• Analytical Science and Technology
• /
• v.24 no.2
• /
• pp.150-157
• /
• 2011

Aflatoxins are secondary metabolites of the molds of Aspergillus flavus and Aspergillus parasiticus. They are highly carcinogenic compounds and can affect a wide range of vegetable commodities such as cereals (especially corn), nuts, peanuts, fruits and oil seeds, in the field and during storage. In fact, oilseeds are often stored for weeks in conditions that promote the mould growth, and the possible consequent presence of aflatoxins in oilseeds can lead to their transfer in oil. In addition, aflatoxins can be found as a natural contaminant in multi-cereals and beans making baby food for infants and young-children. The objective of this study was to validate the liquid extraction method or develop an analytical method for edible oil and infant-children foods. Therefore, this study developed condition of extract for aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) in edible oil using a high performance liquid chromatography with florescence detector (HPLC/FLD). Aflatoxins were extracted from edible oil samples by means of MSPD (Matrix solid phased dispersion), utilizing $C_{18}$ as dispersing material and purified by using immunoaffinity column. The gression line coefficients were above 0.999. The recoveries for aflatoxins ranged from 85.9 to 93.0%, and relative standard deviations were below 5.7%. The new developed method of aflatoxins effectively enhanced recoveries by using MSPD-Immunoaffinity column compared with liquid extraction. The analytical method for liquid extraction of aflatoxin was appropriate for infant-children food. Reviewing the current method, the recoveries of aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) were 89.5~92.3%.

• Journal of Animal Science and Technology
• /
• v.48 no.4
• /
• pp.611-622
• /
• 2006

Fatty acid compositions and physicochemical properties of feta cheese made from bovine milk were studied. Nutritional compositions of feta cheese were fat 22.79%, protein 10.57% with moisture content of 59.87%. The log cfu/g of lactic acid bacteria in bovine feta cheese decreased from 10.25 to 7.95 and pH also changed from pH 6.22 to pH 5.55 during storage at 4℃ for 14 d aging. The color of feta cheese turned into more whitish (L-value, 100.1) with a red (a-value, 4.6) and gray (b-value,－4.1) color after 14day's aging. For the texture profile analysis of bovine feta cheese, resilience was increased significantly (p<0.01) throughout the aging periods and adhesiveness was rapidly increased right after progressing of aging at both temperatures, but no difference was found between the aging periods. Hardness, fracturability, gumminess and chewiness were gradually increased at 0℃, but no statistical significances were found. Springiness and cohesiveness were not changed at both temperatures. In organoleptic evaluations, organoleptic intensities in sweetness, milky taste and saltiness were significantly enhanced over those of the control cheese at the level of p<0.01, and masticatory texture at p<0.05 with the progress of aging to 14d. Organoleptic preferences were significantly (p<0.01) enhanced except smell, color, mouth feel, and masticatory texture with the aging. In the fatty acid compositions of feta cheese analyzed by gas chromatography, the content of SFA (52.61%) was slight higher than that of USFA (47.39%) composed with MUFA (28.98%) and PUFA (18.41%). Among the nutritionally important fatty acids; ω6 (9.27%) and ω3 (0.55%) fatty acids, CLA (0.12%), arachidonic acid (0.19%) and DHA (0.12%) were also found in bovine feta cheese.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.1
• /
• pp.26-30
• /
• 1993

To suggest a thermal diffusivity predicting equation for mixed meat products, heat penetration curves of pork products containing filefish meat were plotted in the temperature range of $80.44{\sim}121.03^{\circ}C$, and thermal diffusivities were calculated from the heat penetration curves. The ground pork was mixed with minced filefish meat and some additives such as lard, isolated soy protein, $1.5\%$ of table salt and $2\%$ of polyphosphate to control the composition and texture of products, and then stuffed into a model can. The heat penetration curves were plotted using a thermocouple fixed at the slowest heating point of the can. At constant heating temperature, the thermal diffusivities of the products increased linearly with increasing moisture content. The values of the products with constant moisture content also increased linearly with increasing heating temperature. The thermal diffusivities of the products with moisture content of $51.47{\sim}80.20\%$ could be predicted by following equation: $${\alpha}_p=(3.045+0.59{\cdot}X_w){\cdot}{\alpha}_w+0.0098{\cdot}10^{-6}{\cdot}X_w-0.4287{\cdot}10^{-6},(m^2{\cdot}s^{-1})$$ Maximal differences of the thermal diffusivities predicted with this equation were in the range of ${\pm}0.8\%$ compared with the practical values. This equation and another predicting equation obtained from the previous study for the pork product without fish meat could be simplified as following one equation, and the maximal differences of the thermal diffusivities predicted with this equation for both products with and without fish meat were in the range of less than ${\pm}2.5\%$ $${\alpha}_p=(2.290+0.54{\cdot}X_w){\cdot}{\alpha}_w+0.0024{\cdot}10^{-6}{\cdot}X_w-0.3535{\cdot}10^{-6},(m^2{\cdot}s^{-1})$$

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.3
• /
• pp.191-200
• /
• 1979

For the use of antarctic krill as a fond protein source its compositional characteristics were investigated as the first part of the work includes other subjects such as processing of drill paste, concentrates, and fermented or seasoned product. In general composition of fresh frozen and preboiled frozen krill on board, the contents of crude fat and free amino nitrogen were higher in the former than in the latter which contained a high amount of ash. VBN was rather high as much as 37.6 and $26.4\;mg\%$ in both fresh frozen and preboiled krill. The pH of drill homogenates was 7.1 to 7.2 in both cases. Such a low pH might be attributed to a long term storage and temperature fluctuations during frequent transshipping. The amino acid competition of fresh frozen krill meat showed relatively high amount of glutamic acid, aspartic acid, lysine, proline, and leucine while methionine, histidine, serine, tyrosine, and phenylalanine were lower. Among the essential amino acids lysine and leucine were higher and methionine was lower. In tile composition of free amino acid proline, lysing, arginine, and alanine were higher comparatively to the contents of histidine, aspartic acid, serine, and threonine. It is noteworthy for nutritional qualification that tile essential amino acids particularly as lysine were abundant similarly to that of fishes. Heavy metal contents of krill meat 0.039 to 0.048 ppm as Hg, 0.06 to 0.11 ppm as Pb, less than 0.32 ppm as Zn, 0.008 to 0.012 ppm as Cd, 0.61 to 0.68 ppm as Fe, 0.87 to 1.37 ppm as Cu, and nondetective as Cr. A high Cu content seems to be resulted by tile blood pigment of crustacea. The ratio,1 of edible portion to non-edible portion were 37:63 in fresh frozen and 42:58 in preboiled frozen krill respectively. Release of drip after thawing was more in fresh frozen than in preboiled frozen drill marking $36\%$ and $24\%$ of both respectively.

• The Korean Journal of Pesticide Science
• /
• v.20 no.3
• /
• pp.211-220
• /
• 2016

This study was to develop the analytical reference material of green-pepper for multi-residue analysis of pesticides. According to the ISO Guide 35, ISO Guide 13528 and EURL-PT protocol, the homogeneity, stability, assigned value and uncertainty were calculated to assess if it was suitable to be used as the proficiency test or quality control. The values of the within-bottle standard variation ($s_{wb}$) and the between-bottle standard variation ($s_{bb}$) were 1.7~3.7% of assigned value according to the requirement of the ISO guide 35. And, the uncertainty ($u^*{_{bb}}$) due to inhomogeneity was 0.8~1.1% for all pesticides. The storage stabilities of ten-pesticides at various conditions were assessed. For all target pesticides, the slop ($b_1$) values were smaller than the corresponding values of $[t_{0.95,n-2}{\times}s(b_1)]$ specified by the ISO guide 35, indicating that there were no statistically significant decreases in the concentration of the target pesticides when the analytical reference material was stored at room temperature ($20{\sim}30^{\circ}C$) for 7 days, freezing ($-20^{\circ}C$) for 30 days and deep freezer ($-80^{\circ}C$. except for bifenthrin, fenpropathrin) for 245 days. For proficiency test by using it developed by Korea Institute of Toxicology, inter-lab test was performed with eight organization performing the residual pesticide analysis. We found that there were some different results among them. Some were assessed as questionable or unacceptable for two pesticides and one organization didn't analyze the six pesticides. From these results, this green-pepper analytical reference material containing ten-pesticides could be used as a tool for the proficiency test to improve the reliability or consistency for pesticide residue's results.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.670-676
• /
• 2017

The purpose of this study is to analyze the shipbuilding structure of Hallabong Tangorover ten-day and monthly intervals, to determine whether the shipment control can stabilize and increase the income of Hallabong Tangor farmers by estimating and analyzing the price flexibility function of Hallabong, and to derive the policy implication. Looking at the overall market, the 1% increase in shipment volume indicates that the coefficient of price flexibility varies with time. The largest decline is in late December and early January. The dummy variable indicating the year in which the quality drops somewhat is statistically significant from March to May, and the average of them is -0.337%. This implies a greater importance for quality control and shipment control when quality is worse than good quality. The price flexibility, which indicates price changes due to 1% increase in monthly shipment volume of Hallabong Tangor, varies with time. The coefficient of price flexibility was the highest at -0.46 in December, but prices fell slightly due to quality improvement and the increase in special demand of New Year's demand, which was -0.33% in January, -0.261% in February, -0.307% in March, and -0.318% in April. Since then, the amount of storage has been gradually exhausted, and the price flexibility has fallen slightly to -0.243% in May and -0.236% in June. DUM02, which represents the year when more than 7 days after the New Year holidays are in February is from February to June (+). This indicates that the price decrease due to increase in volume is less than that in January when the New Year is in February. This indicates a greater necessity for shipment control when New Year holidays are in January.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.6 no.3
• /
• pp.189-203
• /
• 2008

The physical and chemical properties of radioactive waste drums, which have been temporarily stored on site, should be characterized before their shipment to a disposal facility in order to prove that the properties meet the acceptance guideline. The investigation of NDT(Nondestructive Test) method was figured out that the contents in drum, the quantitative analysis of free standing water and void fraction can be examined with X-ray NDT techniques. This paper describes the characteristics of X-ray NDT such as its principles, the considerations for selection of X-ray system, etc. And then, the waste drum characteristics such as drum type and dimension, contents in drum, etc. were examined, which are necessary to estimate the optimal X-ray energy for NDT of a drum. The estimation results were that: $(R)\acute{A}$ the proper X-ray energy is under 3 MeV to test the drums of 320 ${\beta}\S$ and less; $(R)\ddot{E}$ both X-ray systems of 450 keV and/or 3 MeV might be needed considering the economical efficiency and the realization. The number of drums that can be tested with 450 keV and 3 MeV X-ray system was figured out as 42,327 and 18,105 drums (based on storage of 2006. 12), respectively. Four testing scenarios were derived considering equipment procurement method, outsourcing or not, etc. The economical and feasibility assessment for the scenarios was resulted in that an optimal scenario is dependent on the acceptance guide line, the waste generator's policy on the waste treatment and the delivery to a disposal facility, etc. For example, it might be desirable that a waste generator purchases two 450 keV mobile system to examine the drums containing low density waste, and that outsourcing examination for the high density drums, if all NDT items such as quantitative analysis for 'free standing water' and 'void fraction', and confirmation of contents in drum have to be characterized. However, one 450 keV mobile system seems to be required to test only the contents in 13,000 drums per year.

• Applied Biological Chemistry
• /
• v.13 no.3
• /
• pp.207-218
• /
• 1970

Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.7
• /
• pp.432-440
• /
• 2015

Biochar, a by-product from pyrolysis of biomass, is a promising option to mitigate climate change by increasing soil carbon sequestration. This material is also considered to have potential to remediate a soil with heavy metal pollution by increasing the soil's adsorptive capacity. This study conducted the assessment of two biochars considering the climate change mitigation potential and heavy metal removal capacity at the same time. Two kinds of biochars (BC_Ch, TW_Ch) were prepared by pyrolyzing the biomass of burcucumber (BC_Bm) and tea waste (TW_Bm). The soils polluted with Pb were mixed with biochars or biomass and incubated for 60 d. During the incubation, $CO_2$, $CH_4$, and $N_2O$ were regularly measured and the soil before and after incubation was analyzed for chemical and biological parameters including the acetate extractable Pb. The results showed that only the BC_Ch treatment significantly reduced the amount of Pb after 60 d incubation. During the incubation, the $CO_2$ and $N_2O$ emissions from the BC_Ch and TW_Ch were decreased by 24% and 34% compared to the BC_Bm and TW_Bm, respectively. The $CH_4$ emissions were not significantly affected by biochar treatments. We calculated the GWP considering the production of amendment materials, application to the soils, removal of Pb, and soil carbon storage. The BC_Ch treatment had the most negative value because it had the higher Pb adsorption and soil carbon sequestration. Our results imply that if we apply biochar made from burcucumber, we could expect the pollution reduction and climate change mitigation at the same time.

• Clinical and Experimental Pediatrics
• /
• v.48 no.10
• /
• pp.1132-1138
• /
• 2005

Purpose : The mucopolysaccharidoses (MPSs) are a heterogeneous group of lysosomal storage disorders. They are caused by a deficiency of the enzymes involved in the degradation of glycosaminoglycans. Early recognition is important because recombinant enzyme replacement therapy is now available for MPS. We studied the clinical characteristics of 80 MPS children with the object of determining the epidemiological, clinical and radiological features in Korean MPS children. Methods : Diagnosis of MPS was confirmed by skin fibroblast enzyme analysis in 80 patients between February 1995 and December 2004. Charts were retrospectively reviewed for clinical and radiological findings, as well as for intelligence and speech evaluations. Results : Hunter syndrome (MPS type II) was the most prevalent type, appearing in 51/80 cases (64 %), followed by Sanfilippo syndrome (MPS III-18%), Hurler syndrome (MPS I-15%), and Morquio syndrome (MPS IV-4%). The average age at diagnosis was 5.5 years (range 1 to 20), and the male-to-female ratio was 4.7 : 1. Typical radiographic changes were observed in 45/54 cases (83%). Mitral regurgitation was the most common cardiac defect. Moderate to profound mental retardation and hearing loss were present in 14/35 cases (56%) and 33/38 cases (82%), respectively. Four MPS II patients had bone marrow transplantation, with mixed outcomes. Five MPS I patients are currently on enzyme replacement therapy. Conclusion : Our study showed a high proportion of MPS II cases (64%), which may represent population variability. By studying the clinical features of these patients, we hope to alert pediatricians of the warning signs of MPS.