• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.86-92
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• 1979

Antioxidants. BHA, BHT and PG were added to a commercial soybean oil at a level of 200 ppm, and the antioxidant-treated oils and a control oil were subjected to 30 min. heating at $150{\pm}2^{\circ}C$ and 23.5 hr. cooling at room temperature for 6 times. Variations of % antioxidant retention and some physical and chemical properties of the oils were investigated. The results of the present study were as follows. 1. The % retention of BHA, BHT and PG after the second heating and cooling was respectively 60.5, 55.7 and 40.5 %. That of BHA, BHT and PG after the 6th heating and cooling was respectively 5.7, 3.0 and 1.8 %. 2. The refractive indices and viscosity of the oils, including the control, increased slowly at first. but after 4th heating and cooling, these values increased rapidly. The color indices of the oils, including the control, increased very rapidly, but after the 2nd heating and cooling, the rates of the increase diminished considerably. 3. The efficiency of each antioxidant in suppressing peroxide, thiobarbituric acid, and acid value development decreased rapidly as the antioxidant contents of the oils decreased. After the 6th heating and cooling, the peroxide. thiobarbituric acid and acid values of the oils treated initially with the antioxidants did not differ appreciably from those of the control.

• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.222-226
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• 2013

A simple and sensitive analytical method was developed using gas chromatograph with electron capture detector (GC-ECD) and gas chromatograph-mass spectrometer (GC-MS) for determination and identification of chloropicrin. Because of small molecular weight and high volatile properties of chloropicrin, analytical method was developed utilizing headspace extraction and direct injection to the GC. The developed method was validated using hulled rice sample spiked with chloropicrin at different concentration levels, 0.1 and 0.5 mg/kg. Average recoveries of chloropicrin (using each concentration three replicates) ranged 77.7~79.3% with relative standard deviations less than 10% and calibration solutions concentration in the range $0.005{\sim}0.5{\mu}g/mL$, and limit of detection (LOD) and limit of quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. The result showed that developed analytical methods was successfully applied to detect a small amount of chloropicrin in hulled rice.

• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.361-372
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• 2023

Organotin pesticide is used as an acaricide in agriculture and may contaminate livestock products. This study aims to develop a rapid and straightforward analytical method for detecting organotin pesticides, specifically azocyclotin, cyhexatin, and fenbutatin oxide, in various livestock products, including beef, pork, chicken, egg, and milk, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The extraction process involved the use of 1% acetic acid in a mixture of acetonitrile and ethyl acetate (1:1). This was followed by the addition of anhydrous magnesium sulfate (MgSO₄) and anhydrous sodium chloride. The extracts were subsequently purified using octadecyl (C₁₈) and primary secondary amine (PSA), after which the supernatant was evaporated. Organotin pesticide recovery ranged from 75.7 to 115.3%, with a coefficient of variation (CV) below 25.3%. The results meet the criteria range of the Codex guidelines (CODEX CAC/GL 40). The analytical method in this study will be invaluable for the analysis of organotin pesticides in livestock products.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.397-403
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• 1992

This study was carried out for the development of assay method to quantify the soy protein content in meat homogenate, emulsion-type sausage and commercial meat products by Enzyme-linked Immunosorbent Assay(ELISA). The standard antigen was extracted before and after heat treatment. It was observed that the degree of reaction was not varied significantly according to the heating temperature. The recovery rate in meat homogenate and emulsion-type sausage was not varied significantly according to the heating temperature. The reaction was not interfered with fat and spices of the samples. Samples with 10% soy protein showed lower correlation than those with 2% and 5% soy protein. The recovery rate in commercial meat products showed difference individually. The correlation of some products with raw vegetable and wheat starch was relatively low.

• Korean Journal of Food Science and Technology
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• v.4 no.4
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• pp.252-258
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• 1972

Methods of separating yeast cells from oil-water-cell emulsion and subsequent purification of the recovered yeast have been studied. In addition, the results of preliminary feeding experiments in which a yeast grown on gas oil was incorporated into chick rations are reported. According to the present study, it appears that the recovery of the yeasts would be easier at pH 9, since the emulsion is relatively more unstable. A class of surface active agent at a concentration of 0.3% was found to facilitate the separation of the yeast from the emulsion. The use of electrolytes such as NaCl and KCl were found to be most effective in breaking the emulsion. Solvent treatment using iso-propyl alcohol and its azeotropic mixture with hexane at $58^{\circ}C$ are particularly suitable for purification of the yeast. In the feeding experiment it was found that 5 percent of the fishmeal in the control ration could be replaced by the yeast with no adverse effect on performance. However, when 8 percent of the fish meal in the control ration was replaced by the yeast, some effect on live-weight gain of the chicks was observed.

• Korean Journal of Environmental Agriculture
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• v.40 no.2
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• pp.134-141
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• 2021

BACKGROUND: The analytical method was established for determination of fungicide chinomethionat in several animal commodities using gas chromatography (GC) coupled with electron capture detector (ECD). METHODS AND RESULTS: In order to verify the applicability, the method was optimized for determining chinomethonat in various livestock products including beef, pork, chicken, milk and egg. Chinomethionat residual was extracted using acetone/dichloromethane(9/1, v/v) with magnesium sulfate and sodium chloride (salting outassociated liquid-liquid extraction). The extract was diluted by direct partitioning into dichloromethane to remove polar co-extractives in the aqueous phase. The extract was finally purified with optimized silica gel 10 g. CONCLUSION: The method limit of quantitation (MLOQ) was 0.02 mg/kg, which was in accordance with the maximum residue level (MRL) of chinomathionate as 0.05 mg/kg in livestock product. Recovery tests were carried out at two levels of concentration (MLOQ, 10 MLOQ) and resulted in good recoveries (84.8~103.0%). Reproducibilities were obtained (Coefficient of variation <5.2%), and the linearity of calibration curves were reasonable (r²>0.995) in the range of 0.01-0.2 ㎍/mL. This established analytical method was fully validated and could be useful for quantification of chinomathionat in animal commodities as official analytical method.

• Journal of the Korean Society of International Agriculture
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• v.30 no.4
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• pp.339-346
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• 2018

Cyanazine is a member of the triazine family of herbicides. Cyanazine is used as a pre- and post-emergence herbicide for the control of annual grasses and broadleaf weeds. This experiment was conducted to establish a determination method for cyanazine, as domestic unregistered pesticide, residue in major agricultural commodities using HPLC-DAD/MS. Cyanazine was extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and partitioned to dichloromethane for remove polar extractive in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized florisil column chromatography. On a $C_{18}$ column in HPLC, cyanazine was successfully separated from co-extractives of sample, and sensitively quantitated by diode array detection at 220 nm. Accuracy and precision of the proposed method was validated by the recovery experiment on every major agricultural commodity samples fortified with cyanazine at 3 concentration levels per agricultural commodity in each triplication. Mean recoveries were ranged from 83.6 to 93.3% in five major representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation(LOQ) of cyanazine was 0.02 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring(SIM) technique was also provided to clearly identify the suspected residue.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1244-1250
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• 2000

A method for simultaneous quantitative determination of plasticizers such as diethyl phthalate(DEP), di-n-propyl phthalate(DprP), di-n-butyl phthalate(DBP), di-n-pentyl phthalate(DPP), butylbenzyl phthalate(BBP), di-(2-ethylhexyl) phthalate(DEHP), dicyclohexyl phthalate(DCHP) and di-(2-ethylhexyl) adipate(DEHA), which are suspected as endocrine disruptors, in food was studied. A analysis method was optimized for the quantification of plasticizers in Jjambbong, which is a kind of fatty noodle, by using GC/FID. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 3.5, 5.3, 2.2, 2.2, 7.2, 1.7, 1.9 and 3.0 mg/kg, respectively. Much higher recovery was obtained by extraction with acetone/n-hexane(1:1) rather than hexane solvent system. The recovery of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 72.7, 85.9, 91.4, 97.1, 100.8, 103.2, 104.3 and 95.8% after 4 time extractions, respectively. The migration of plasticizers from PVC wraps into PVC wrap covered Jjambbong was conducted after shaking(120 rpm) for 30min at room temperature with chosen solvent system. It was found that the migration level of DEHA were 577, 706, 770 mg/kg into Jjambbong, respectively, while the other plasticizers were not observed.

• Proceedings of the Korean Journal of Food and Nutrition Conference
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• 2003.07a
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• pp.79-79
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• 2003

최근 소득수준의 향상과 여성의 사회진출로 인해 우리의 식생활도 많은 부분이 사회화되고 있다. 즉 완전조리식품과 반조리식품이 급격히 증가하고 있다. 기존의 인스탄트식품이 저가격, 반건강 특성으로 생각되어진 반면 최근 고가의 건강 지향적인 반조리식품으로 변화하고 있다. 이러한 경향은 식품가공기술 및 식품포장기술의 향상과 사회적요구에 부합된 결과로 사료된다. 이에 대표적인 경우가 다양한 소스류의 상품화 경향이다. 본 연구개발 사업에서 이루어지는 냉면소스도 가정에서 하기에는 번거롭고, 건강지향적 식생활로 메밀의 수효가 증가하여 냉면의 소비가 증가하리라 생각된다. 현재 시판되고 있는 기존의 몇몇의 제품들이 있기는 하나 제조공정, 보존상태 등에서 많은 문제점이 있다. 따라서 문헌 통하여 기존제품의 배합비를 조사하고, 냉면소스 배합비의 최적화를 위해 10여차례에 걸쳐 20종류의 소스에 대하여 배합비의 변화와 관능검사에 의해 배주스, 양파, 겨자, 마늘, 설탕, 물엿, 소금, 미원, 참기름, 고춧가루, 진간장, 생강즙, 식초, 파인애플로 구성된 소스를 개발하였다. 개발된 소스의 pH, 당도, 염도, 색차를 측정하여 관능검사의 결과와 비교 검토하였고, 식품재료의 차이에 의한 맛의 변화를 보정하기 위한 근거로 사용하였다. 저장성 검사를 위해 일반세균과 대장균을 검사하였다. 그 결과는 다음과 같다. 소비자들의 기호에 맞는 냉면소스를 개발하기 위해 다양한 식품의 배합을 시도하여 상품성이 있을 것으로 판단되는 recipe를 완성하였고, 일반인(주부)들을 상대로 한 호감도 조사에서도 좋은 성적을 나타내었다. 시료를 1주간격으로 한달간 실험한 결과 쇠고기가 들어 있는 제품을 제외하구 대장균은 검출되지 않았으며 일반세균은 위생법의 허용치내에 있었다. 쇠고기가 있는 제품은 가격상승과 저장성에 문제가 있어 이를 제하고 최종적인 레시피를 결정하였다.있었다. 그러나 식이 섭취상태와의 관련성은 나타나지 않았다. 이상에서 생활습관이 신체계측치 및 혈중 지질 농도와 일부 상관을 보이는 것을 알 수 있었으며, 건강위험 요인도 관찰할 수 있었다. 고지혈증은 심혈관계질환의 주요한 위험 인자로 알려져 있으며, 그 유발 요인에는 여러 환경적인 요인과 식이 요인이 있다. 또한 생활습관은 영양소의 섭취량에도 영향을준다. 이처럼 식이 요인과 생활습관은 단독 혹은 상호 영향을 주게 되므로 고지혈증 및 심혈관계질환을 개선하려면 식사요법과 생활습관 교정을 병행하여야 한다. 고지혈증의 원인 중의 하나로 지적되고 있는 음주와 흡연은 상호 유도작용이 있으므로 금연이나 절주를 하고자 할 경우 두가지를 동시에 자제해야 효과적일 것으로 생각된다. 폐경후 여성들에게 발생 빈도가 높은 심혈관질환의 위험요인인 고지혈증을 예방하고자 하는 노력은 폐경후 여성들의 삶의 질적 향상을 위해서도 매우 중요하다. 또한 균형식 섭취와 운동을 통해 혈중 지질 수준을 건강하게 유지하고, 비만으로의 이행을 방지함으로써 심혈관계질환을 예방하도록 하여야겠다.료보다 절반이하 수준이었다. Ferric citrate는 차이가 거의 없었으며 ferrous lactate는 70%수준이었다. 이상의 결과에서 철분강화우유에 사용하기 적합한 철분염은 ferrous lactate, ferric citrate였는데 특히 ferrous lactate는 제품의 이화학적 품질, 생이용성 측면 모두에서 가장 좋은 것으로 나타났다.다 높았으며, 1회당 평균 8.1$\pm$5.1개의 난포란을 회수하였다. investigation can be separated into sampling and analytical uncertainties, it can be used as a criterion where the resources for the inves

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.339-345
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• 2011

BACKGROUND: Recently in Korea, the import of agricultural products is rising due to the increasing amount of trade. Unregistered pesticides, allidochlor, propachlor, propham, cycloate, diallate and pebulate are widely used as pesticides for rice cultivation in foreign countries, while they are not registered in Korea. Therefore, the residue amount of imported agri-foods should be verified using the proper official analytical method for each of them that has not registered in Korea. METHODS AND RESULTS: This work was conducted to apply the official method of Korea Food & Drug Administration (KFDA) for determining multi class pesticide multiresidues in agricultural commodities. Brown rice and orange which have different characteristics as a matrix were selected as representative samples for residue analysis. The recoveries of cycloate, diallate and pebulate by GC/MS in fortified brown rice and orange with levels of 0.04~0.4 mg/kg were ranged from 82.8% to 110.3%. The quantification limits of three pesticides in brown rice and orange were 0.04 mg/kg. CONCLUSION: As a result, this method can surely be used as an official method for routine analysis of unregistered pesticides in Korea for imported agri-food.