• Journal of Aquaculture
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• v.17 no.2
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• pp.139-143
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• 2004

In the fish oil forced oxidized at 6$0^{\circ}C$ for 10 days, changes in the levels of peroxide (POV), anisidine (AnV), total oxidation (Totox), iodine (IV), acid (AV) and fatty acids composition were measured. The levels of POV, AnV and Totox remained unchanged or decreased after reaching the maximum. The concentrations of polyunsaturated fatty acids (PUFA) such as Docosa hexaenoic acid (DHA) or Eicosa pentaenoic acid (EPA) decreased with extended oxidation of fish oil. In saturated fatty acids (SFA) like C16:0, their concentration increased with decreasing PUFA. The ratios of PUFA/SFA and DHA/C16:0 decreased with extended oxidation of fish oil. Using a single parameter of POV, AnV, Totox, AV, IV, or fatty acids for evaluation of the quality of fish oil may prove difficult. Besides other parameters, the ratios of PUFA/SFA and/or DHA/C16:0 could be a good index to evaluate the quality of fish oil.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.255-260
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• 2002

Yukwa is a popular Korean traditional fried rice snack. The high fat content and porous structure of Yukwa cause it to rapidly become rancid, presenting difficult challenges for commercial distribution. In this study, an-tioxidant activities of green tea extracts (GTE) were evaluated in Yukwa fried in soybean oil (SBO), rice bran oil (RBO) and winterized rice bran oil (WRBO) during storage at 4$0^{\circ}C$ for 12 weeks. Lipid oxidation of Yukwa was determined by acid value (AV), peroxide value (POV), p-anisidine value(AnV), totox value and sensory evaluation. The addition of GTE to the oils reduced the increases in AV, POV, AnV, and totox. Totox increased most vapidly in Yukwa fried in SBO, fellowed by RBO>WRBO>SBO+200 ppm GTE>RBO+200 ppm GTE > WRBO + 200 ppm GTE (p<0.05). Sensory evaluation revealed that the addition of 200 ppm GTE delays rancidity in Yukwa by 7~8 weeks; providing compelling evidence that GTE is an effective antioxidant for Yukwa.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.824-827
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• 1994

Sardine oil was vacuum-steam deodorized at $170^{\circ}C$ with acid (acetic and citric acid) and ethanol solution as steam sources. Glycerol was added to fish oil to remove volatile odorous constituents. The storage stability of deodorized fish oil was determined by totox value, secondary parameter obtained from peroxide and anisidine values. Both deodorization with acetic acid solution and addition of glycerol to the oil resulted in improved storage stability. The totox values of fish oil deodorized with water, glycerol+water and glycerol+acetic acid solution were 936, 611, and 443, respectively after 10 days at $30^{\circ}C$. The result showed that acetic acid seemed to destroy the odorous constituents and glycerol accelerated the removal of odorous constituents, such as amines in fish oil.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.480-488
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• 2019

To ensure the safety of products containing omega-3 fatty acids, twenty fish and algae oil omega-3 products available in a Gyeonggi Province, South Korea market were analyzed for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, as well as for oxidative status. Of the tested products, 90% complied with the CODEX/FAO fish oil standards on a p-anisidine value (p-AV) limit of 20, and 80% complied with the CODEX/FAO fish oil standards on the TOTOX limit of 26, respectively. Fully 100% of the products complied with EPA/DHA content levels. In addition, 90% of the tested products met with a peroxide value (PV) limit of 10 meq/kg while 95% of products were within the a p-AV limit of 30. Also, 95% of the products had a calculated TOTOX value of 50, which is lower than the stringent limits used by the European and British Pharmacopeia and Australian authorities.

• Analytical Science and Technology
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• v.33 no.5
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• pp.215-223
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• 2020

The objectives of the present study were to assess the oxidative stability of South Korean n-3 (omega-3 fatty acid) supplements carried out from 2018 to 2019 and evaluate the influence of product characteristics on oxidative safety. A total of 76 n-3 supplements were analysed for oxidation safety by four markers, including acid value (AV), primary oxidation (peroxide value, PV), secondary oxidation (p-anisidine value, pAV) and total oxidation value (TOTOX). Among the supplements tested, 5.3 %, 55.3 %, 28.9 % and 46.1 % exceeded the international voluntary recommended levels for AV, PV, pAV and TOTOX, respectively. Purity (%) of products, remainder of expiration date (suggested shelf life), package in press through package (PTP) and products with additives had statistically significant differences oxidation assessment levels (p < 0.05). In addition, n-3 group found in Algae oil had significantly lower AV levels than the group that did not, and product with Alaska pollack oil, had significantly higher pAV levels than without group (p < 0.05). The high oxidation status of South Korean n-3 products in the present study could not be considered a public health problem right now. However, the levels of oxidation may affect a lot the efficacy and safety of using n-3 supplements. Thus, current oxidation safety limits should be reestablished by regulatory bodies to ensure the safety and efficacy of n-3 supplements, so that the standards could be applied to the products available to consumers.

• Food Science of Animal Resources
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• v.39 no.3
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• pp.446-458
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• 2019

The aim of this study was to investigate the oxidative status and quality characteristics of four animal skin-derived fats extracted using an identical extraction method. Pressurized hot water extraction, a green extraction method, was used to extract animal skin fats (duck, chicken, swine, and bovine skin). Multiple experiments were performed during accelerated storage at $60^{\circ}C$ for 90 days. Quality characteristics, such as extraction yield, iodine value (IV), fatty acid composition, and fat viscosity were determined. In addition, indicators for oxidative status, including acid value (AV), peroxide value (PV), p-anisidine value (p-AV), thiobarbituric acid reactive substances (TBARS), conjugated dienes (CD), and total oxidation (totox) values were evaluated. The fat extraction yield was highest in bovine fat, followed by duck, swine, and chicken fats. The IV was higher in duck and chicken fats. Duck fats contained the most unsaturated fats and the least saturated fats. Fat oxidation indicators, such as PV, TBARS, and totox values, were relatively higher in duck fats during storage compared to the other fats. Other indicators, including AV, p-AV, and CD, were similar in duck, chicken, and swine fats. Viscosity was similar in all the tested fats but markedly increased after 70 days of storage in duck fats. Our data indicate that duck skin fat was more vulnerable to oxidative changes in accelerated storage conditions and this may be due to its higher unsaturated fatty acid content. Supplementation with antioxidants might be a reasonable way to solve the oxidation issue in duck skin fats.

• Journal of Aquaculture
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• v.17 no.2
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• pp.144-150
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• 2004

This experiment was conducted to evaluate the parameters such as nutrient requirements, POY, AnV, Totox, VBN, total plate count, dietary fatty acids and amino acids composition, that are not included in the registered standard composition items required by the Ministry of Agriculture and Forestry, of a moist pellet (MP), three domestic extruded pellets (DEP-1, DEP-2, DEP-3), and two foreign extruded pellets (FEP-1, FEP-2) that are utilized by domestic flounder farms at present. The crude protein was added in excess of the dietary protein requirement in 6 kinds of feeds. When considering the proper PH ratio, it is obvious that protein was added in excess, especially in MP and FEP-2. Crude fat was also added in excess, especially in FEP-1. MP contained a higher dietary phosphorus content than formulated feeds, surpassing the dietary phosphorus requirement and greatly increasing the possibility for causing water pollution. The oxidation of fatty acid and decomposition of protein in MP were higher than in formulated feeds, and may also cause problems on fish farms. Also, it is difficult to store and manage MP, Among the fatty acids, EPA and DHA contents in MP were higher than those in formulated feeds. It is necessary to conduct further studies of EPA and DHA contents in formulated feeds. Lysine content in MP and FEP-2 could meet the dietary lysine requirement of flounder, however, the possibility of insufficient lysine content in the other formulated feeds was high and we considered that extra supplementation was necessary. Therefore, it is necessary to set up quality control standards according to fish species and sizes while considering the specific character of aquatic formulated feeds to restore the confidence of feed companies and aquaculturists to these feeds. This may be an opportunity to make an earlier change from MP to formulated feeds.

• Korean Journal of Food Science and Technology
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• v.51 no.1
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• pp.1-6
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• 2019

Horse fat was vacuum-extracted from fatty tissues of Jeju and Halla horse meat and their physicochemical properties were compared to those of commercial lard and beef-tallow. For color, ${\Delta}E$ was found to be decreased when crystallized. Although acid values of horse fat were higher than those of lard and beef-tallow, p-anisidine and totox values were lower. The iodine value of beef-tallow was the lowest (44.61), and those of horse fat and lard were similar (57.53-57.74). Only horse fat contained ${\alpha}-tocopherol$. The contents of ${\gamma}-tocopherol$ in Jeju and Halla horse fat, lard, and beef-tallow were 7.08, 4.57, 2.13, and 1.91 mg/kg, respectively. Palmitoleic acid ($C_{16:1}$) was found in horse fat. Melting and crystallization curves of horse fat displayed two endothermic and exothermic peaks which were differentiated from lard and beef-tallow. These results indicated that horse fat demonstrates different physicochemical properties compared to lard and beef-tallow, when applied to various types of lipid products.