• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.1030-1035
• /
• 2002

Despite health benefits derived from fish oil, polyunsaturated fatty acids (PUFAs) contained in fish oil are susceptible to lipid oxidation. To determine the optimum condition for maintaining good quality cooked fish during storage, mackerels were broiled with salt or soysauce condiments, and the lipid oxidation during 12 days of storage at refrigerated condition was measured. Peroxide value of broiled mackerel group with salt significantly increased after immediate cooking and maintained higher value throughout the storage period compare to the soysauce-added group, but showed similar value to the control group. Conjugated diene content in the soysauce-group was lower than the control and salt-added groups. Malondialdehyde content of broiled mackerel increased twofold and showed similar values in soysauce-added and the control groups during storage, whereas increased in the salt-added group significantly. Fatty acid compositions of the three mackerel groups changed after cooking, whereas that of the control group was almost stable during storage. In comparison with raw mackerel, the ratio of PUFA and saturated fatty acids decreased significantly, and the content of n-3 family fatty acid decreased from 25.53 to 20.63% in salted broiled mackerel. Soysauce group showed no reduction of PUFA with increasing storage time and showed the highest ratio of n-3/n-6 among the three groups at 10 days storage. Results reveal soysauce condiment protects against lipid peroxidation of broiled mackerel. Maillard reaction products (MRPs) found in soysauce might be responsible for the inhibitory effect and is a good condiment for extending storage life of cooked fish containing high amount of PUFA.

• Journal of Environmental Impact Assessment
• /
• v.29 no.3
• /
• pp.157-181
• /
• 2020

Sediments from rivers, lakes and marine ports serve as end points for pollutants discharged into the water, and at the same time serve as sources of pollutants that are continuously released into the water. Until now, the contaminated sediments have been landfilled or dumped at sea. Landfilling, however, was expensive and dumping at sea was completely banned due to the London Convention. Therefore, this study applied contaminated sedimentation soil of 'Royal Palace Livestock Complex' as soil purification method. Soil remediation methods were applied to pretreatment, composting, soil washing, electrokinetics, and thermal desorption by selecting overseas application cases and domestically applicable application technologies. As a result of surveying the site for pollutant characteristics, Disolved Oxigen (DO), Suspended Solid (SS), Chemical Oxygen Demand (COD), Total Nitrogen (TN), and Total Phosphorus (TP) exceeded the discharged water quality standard, and especially SS, COD, TN, and TP exceeded the standard several tens to several hundred times. Soil showed high concentrations of copper and zinc, which promote the growth of pig feed, and cadmium exceeded 1 standard of Soil Environment Conservation Act. In the pretreatment technology, hydrocyclone was used for particle size separation, and the fine soil was separated by more than 80%. Composting was performed on organic and Total Petroleum Hydrocarbon (TPH) contaminated soils. TPH was treated within the standard of concern, and E. coli was analyzed to be high in organic matter, and the fertilizer specification was satisfied by applying the optimum composting conditions at 70℃, but the organic matter content was lower than the fertilizer specification. As a result of continuous washing test, Cd has 5 levels of residual material in fine soil. Cu and Zn were mostly composed of ion exchange properties (stage 1), carbonates (stage 2), and iron / manganese oxides (stage 3), which facilitate easy separation of contamination. As a result of applying acid dissolution and multi-stage washing step by step, hydrochloric acid, 1.0M, 1: 3, 200rpm, 60min was analyzed as the optimal washing factor. Most of the contaminated sediments were found to satisfy the Soil Environmental Conservation Act's standards. Therefore, as a result of the applicability test of this study, soil with high heavy metal contamination was used as aggregate by applying soil cleaning after pre-treatment. It was possible to verify that it was efficient to use organic and oil-contaminated soil as compost Maturity after exterminating contaminants and E. coli by applying composting.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.3
• /
• pp.308-318
• /
• 2013

Korean soybean varieties, 'Seonyu' and 'Hwangkeum' were planted in 2012, and three temperature gradient, Tc($19.8^{\circ}C$, ambient temperatured), $Tc+1.7^{\circ}C$, and $Tc+2.5^{\circ}C$, were artificially created by controlling the green house system during seed filling period. Mature seeds that developed under these conditions were analyzed for variances in physicochemical properties. The 100-seed weight and seed-coat ratio of soybean were decreased, but small seed rate was increased by high temperature during seed filling period. Protein content was increased, but oil content was decreased significantly with increasing the seed filling temperature. The decrement of carbon to nitrogen ratio (C/N), and the increment of monosaccharide, fructose and sucrose, in seeds explained that carbohydrate assimilation during seed filling was restricted by high temperature. Rapid increments of seed volume and weight were observed in the seeds of high seed filling temperature, but as soaking time increased the highest values were observed in the seeds of ambient seed filling temperature. The 100-seed weight and seed-coat ratio of soybean were closely related not only to the increment of soaking volume and weight, but also the increments of total dissolved solids (TDS) and electro conductivity (EC). Whereas protein content and C/N ratio showed less relationship with the soaking properties, but they had a positive correlation with TDS and EC. From the results, it was considered that high values of TDS and EC in the seeds of high temperature were mainly due to the incomplete conversion of assimilates into storage compounds. However, sugar content showed less influence on the soaking properties and the values of TDS and EC.