• Korean Journal of Environmental Agriculture
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• v.41 no.2
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• pp.108-114
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• 2022

BACKGROUND: This study was performed to determine residual characteristics of soil-treated metalaxyl-M and dinotefuran in crown daisy and to evaluate the risks from intake of the residual pesticides in the crop. METHODS AND RESULTS: The pesticide granules were treated in soil on two levels, and the plants samples were collected 51 days after seeding. The analytes were extracted and partitioned using the QuEChERS extraction packet (MgSO₄ 4 g, NaCl 1 g). The quantitative methods for metalaxyl-M and dinotefuran were validated in linearity, accuracy, and precision. Risk assessments of the pesticides were performed using Korea national nutrition statistics 2019. CONCLUSION(S): The residual concentrations of metalaxyl-M in crown daisy were 0.09-0.10 mg/kg (for the treatment at 6 kg/10 a) and 0.17-0.19 mg/kg (12 kg/10 a), respectively. The residual concentrations of dinotefuran in the crop were 0.53-0.75 mg/kg (3 kg/10 a) and 1.17-1.26 mg/kg (6 kg/10 a). The amounts of pesticides were less than MRL (Maximum Residue Limits) according to the Korean MFDS (Ministry of Food and Drug Safety). The HI (Hazard Index) of metalaxyl-M and dinotefuran for consumers was 0.0075% and 0.2250%, respectively. For females in the age between 50-64, the major consumer group, the HIs of the pesticides were <3%. Considering the consumption of crown daisy, they are not considered to be of toxicological concern.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1165-1170
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• 2010

A method for the determination of four pesticide compounds, urea (isoproturon), bis-carbamate (phenmedipham), thiocarbamate (pyridate) and vinyllidenediamine (nitenpyram) were examined and analyzed by HPLC with C-18 column ($250\;mm{\times}4.6\;mm$, $5\;{\mu}m$ diameter particle size). Mobile phase consisted of deionized water, acetonitrile and 50 mM $KH_2PO_4$ (pH 2.5). Isoproturon and phenmedipham analytical condition was isocratic elution of the column with 50% solvent A (acetonitrile) and 50% solvent B (deionized water); pyridate was 85% solvent A (acetonitrile) and 15% solvent B (deionized water) at a flow rate of 1 mL/min; and nitenpyram analytical condition was 90% solvent A (50 mM $KH_2PO_4$, pH 2.5) and 10% solvent B (acetonitrile) at a flow rate of 1 mL/min. In results, retention times were 6.12, 8.63, 9.40 and 12.76 min for isoproturon, phenmedipham, pyridate and nitenpyram, respectively. All injection volumes were $10\;{\mu}L$ and the limit of quantitation was 0.05 mg/kg for four pesticide compounds, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four pesticide compounds were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 70.18% to 118.08% and the standard deviations of all experiments were within 10%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1665-1673
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• 2014

The objective of this study was to compare the compositions and immuno-enhancing effects of 6-year-old red ginseng powder (RGP) with those of its fractions. RGP was subjected to extraction with 100% ethanol to obtain an ethanol fraction (E) and residue 1 (R1). Then, R1 was subjected to extraction with distilled water to obtain water fraction (W) and residue 2 (R2). Chemical compositions were as follows: 4.94% acidic polysaccharides and 1.56% ginsenosides (amounts of Rg1, Re, Rf, Rg2, Rb1, Rc, Rd, and Rg3) in RGP, 0.11% acidic polysaccharides and 6.99% ginsenosides in E, 4.93% acidic polysaccharides and 0.40% ginsenosides in R1, 0.50% acidic polysaccharides and 0.30% ginsenosides in R2, and 7.46% acidic polysaccharides and 0.61% ginsenosides in W. Immuno-enhancing effects of fractions from RGP were examined based on suppression of immune responses by cyclophosphamide. In the first fraction test, the antibody response to SRBCs increased significantly in the R1-treated group, but not the E-treated group. In the second fraction test, W showed higher immuno-enhancing effect than R1 and R2. W, which contained the highest amount of acidic polysaccharides, restored numbers of T and B cells, macrophages, as well as $CD4^+$ and $CD8^+$ T cells in the spleen suppressed by cyclophosphamide. These results suggest that acidic polysaccharides from red ginseng may be more effective than saponin in enhancing immune functions and reducing immunotoxicity of cyclophosphamide.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.243-251
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• 2020

In this study, we investigated pesticide residues in 207 agricultural products distributed by direct trade in the northern area of Gyeonggi Province. A total of 94 general agricultural products and 113 eco-friendly agricultural products collected from local grocers and cooperative stores were analyzed by multiresidue method for 263 pesticides using GC (gas chromatography)/ECD (electron capture detector), GC/NPD (nitrogen phosphorus detector), GC-MS/MS (tandem mass spectrometry), LC (liquid chromatography)/PDA (photodiode array detector), LC/FLD (fluorescence detector), LC-MS/MS. All samples showing pesticide residues were general agricultural products collected from local food stores. The pesticide residue levels of 14 samples (6.8%) were below the maximum residue limits (MRLs) and one of them (0.5%) exceeded the MRLs. Sixteen pesticides were detected from samples of the following produce items: spinach, young cabbage, perilla leaves, mallow, cucumber, chives and water dropwort. The safety of the detected pesticides was assessed by monitoring the daily intake estimate (EDI) and the daily intake allowance (ADI) based on the amount of pesticides detected. The ADI percentage range (the ratio of EDI to ADI) was 0.0134-61.6259% and there was no health risk connected with consuming agricultural products in which pesticide residues were detected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.790-797
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• 2011

We evaluated the antioxidant compounds and activity of the methanolic extracts of foxtail millet (FM), proso millet (PM), and sorghum (SG) using different pulverizing methods (pin mill and ultra fine). The particle size of the FM, PM, and SG were 102.12, 89.52, and $102.25\;{\mu}m$, respectively, using the pin mill pulverizer. The sizes were 9.43, 9.52, and $10.18\;{\mu}m$, respectively, using the ultra fine pulverizer. There was no difference in moisture, crude fat, ash, or protein content between the two different pulverizing methods. The total ${\gamma}$-oryzanol content of the FM using the pin mill and ultra fine pulverizers was 116.07 and $145.30\;{\mu}g$/g, respectively. The total polyphenol content of the SG using the pin mill and ultra fine pulverizers was 14.58 and 15.03 mg/g extract residue, respectively. There was no difference in total flavonoid or tannin content of the methanol extracts between the two different pulverizing methods. The major phenolic compounds in FM were pyrogallol, gallic acid, (+)-catechin, salicylic acid, ferulic acid, and rutin; in PM, they were pyrogallol, rutin, gallic acid, kaempfrol, and salicylic acid; in SG, they were (+)-catechin, salicylic acid, pyrogallol, myricetin, hesperidin and chlorogenic acid. SG had a higher radical scavenging activity than FM or PM extracts. The DPPH and ABTS radical scavenging activities of the SG extracts using the ultra fine pulverizer were 178.10 and 251.56 mg TE/g extract residue, respectively. We noted a significant correlation between free radical scavenging activity and polyphenolic compound.

• Journal of Food Hygiene and Safety
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• v.23 no.1
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• pp.6-14
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• 2008

Objective of this study was to investigate the residual levels of mercury (Hg) in soil for "Top-rice" area and its uptake into rice plant for making sure food safety as compared to "Top-rice" & common rice produced from 2005 to 2006. Hg was analyzed with the direct mercury analyzer (DMA 80, Milestone, Italy), which implements the US/EPA method 7473. The average concentration of Hg in paddy soil was 0.031 mg/kg, which was below at 1/25-1/65 fold of the threshold levels (concern level 4 mg/kg, action level 10 mg/kg) for soil contamination designated by "The Soil Environment Conservation Law" in Korea. The maximum residue level (MRLs) for Hg residue in the polished rice is not designated in Korea. Therefore, Hg contents in the polished rice of "Top-rice" brand and common rice were compared to other country's criteria. Hg contents in the polished rice of "Top-rice" brand was 0.0018 mg/kg, which was lower at 1/10-1/30 fold than the MRLs, 0.02 mg/kg of China criteria and 0.05 mg/kg of Taiwan criteria, respectively. Hg were 0.02788, 0.00896, 0.00182, 0.00189, 0.00166, 0.00452 and 0.00145 mg/kg in soil, rice straw, unhulled rice, rice hulls, brown rice, rice bran, and polished rice produced in 2006 "Top-rice" area, respectively. For the ratio of Hg as compared to Hg contents in soil, there were 0.321 of rice straw ${\gg}$ 0.162 of rice bran ${\gg}$ 0.068 of rice hulls > 0.065 of unhulled rice > 0.060 of brown rice> 0.052 of polished rice. And, the slope of Hg uptakes was steeped as following order; rice straw ${\gg}$ rice bran ${\gg}$ rice hulls > unhulled rice > brown rice > polished rice. It means that the more slope steeped was the more uptakes. For the distribution of Hg uptaken, there was 83.8% into rice straw, and 16.2% into unhulled rice, 2.8% into rice hulls, 12.4% into brown rice, 3.5% into rice bran and 9.7% into polished rice. Consequently, it was appeared that the Hg contamination in the polished rice should not be worried in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1508-1514
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• 2012

The purpose of this study was to evaluate the antioxidant contents and antioxidant activities of solvent fractions from methanolic extract of sericea lespedeza. To determine the antioxidant compounds in solvent fractions from methanolic extract, total polyphenolic, flavonoid, tannin, and proanthocyanidin contents were measured by spectrophotometric methods. Solvent fractions were evaluated for antioxidative capacity according to DPPH and ABTS radical scavenging activities. Total polyphenolic contents were 12.44, 3.61, 6.39, 27.11, 20.00, and 9.32 mg gallic acid equivalent (GAE)/g extract residue (ER), respectively. Total flavonoid contents were 2.94, 9.92, 7.77, 9.27, 5.11, and 2.66 mg catechin equivalent (CE)/g ER, respectively. Total tannin contents were 8.75, 10.04, 7.42, 17.32, 11.65, and 7.61 mg tannic acid equivalent (TAE)/g ER, respectively. Total proanthocyanidin contents were 346.09, 63.50, 103.76, 288.62, 231.99, and $358.48{\mu}g$ CE/g ER, respectively. DPPH radical scavenging activities of solvent fractions from methanolic extract of sericea lespedeza were 20.62, 5.16, 9.29, 20.80, 20.00 and 20.79 mg Trolox equivalent (TE)/g ER, and ABTS radical scavenging activities were 33.86, 9.24, 17.36, 33.76, 33.49, and 33.86 mg TE/g ER, respectively. SOD-like activities were 4.12, 0.61, 2.01, 9.89, 13.47, and 11.82 units/mL, and ${\alpha}$-glucosidase inhibition activities were 93.85 and 61.64% at concentrations of 50 and $25{\mu}g/mL$ in the water fraction, respectively. The results of this study show that notable antioxidant activities in sericea lespedeza have significant health benefits.

• Korean Journal of Food Science and Technology
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• v.53 no.4
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• pp.470-478
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• 2021

This study was conducted to monitor residual pesticides in a total of 527 school foodservice agricultural products from 2019 to 2020 in Incheon. Pesticide residues in the samples were analyzed by the multi-residue method in the Korean food code for 373 pesticides using GC-MS/MS, LC-MS/MS, GC-ECD, GC-NPD, and HPLC-UVD. By monitoring the pesticides, 12 (2.3%) of the 527 pesticides were detected, and 2 (0.4%) samples exceeded the maximum residue limit. Twelve types of pesticides were detected in the agricultural products of carrot, chard, chili pepper, chwinamul, crown daisy, parsley, perilla leaves, and spinach. As a means of risk assessment through the consumption of agricultural products detected with pesticide residues, the proportion of estimated daily intake to acceptable daily intake was estimated in the range of 0.0000-39.7425%. Results showed no particular health risk through the consumption of school foodservice agricultural products with pesticide residues.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.161-173
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• 2015

The multiresidue method 4.1.2.2 in Korea Food Code was extended for the analysis of 24 unregistered pesticide residues. The method includes acetonitrile extraction, liquid-liquid partition, Florisil SPE clean-up and GC analysis. The limits of quantification (LOQ) range of the method was 0.02~0.05 mg/kg for orange, brown rice and banana. The linearity for targeted pesticides were $R^2$ > 0.99 at the level ranged from 0.05 to 5 mg/L. Recovery test was performed at two concentration levels of LOQ and 4~10 times of LOQ. Recoveries and relative standard deviations (RSDs) of target pesticides were acceptable, showing 70~120% range and less than 20%, respectively, except for ethiprole, picloram and sulcotrion. This method is effectively applicable to routine analysis of target pesticides in orange, brown rice and banana.

• Journal of Food Hygiene and Safety
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• v.35 no.3
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• pp.225-233
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• 2020

By the standards and specifications for hygiene products, three test methods for formaldehyde are specified for each item type of hygiene product. After derivatization using acetylacetone and 2,4-dinitrophenylhydrazine (2,4-DNPH), formaldehyde is analyzed by spectrophotometer and high-performance liquid chromatography (HPLC). Validation of the three test methods was performed on tissue, diaper lining and waterproof layer, and panty liner products. The results of linearity (R²), limit of detection (LOD), limit of quantification (LOQ), recovery rate (%) and reproducibility (%), showed that all three methods are suitable for analyzing formaldehyde in hygiene products. After derivatization with 2,4-DNPH and cetylacetone, formaldehyde was analyzed at 0, 3, 6, 9, 24 and 48 hours by HPLC. Formaldehyde derivatized with 2,4-DNPH showed no statistically significant change in formaldehyde peak area over time (P>0.05). But, acetylacetone-derivatizated formaldehyde showed a negative correlation coefficient (r) over time (P<0.01). We investigated the residual amounts of formaldehyde in 205 hygiene products distributed in Busan. Among 74 disposable diaper products tested, 73 had low concentrations of formaldehyde (0.13-29.87 mg/kg). Moreover, formaldehyde was not detected in any of 78 tissue, 27 disposable paper towel, 12 disposable dishcloth, 7 paper cup, one brand of paper straw and 6 disposable napkin products.