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• pp.20-29
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• 2005

This study is conducted to determine the effects of dietary levels of corn and tuna oils on the formation of preneoplastic lesions in die-thylnitrosamine (DEN) induced rat hepatocarcinogenesis. Weanling male Sprague-Dawley rats were fed 2.5, 5, 15, 25% (w/w) corn or tuna oils. Hepatocellular carcinogenesis was induced by DEN (200 mg/kg body weight) and two-thirds partial hepactectomy was carried out 3 weeks later and were sacrificed 8 weeks after DEN initiation. Tuna oil group showed smaller area of placental glutathione S-transferase (GST-P) positive foci than com oil group. Com oil group of 25% (w/w) showed the widest area of GST -P positive foci, and tuna oil group showed significantly smaller area of GST-P positive foci than com oil in 25% (w/w) level but had no differences between oil levels. Thio-barbituric acid reactive substances (TBARS) content was the highest in 25% (w/w) level of tuna oil group fed long chain and highly polyunsaturated fatty acids. Also serum ${\gamma}$ -glutamyltranspeptidase (GGT) activities in 25% level of tuna oil group were significantly higher than by other levels. As oil contents increased, glucose 6-phosphatase (G6Pase) seems to decrease in com oil groups but remained the same in tuna oil groups. Glutathione reductase (GR) activities were significantly higher in tuna oil group, and the higher the level of tuna oil, the higher GR activities. But Cu/Zn superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities didn't seem to be influenced by levels and kind of dietary fats. Therefore, as oil levels increased, com oil rich in n-6 fatty acids promoted carcinogenesis but tuna oil rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) of n-3 fatty acids suppressed. Although lipid peroxidation products were elevated in 25% (w/w) tuna oil group, GST-P positive foci didn't increase. Therefore pre-neoplastic lesions might be reduced through mediation of a lipid peroxidation process in tuna oil. As fat contents of tuna oil increased, elevated GR activities may give a rise to produce more reduced glutathione in order to protect against free radical attack, and high G6Pase activities remained the same and they contributed to membrane stability. So tuna oil diet seems to protect hepatocarcinogenesis.

• Fisheries and Aquatic Sciences
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• 제26권10호
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• pp.593-604
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• 2023

Post-harvest handling and hygienic level of aquatic products significantly affect the quality and level of safety. Cold chain control is one of the determining factors for the quality of fish and the bacterial community that grows on the fish. Identification of spoilage bacteria and pathogens in aquatic products must be made because it will determine the physical and chemical quality. A molecular identification method with high sensitivity is the solution. This study aims to identify the quality of fish and bacterial communities that grow. The research procedures included sample collection, pH measurement, drip loss measurement, transportation and cold storage treatment, DNA extraction, DNA sequencing, sequence analysis, and bioinformatics analysis. The conclusion obtained from this study is that the simulation of the cold chain system applied to eastern little tuna does not significantly affect changes in the water activity value, pH, and drip loss. The insignificant change indicates that the eastern little tuna samples are still in good quality. The bioinformatics analysis showed the highest diversity and abundance of the bacterial community came from the Gammaproteobacterial class.

• 한국수산과학회지
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• 제44권6호
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• pp.591-596
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• 2011

The present study examined the physical properties of biofilms manufactured from yellowfin tuna Thunnus albacares skin gelatin with the aim of developing a biofilm from fisheries by-products to replace mammalian sources. The physical properties of biofilms from yellowfin tuna gelatin were compared with those of biofilms from porcine gelatin. The yellowfin tuna gelatin biofilm exhibited higher tensile strength (69.08 MPa) and greater elongation (14.32%) than did porcine gelatin biofilm (50.50 MPa and 10.21%, respectively). The ${\Delta}E$ and YI (yellowness index) Huntercolor values of yellowfin tuna gelatin biofilm were three-fold and 15-fold higher, respectively, than values for porcine gelatin biofilm. The opacity value of yellowfin tuna gelatin biofilm was higher than that of porcine gelatin biofilm. The stability against water of yellowfin tuna gelatin biofilm was lower than that of porcine gelatin biofilm at pH 3 to pH 11. Thermogravimetric analysis (TGA) indicated that the thermal stability of the biofilms was about $270^{\circ}C$ for porcine gelatin biofilm and about $250^{\circ}C$ for yellowfin tuna gelatin biofilm.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.3.1-3.11
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• 2023

Background: Studies on the risk of mercury (Hg) in Korean fishery products focus primarily on total Hg levels as opposed to methylmercury (MeHg) levels. None of the few studies on MeHg in tuna investigated tuna from Japanese restaurants. Few have evaluated lead (Pb), cadmium (Cd) and arsenic (As) in tuna. Thus, this study aimed to conduct a risk assessment by evaluating heavy metal concentrations in tuna from Japanese restaurants. Methods: Thirty-one tuna samples were collected from Japanese restaurants in the Republic of Korea. They were classified according to region and species. The concentration of heavy metals in the samples was analyzed using the Ministry of Food and Drug Safety Food Code method. The rate of exceedance of maximum residue levels (MRLs) and the risk compared to the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (%PTWI) were evaluated for risk assessment. Results: The mean of MeHg, Pb, Cd and As concentrations were 0.56 ± 1.47 mg/kg, 33.95 ± 3.74 ㎍/kg, 14.25 ± 2.19 ㎍/kg and 1.46 ± 1.89 mg/kg, respectively. No sample exceeded the MRLs of Pb and Cd, but 9.7% of the samples exceeded the MRL of MeHg. The %PTWIs of MeHg, Pb, Cd and As were 4.2037, 0.0162, 0.0244 and 1.1627, respectively. The %PTWI of MeHg by age group and sex was highest among men aged 19-29 years (10.6494), followed by men aged 30-49 years (7.2458) and women aged 19-29 years (4.8307). Conclusions: We found that 3 out of 31 samples exceeded the MRL of MeHg. The %PTWI of MeHg showed significant differences based on age and sex, and the value was likely to exceed a safe level depending on individuals' eating behaviors. Therefore, improved risk management for MeHg is required.

• Fisheries and Aquatic Sciences
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• 제25권7호
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• pp.390-402
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• 2022

In this study we investigate physical and chemical characteristics of immature and mature skipjack tuna (Katsuwonus pelamis) roes in fresh and dried forms. Fresh roes were studied for histological structure and also dried by three methods: hot air drying (HD), vacuum drying (VD) and freeze drying (FD). The obtained roe powders were analysed for proximate composition, color value, fatty acid composition, amino acid profile, equivalent umami concentration (EUC) and protein pattern. Unyolked oocytes were more common in immature roes, while fully yolked oocytes were more common in mature roes. All dried tuna roes contained high content of protein and lipid (69.31%-70.55% and 11.14%-16.02%, respectively). The powders obtained by FD provided the highest lightness value (L^*). The main fatty acid found in all roe powders was docosahexaenoic acid (DHA) (23.49%-27.02%). Glutamic acid, leucine, and aspartic acid were the three most abundant amino acids found in the powders (13.58-14.61, 8.06-8.42, and 7.81-8.39 g/100 g of protein, respectively). The mature roe powder obtained from HD provided the highest EUC value (73.09 g monosodium glutamate/100 g of samples). The protein band at molecular weight of 97 kDa (vitelline) represented the major protein. Therefore, dried tuna roe could be a functional ingredient source of protein and lipid rich in DHA and it also has potential to be used as taste enhancer with umami compound.

• 한국수산과학회지
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• 제33권2호
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• pp.158-163
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• 2000

참치 통조림 부산물인 자숙 가다랑어뼈를 칼슘제로 이용하기 위하여 칼슘추출조건 (추출방법 및 시간) 및 그 특성에 대하여 살펴보았다. 다량의 지질이 혼재한 자숙 가다랑어뼈로부터 칼슘제로 제조하기 위한 추출방법으로는 회화처리가 고온가압처리 및 진탕 처리보다 어취가 없으면서 백색을 나타내어 적절하였고, 백색도 및 칼슘 가용화율로 미루어 회화처리 최적조건은 $900{\circ}C, 15분$이었다. 최적조건에서 회화처리한 칼슘제의 응집은 진탕시간이 경과할수록 증가하여 16시간에 $86.1{\%}$로 최고에 달하였고, 용액 pH가 산성조건 (pH 2-5)에서는 거의 일어나지 않았으나, 중성조건 (pH 6-8)에서 급격히 증가하여 최대에 이르렀고, 알칼리조건 (pH 9-11)에서는 중성조건과 거의 차이가 없었다. 이상의 결과로 보아 최적조건에서 처리한 칼슘제의 경우도 중성부근에서는 가용화율이 낮아 기능성 개선제 또는 고차 수산가공품의 탄력 증강 등과 같은 품질개선제로 이용되기 위하여는 용해도 개선을 위한 적절한 처리가 시도되어야 할 것으로 판단되었다.