• Food Science and Biotechnology
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• v.17 no.5
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• pp.1038-1046
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• 2008

This study was carried out to develop a small-sized biosensor based on surface plasmon resonance (SPR) for the rapid identification of insecticide residues for food safety. The SPR biosensor module consists of a single 770 nm-light emitting diodes (LED) light source, several optical lenses for transferring light, a hemisphere sensor chip, photo detector, A/D converter, power source, and software for signal processing using a computer. Except for the computer, the size and weight of the sensor module are 150 (L)$\times$70 (W)$\times$120 (H) mm and 828 g, respectively. Validation and application procedures were designed to assess refractive index analysis, affinity properties, sensitivity, linearity, limits of detection, and robustness which includes an analysis of baseline stability and reproducibility of ligand immobilization using carbamate (carbofuran and carbaryl) and organophosphate (cadusafos, ethoprofos, and chlorpyrifos) insecticide residues. With direct binding analysis, insecticide residues were detected at less than the minimum 0.01 ppm and analyzed in less than 100 sec with a good linear relationship. Based on these results, we find that the binding interaction with active target groups in enzymes using the miniaturized SPR biosensor could detect low concentrations which satisfy the maximum residue limits for pesticide tolerance in Korea, Japan, and the USA.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.356-363
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• 2012

The aim of this study was to utilize rice bran, the main waste product of paddy processing, in xanthan gum production by Xanthomonas campestris fermentation. Deffated rice bran was enzymatically hydrolyzed using cellulase, gluco-amylase, alpha-amylase and xylanase at various pHs and temperatures within 0-12 h. The highest sugar content reached at $35^{\circ}C$, pH 5.5 in 6 h with 41.66%. The enzymatic hydrolysate was used as the carbon source for xanthan gum production by X. campestris NRRL B-1459 and X. campestris pv. campestris. The highest productivities obtained were 21.87 and 17.10 g/L, respectively. Viscosity measurement for the obtained xanthan gums and commercial gum was carried out in gum solutions at various pHs and temperatures. The highest viscosity was reached with 1% gum solutions at $20^{\circ}C$ and pH 5.5 for all gums with viscosity values of 470, 131 and 138 mPa sec, respectively. This work has provided relevant scientific information about the use of rice bran, an abundant agroindustrial residue, to produce xanthan gum.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.232-240
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• 2009

The aim of this study was to determine the processing and reduction factors for ginseng and its commodities during ginseng processing to obtain information of pesticide residue in ginseng. For this study, azoxystrobin was used in two field containing 6 years old ginseng plants. Ginsengs were harvested and processed to obtain different commodities (Dried ginseng, red ginseng and ginseng water and alcohol extracts, red ginseng water and alcohol extracts) for pesticide analysis. The amount of residue levels from wonju and icheon for fresh ginseng were 0.05, $0.03\;mg\;kg^{-1}$ dried ginseng were 0.12, $0.14\;mg\;kg^{-1}$, red ginseng were both $0.05\;mg\;kg^{-1}$, ginseng alcohol extract were 0.28, $0.33\;mg\;kg^{-1}$, ginseng water extract were 0.22, $0.16\;mg\;kg^{-1}$, red ginseng alcohol extract were 0.31, $0.20\;mg\;kg^{-1}$ and red ginseng water extract were 0.09, $0.11\;mg\;kg^{-1}$ respectively. These data were under MRLs notified by KFDA. The processing factors for ginseng products were 3.25, 1.34, 7.84, 4.63, 6.15 and 2.56 respectively. The reduction factors for ginseng products were 1.19, 0.51, 3.41, 1.91, 2.74 and 1.00 respectively. These data showed increment during processing which could be due to concentration but considering water contents, residue levels were similar or decreased than the initial residue level during processing.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.248-254
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• 2015

Uptake of the triazole fungicides, fluquinconazole and tetraconazole from shoot part of onion was assessed by determining residual amounts of applied fungicides in edible and shoot parts of onion after the foliar application. Combined product of fluquinconazole and tetraconazole (14:7, v/v) as a 21% active ingredient of suspended emulsion formulation was diluted at ratio of 500 and 200 times and sprayed on the shoot part of onion after sealing its root part with absorbent paper. At 10 days after the pesticide application, fluquinconazole residue in the shoot part was the greatest as 5.2 mg/kg at 200 times-dilution treatment, while tetraconazole residue in this part was the smallest as 1.2 mg/kg at 500 times-dilution treatment. On the other hand, the pesticide residues in edible parts of onion at all the treatments were less than limits of detection, 0.01 mg/kg. However, fluquinconazole residues in the edible part of onion divided into three groups such as 1st, 2nd, and 3rd layers were detected at concentrations of 0.04 or 0.24 mg/kg, and these results show the different distribution of pesticides in onion depending on divided layers. In addition, chopped onions were soaked in pesticide solutions prepared with dilution of 1,000 times, cooked using three food processing types such as boiling, stir frying, and pickling, and the pesticide residues in them were analyzed. The analyzed results showed the largest pesticide dissipation in onion followed boiling process (76.9~92.6%).

• Food Science and Preservation
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• v.22 no.2
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• pp.218-224
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• 2015

Crickets have been used as crude drug for treating fever and hypertension in East Asia. This study was carried out to investigate the quality characteristics such as the microbial and nutrient contents of crickets (Gryllus bimaculatus) prepared with various processing conditions for use as food. These conditions included the lyophilization process (LP), hot-air process (HP, $90^{\circ}C$ for 7 hr), roasting process (RP, $160^{\circ}C$ for 40 min), and frying process (FP, $180^{\circ}C$ for 30 sec). The total bacterial population of the crickets was 5~7 log CFU/g, but Coliform and E. coli were not detected. The major fatty acids in all the samples were palmitic acid (C16:0), oleic acid (C18:1), and linoleic acid (C18:2). The level of polyunsaturated fatty acids was highest (63.55 g/100 g) in the LP-processed crickets. As for the amino acid content, the glutamic acid level was highest in all the samples, and the RP and FP decreased by 12.01% and 53.88%, respectively, compared to that of the LP. The mineral contents were highest in the LP-processed crickets. Hg was detected at about 1.0 ppb in all the samples, but its level was lower than the residue tolerance level in the Korean Food Code. Such conditions should be considered to better understand the quality characteristics of crickets in food processing.

• Journal of Applied Biological Chemistry
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• v.63 no.1
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• pp.51-60
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• 2020

This study was conducted to investigate changes in pesticide residues in eggplant and lettuce during washing and cooking processes after application with azoxystrobin. Eggplant was processed with running washing, steaming, and stir-frying, and lettuce was processed with soaking washing, running washing, soaking and running washing, ultrasonic cleaning, and blanching. The limit of quantitation of GC analysis of azoxystrobin was 0.01 mg/kg and the recovery rate was 84.7-109.5%. The azoxystrobin processing factors (PFs) and reduction rates in eggplant and lettuce were calculated and the results were as follows. In the case of eggplant, the azoxystrobin PF and reduction rate of running washing were 0.29 and 71.1%, respectively, those of steaming were 0.32 and 68.0%, respectively, and those of stir-frying were 0.24 and 75.7%, respectively. In the case of lettuce, the azoxystrobin PF and reduction rate of soaking washing were 0.25, 75.3%, those of running washing were 0.61 and 38.9%, respectively, those of soaking and running washing were 0.32, 68.0%, those of ultrasonic cleaning were 0.47 and 53.1%, respectively, and those of blanching were 0.26 and 73.6%, respectively. It could be identified that pesticide residues in eggplant and lettuce can be effectively reduced through washing and cooking processes and that most of pesticide residues were removed when cooking processes were undergone after washing. Therefore, azoxystrobin PFs after washing and processing can be provided as basic data for risk assessment.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.67-73
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• 2014

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.20 no.1
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• pp.34-43
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• 2001

For 202 pesticides with maximum residue limit(MRL) in Korea, anticipated problems were identified and remedial actions were suggested. The risk index expressed as the ratio of theoretical maximum daily intake against ADI which exceeds 80% appeared in 35 pesticides. Items showing 10-fold difference between Korea and Codex MRLs appeared in 35 pesticides and 47 food commodities. In any of the 202 pesticides, nominated crops without MRL were 33 items whereas non-nominated crops with MRL were 50 items. Under the Codex system, cases of separate MRLs among raw materials and processed products were exampled. Remedial actions to minimize the above-mentioned discrepancies were suggested respectively.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.240-248
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• 1997

References on the cooking and processing losses of organophosphorus (OP) pesticides in foods were collected and analyzed to indicate that the average removal of whole pesticides being 45% in water washing, 56% in detergent washing, 91% in peeling of fruits, 5l% in blanching-boiling of vegetables, 90% in milling and processing of grains. The theoretical maximum daily intake (TMDI) calculated from the food intake and Korea maximum residue limits showed that 4 among 11 pesticides exceeded the acceptable daily intake (ADI). The estimated daily intake (EDI) calculated from the food intake and monitoring data reached 17.2% of ADI on the assumption that the toxicity of OP pesticides appears as an additive effect. The % ratio of ADI for individual pesticides was 6.1% in diazinon, 5.8% in fenthion, 3.3% in fenitrothion and very low in other pesticides. By applying reduction factors to the EDI, the removal ratio of OP pesticides in cooking and processing appears to be over 50%. In summary, the exposure level of Korean population toward whole OP pesticides was estimated to reach 23% of ADI, which would not cause any health rick as yet, but calls for a systematic risk assessment.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.317-322
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• 2016

A pesticide mix solution containing difenoconazole, lambda-cyhalothrin, and lufenuron was applied 3 times on field grown chili pepper at a fivefold overdose dilution concentration of the spray solution at a pre-harvest interval of 7 day. Difenoconazole, lambda-cyhalothrin, and lufenuron were detected at 4.43, 0.334, and 1.56 mg/kg, respectively, in raw chili pepper. Washing with water reduced the residue levels to 91.4, 94.3, and 85.3%, respectively. In dried chili pepper, the residues of difenoconazole, lambda-cyhalothrin, and lufenuron were 22.2 mg/kg (processing factor, Pf =5.01), 1.65 mg/kg (Pf =4.94), and 6.54 mg/kg (Pf =4.19). In the seeds, difenoconazole and lambda-cyhalothrin were not detected, and lufenuron was detected at 0.0075 mg/kg (n=1) and <0.005 mg/kg (n=2). Thus the pesticide residues in the seeds was negligible. In the seed oil, difenoconazole and lufenuron residues were 0.0263 and 0.0295 mg/kg, respectively (concentration factors=5.26 and 4.72). These concentration factors supported the theoretical concentration factor of 6.8, assuming that all of compound present in the seed are transferred into the oil.