• Horticultural Science & Technology
• /
• v.34 no.1
• /
• pp.183-194
• /
• 2016

This experiment was conducted to establish an official determination method to measure fluazinam residue in horticultural crops for import and export using GC-ECD/MS. Fluazinam residue was extracted with acetone from fresh samples of four representative horticultural products, the vegetable crops green pepper and kimchi cabbage, and the fruit crops mandarin and apple. The acetone extract was diluted with saline water and n -hexane partitioning was used to recover fluazinam from the aqueous phase. Florisil column chromatography was additionally employed for final purification of the extract. Fluazinam was separated and quantitated by GC with ECD using a DB-17 capillary column. The horticultural crops were fortified with three different concentrations of fluazinam. Mean recoveries ranged from 82.5% to 99.9% in the four crops. The coefficients of variation were less than 10.0%. The quantitative limit of fluazinam detection was $0.004mg{\cdot}kg^{-1}$ in the four crop samples. GC/MS with selected-ion monitoring was also used to confirm the suspected residue. This analytical method was reproducible and sensitive enough to measure the residue of fluazinam in horticultural commodities for import and export.

• Journal of Ginseng Research
• /
• v.4 no.1
• /
• pp.1-7
• /
• 1980

In order to establish effective extracting method of ginseng extracts from fresh ginseng, the yield, chemical composition, physical properties and organoleptic quality of the extracts, which are extracted with various concentrations of ethanol, were investigated. The results are as follows : 1. The yield of the extracts was increased with decreasing the concentration of ethanol as solvent. As in case of water as a solvents, the highest yield was achieved when 23.64% of water was used. The yield were 12.3% and 9.05%, when 70% and 90% of ethanol were used, respectively lively. 2. Crude protein content is the highest level and nitrogen·free extracts content is the lowest at the concentration of 50% ethanol. Lipid was increased linerly while ash was decreased as increment of ethanol concentration. 3. Viscosity and residue of the extracts also decreased in accordance with the increament of ethanol concentration and the transmittance value and pH of extract solutions were almost similar except transmittance value of the water extracts. 4. The extracts extracted with 70% ethanol gave the best result of sensory test. The total sensory test score of each extracts (70%, 90%, 50%, 0% and 30%) were 70, 65, 50, 46 and 41, respectively.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.4
• /
• pp.63-73
• /
• 2015

This study was carried out to evaluate the change of heating value of cow manure by applying pre-treatment process. Three types of treatment precess; Composting, Dry anaerobic digestion and Physical compression were applied as a pre-treatment method. Composting and anaerobic digestion of cow manure were cause of caloric value reduction of the cow manure. The heating value of cured compost was 5% lower than that of initial composting material. The heating value of dry anaerobic digestion residue was 25.7% lower than that of fresh cow manure. By physical compression of cow manure, heating value and VS/TS ratio (Volatile solids/Total solids ratio) of compressed cow manure were higher than that of fresh cow manure. On the other hand, heating value and VS/TS ratio of leachate generated by compression process were lower than those of fresh cow manure.

• The Korean Journal of Pesticide Science
• /
• v.16 no.3
• /
• pp.217-221
• /
• 2012

This study was carried out to evaluate residual characteristics of tolclofos-methyl in ginseng and elucidate the reason for its high detection rate from fresh ginseng selling at markets. Seeds of ginseng were sowed after seed dressing with tolclofos-methyl and after a year of growth, the young seedlings were transplanted to field. They were then harvested annually until three-years of growth and the pesticide residue was analyzed in them. LOD and LOQ of the pesticide were 0.001 and 0.003 mg/kg, respectively. Recovery test was carried out to validate the analytical method for tolclofos-methyl in ginseng. The ginseng seedlings were fortified with the test pesticide at the level of LOQ, ten times of LOQ and maximum residue concentration of tolclofos-methyl. Its recovery ranged from 77.37 to 100.16%. Residual concentration of tolclofos-methyl in ginseng seedlings just before transplanting and two-year-old ginseng were from 7.58 to 8.05 and from 6.46 to 6.79 mg/kg, respectively. In case of three-year-old ginseng, it was found to be from 4.18 to 4.35 mg/kg. As a result of annual pesticide residue analysis, concentration of the pesticide was found to decrease time-coursely in ginseng. This may be due to decomposition and increasing of fresh weight of the ginseng during the cultivation periods of three years.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.3
• /
• pp.248-254
• /
• 2012

BACKGROUND: In order to elucidate residual characteristics of difenoconazole and thiamethoxam by treatment to sweet persimmons for one year and to generate the data for the maximum residue limit (MRL) establishment for those pesticides in or on sweet persimmon. METHODS AND RESULTS: Systemic fungicide difenoconazole WP (10% a.i.) and systemic insecticide thiamethoxam WG (10% a.i.) were sprayed onto 12~25-years-old sweet persimmons according to its preharvest interval (PHI), respectively, and then fresh sweet persimmons were harvested at 0, 1, 3, 7, 14, 21 days after treatment from pesticide-sprayed plots at each 3 sites. The analytical methods were evaluated to limit of quantification, linearity, specificity, reproducibility and recoveries. The crop samples were extracted with acetone and performed dichloromethane partition process. The extracted samples of difenoconazole were analyzed by GC-ECD and the thiamethoxam extracted samples were analyzed by HPLC with good sensitivity and selectivity of the method. The average recoveries of difenoconazole ranged from 87.5 to 99.5% with the percentage of coefficient variation in the range 4.1~7.6% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg). And the average recoveries of thiamethoxam and clothianidin ranged from 88.8 to 98.9% and 83.2 to 96.6% with the percentage of coefficient variation in the range 3.6~5.0% and 3.8~9.4% at three different spiking levels(0.02, 0.2 and 2.0 mg/kg), respectively. The residue amounts ranges of difenoconazole were 0.2~0.56 mg/kg and the residue amount was decreased below the MRL level, 1.0 mg/kg, after 1 day harvest. The residue amounts ranges of thiamethoxam were 0.08~0.28 mg/kg and the residue amount was decreased below the MRL level, 0.5 mg/kg, after 1 day harvest. And the residue amount of clothianidin was below then 0.03 mg/kg for only one test site of 14 and 28 day samples. CONCLUSION: As a result, the residual amounts of difenoconazole and thiamethoxam were not exceeded the MRL of established criteria for sweet persimmon. The biological half-lives of difenoconazole and thiamethoxam were 13.6, 19.4, 16.3 and 10.0, 15.3, 14.0 days at each three test sites, respectively.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.23-29
• /
• 2016

This study was carried out to survey residual characteristics of pesticide in fresh ginsengs collected from 45 markets at 15 regions in Korea using multiresidue analysis with a GC-MS/MS and an LC-MS/MS. After residue analysis was performed, the pesticides detected from ginsengs were quantitated using their analytical methods validated by recovery tests with a GC-ECD/NPD. As a results of analysis of pesticide residue, cypermethrin, fenitrothion, fludioxonil, thifluzamide, and tolclofos-methyl were detected from 16 samples among 45 samples in total, indicating detection rate was 35.6%. Tolclofos-methyl was found to be highest in detection frequency in ginseng. Fenitrothion that has not established maximum residue limit and pre-harvest interval for ginseng was detected. The amounts of all pesticides detected were less than their MRLs. Ratios of estimated daily intakes to acceptable daily intakes of the detected pesticides in ginseng were found to be from 0.03 to 16.67%.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.1
• /
• pp.100-110
• /
• 2020

Objective: The objective of this study was to isolate proteolytic microorganisms and evaluate their effects on proteolysis in total mixed ration (TMR) silages of soybean curd residue. Methods: TMRs were formulated with soybean curd residue, alfalfa or Leymus chinensis hay, corn meal, soybean meal, a vitamin-mineral supplement, and salt in a ratio of 25.0: 40.0:30.0:4.0:0.5:0.5, respectively, on a basis of dry matter. The microbial proteinases during ensiling were characterized, the dominate strains associated with proteolysis were identified, and their enzymatic characterization were evaluated in alfalfa (A-TMR) and Leymus chinensis (L-TMR) TMR silages containing soybean curd residue. Results: Both A-TMR and L-TMR silages were well preserved, with low pH and high lactic acid concentrations. The aerobic bacteria and yeast counts in both TMR silages decreased to about 10⁵ cfu/g fresh matter (FM) and below the detection limit, respectively. The lactic acid bacteria count increased to 10⁹ cfu/g FM. The total microbial proteinases activities reached their maximums during the early ensiling stage and then reduced in both TMR silages with fermentation prolonged. Metalloproteinase was the main proteinase when the total proteinases activities reached their maximums, and when ensiling terminated, metallo and serine proteinases played equally important parts in proteolysis in both TMR silages. Strains in the genera Curtobacterium and Paenibacillus were identified as the most dominant proteolytic bacteria in A-TMR and L-TMR, respectively, and both their proteinases were mainly with metalloproteinase characteristics. In the latter ensiling phase, Enterococcus faecium strains became the major sources of proteolytic enzymes in both TMR silages. Their proteinases were mainly of metallo and serine proteinases classes in this experiment. Conclusion: Proteolytic aerobic bacteria were substituted by proteolytic lactic acid bacteria during ensiling, and the microbial serine and metallo proteinases in these strains played leading roles in proteolysis in TMR silages.

• Korean Journal of Weed Science
• /
• v.15 no.2
• /
• pp.121-130
• /
• 1995

Greenhouse and laboratory studies were conducted to investigate allelopathic potential of some weed species on alfalfa(Medicago sativa L.) germination and seedling growth. In the comparison between top(leaves+stems) and root extracts, top extract exhibited greater allelopathic effects on alfalfa germination than that of root. The various weed species extract differently responded to alfalfa test species, WL-320, in terms of allelopathic effect. Top and root aqueous extracts of lambsquarter(Chenopodium album L.), giant foxtail(Setaria faberii Herrm.), redroot pigweed (Amaranthus retroflexus L.), velvetleaf(Abutilon theophrasti Medic.), crabgrass(Digitaria sanguinalis L.), canada thistle(Cirsium arvense L.) and prostrate knotweed(Polygonium aviculare L.) significantly inhibited germination, seedling length, weight, vigor, and rate of germination of alfalfa. The regression slopes of various top extracts showed that velvetleaf(b=3.69) extracts were the most inhibitory, while large crabgrass(b=2.39) extracts had the least allelopathic effect on alfalfa germination. Germination, seedling length and weight of alfalfa were inversely proportional to the concentration of dried velvetleaf extracts. Also, more of the toxic effects were observed from the dried extracts compared to the fresh extracts. Residue of velvetleaf inhibited significantly alfalfa emergence and survival percentage compared to the control. The emergence and survival percentage of alfalfa were 44%, 57% at 1.0% residue treatment, respectively. When weed residues were mixed with silica sand with incubation time, velvetleaf residue most inhibited alfalfa growth. The degree of inhibition increased as incubation time increased. An incubation for 72h caused the greatest inhibition of alfalfa growth. These results demonstrate the different allelopathic activity of weed species extracts on alfalfa and suggest that weed may affect alfalfa growth and development through the inhibitory effects of allelochemicals present in weed tissue.

• Korean Journal of Pharmacognosy
• /
• v.8 no.3
• /
• pp.121-124
• /
• 1977

Aspidium ether extract was obtained from Dryopteris crassirhizoma(Aspidiaceae), which is widely distributed in Korea and its vermicidal effect on the rats infected with Hymenolepis diminuta was investigated. Effects of Aspidium ether extract purchased from the market, several fractions obtained from the seed of Torreya nucifora and bithionol were also compared. Vermicidal effect of Aspidium against Hymenolepis diminuta was found only in one-third of the rats used for investigation and the effect of the fresh Aspidium ether extract was similar to that of Aspidium ether extract purchased from market. However, it was observed that the whole seeds of Torreya nucifera (Torreyaceae) and its residue from which oil fraction was removed as well as bithionol were highly effective against Hymenolepis diminuta.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.4
• /
• pp.687-692
• /
• 1998

To use onion(Allium cepa L.) residue as raw materials of food product, yields of onion-juice according to various extracting methods and optimal extracting condition of quercetin and its related glycosides were carried out. Onion juices gained by the methods of pressing, rotary crushing, freeze pressing and enzyme treatment. The yield by the method of enzyme treatment was higher than others. The yields of juice from fresh onion and heat-treated onion(8$0^{\circ}C$/10min) by pressing were 66% and 83%, respectively. Ethanol extraction of onion was efficient at 75$^{\circ}C$ and acetic acid extraction was proper at 3% concentration for 3 hours at 11$0^{\circ}C$. The onion extract was fractionated in the order of hexane, chloroform, ethylacetate and butanol to test flavonoids. The highest abundant flavonoids were found in ethylacetate and butanol fraction.