• Korean Journal of Agricultural Science
• /
• v.24 no.1
• /
• pp.94-107
• /
• 1997

Producing organic farm products is one of the high-payoff farming practices considering the rapid increase of consumer's purchasing power. The purpose of this study is to identify the optimal organic farming system in relation to farm income. To cope with the above objectives, present farming conditions and profitability of 15 farmers producing organic products including rice and leaf vegetables as lettuse and cabbage were surveyed in Hongsung and Ahsan Gun, Chungnam Province. Based on the surveyed data, maximization of organic farm income were analyzed under the constrained conditions such as limited monthly labour inputs and competitive use of land by Linear Programming Model. The results of this study can be summarized as follows. 1. In the profitability analysis of 15 farmers producing organic products, rice farmers could earn their farm income more than that of conventional farmers by 50%. On the other hand, the controlled lettuce farmers could get more about 100% than that of it. But the controlled cabbage farm could get more about 40% of it. These organic farm products were saled at high prices comparing with the prices of conventional farm products by 170% ~ 230% even though the crop yields produced by organic materials had decreased. 2. According to the labor requirement of the organically produced crops, rice cultivation was needed more labour inputs than the conventional farming method by 130%. On the other hand lettuce and cabbage could saved labour requirement by 40% and 80% of those respectively. Especially for the rice cultivation concern, higher labor requirement was due to the activities as organic fertilization, soil preparation and pest and weed controll, etc. 3. With the surveyed data from farmers who produced farm commodities, L.P. analysis was implemented to find out the optimul farming system and the maximum income. According to the results of L.P. analysis, 58% of total farm income could get more than the conventional farming system In the case of rice cultivation, one ha of paddy was recommendable to save more labour inputs than the controlled leaf vegetables such as lettuse and cabbage. However, in the controlled leaf vegatables, only 73% of total upland equivalent to 0.3 ha should be cultivated under the condition of labor shortage as the restricted 4 workers. And increasing the size of hogs raising should be recommened to achieve self-sufficiency of organic fertilizer. As pointed out the possibility of organic farming, present farmers producing organic farm products could be able to maximize their income by expanding organic farm size with regard to all conditions of our organic industry. Of course, there are many difficulties in the course of developing organic agriculture. So Government should effort to support the development of our organic agriculture considering the various aspects of production, marketing, Quality certification of organic produces.

• Korean Journal of Environmental Agriculture
• /
• v.32 no.3
• /
• pp.207-213
• /
• 2013

BACKGROUND: This study was conducted to develop analytical method with reproducibility, accuracy and applicability to agricultural products than the existing methods. METHODS AND RESULTS: Mean recoveries of thidiazuron ranged from 89.2 to 91.2 in hulled rices, 87.2 to 92.1 in peppers, from 76.4 to 86.9 in potatoes, from 91.2 to 95.7 in watermelons, from 86.5 to 88.5 in kiwi fruits, and from 89.5 to 94.0 in grapes, with less than 10% of relative standard deviations. In addition, the limit of quantitation was set to be 0.05 mg/kg and there were no interfering peaks in integrating the thidiazuron peak. CONCLUSION(S): These results represent that the enhanced analytical method has reliable accuracy, precision, selectivity, and sensitivity.

• Applied Biological Chemistry
• /
• v.46 no.4
• /
• pp.361-366
• /
• 2003

Anti-aflatoxigenic studies on synthetic pyridione alkaloids were conducted. Seven derivatives using piperlongumine as a leading compound were prepared from 3,4,5-trimethoxycinnamic acid (TMCA). These derivatives were analyzed for their structural confrmation and purity by HPLC, GC, GC/MS and $1^H-NMR$. 1-piperidin-1-yl-3-(3,4,5-trimethoxyphenyl)propenone (1) reaction with piperidine; 1-morpholin-4-yl-3-(3,4,5-trimethoypenyl)propenone (2) with morpholine; 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)propenone (3) with 3,5-dimethylpiperdine; 1-(2-methylpiperidine-1-yl)-3-(3,4,5-trimethoxyphenyl)propenone (4) with 2-methylpiperidine; 1-(3-hydroxypiperidin-1-yl)-3- (3,4,5-trimethoxyphenyl)propenone (5) with 3-hydroxypiperidine hydrochloride; 1-[3- (3,4,5-trimethoxyphenyl)acryloyl]piperidin-2-one (6) with ${\delta}-valerolactam;\; and\;ethyl\;1-[3-(3,4,5-trimethoxyphenyl)acyloyl]piperidine-4-carboxylate$ (7) with ethyl isonipectotate were synthesized respectively. All derivatives showed an inhibitory activity on aflatoxin $B_1$ production. In conclusion, we believe that they might be an agent for the control of mycotoxin in agricultural commodities.

• The Korean Journal of Pesticide Science
• /
• v.17 no.2
• /
• pp.84-93
• /
• 2013

Validated analytical methods for isopyrazam are meager or lacking. In the present study, a single residual analytical method was developed for isopyrazam in selected commodities. Isopyrazam was analyzed in brown rice, soybean, green pepper, mandarin, cucumber, and Korean melon. We tried different solvents and methods through extraction, partition and purification steps to obtain best analytical results. For isopyrazam samples were extracted with acetonitrile, concentrated and partitioned with n-hexane, clean-up using florisil with n-hexane/ethylacetate (70/30) and analyzed with HPLC/UVD. The limit of quantitation (LOQ) for isopyrazam was 1.0 ng (S/N > 10) and method LOQ (MLOQ) was 0.04 mg $kg^{-1}$. Recovery ranged through 81.0~105.3% (syn-isomer) and 80.8~105.6% (anti-isomer) at fortification level of 0.04 (MLOQ), 0.4 (10 ${\times}$ MLOQ), and 2.0 (50 ${\times}$ MLOQ). The coefficient of variation (CV) for isopyrazam was less than 10% regardless of sample types. These results were further confirmed with LC/MS, respectively. The proposed method is highly reproducible and sensitive and is suitable for routine analysis.

• Journal of Food Hygiene and Safety
• /
• v.5 no.3
• /
• pp.131-138
• /
• 1990

Aflatoxins is a chemically diverse group of toxic secondary metabolites that are produced by fungi and often occur in agricultural commodities. Because of their wide range of toxic effects, Aflatoxins cause severe economic losses to farmers and livestock producers and pose a health to human consuming contaminated foods. Long term prospects for biotechnological control of Aflatoxins require elucidation of the specific steps and regulation of their biosynthetic pathways . Aflatoxin determinations can be approached many ways. It is essential to safely handle all experimental materials associated with aflatoxin analysis or aflatoxigenic fungi Visual screening of suspect samples, base on the presence of conidial head of the aspergillus flavus group, and screening samples for the presence of bright greenish yellow flourescence are not chemical tests and such screening techniques may allow aflactoxin contaminated lots into commerce. Microcolumn screening procedures should always be used in conjunction with a quantitative method. Several thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) methods are suitable for quantitation and are in general use. Immunochemical Methods such as the ELISA or affinity column chromatography methods are being rapidly developed. The chemical and immunochemical methods can be reliable if care is taken, using suitable controls and personnel that are well trained . All analytical laboratories should stress safety and include suitable analytical validation procedure. Especially a worldwide enquiry was undertaken in recent to obtain up-to-date information about aflatoxin legislation in as many countries of the world as possible. The information concerns aflatoxin in foodstuffs. aflatoxin MI in dairy products, aflatoxins in animal feedstuffs. Limits and regulations for aflatoxin have been expended in recent with more countries having legislation on subject, more products, and more aflatoxins covered by this legislation.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.1
• /
• pp.21-28
• /
• 2001

Enzyme linked-immunosorbent assay (ELISA) for a rapid detection of fungi, Aspergillus and Penicillium genera in food, were developed and their efficiencies were approved by detecting artificially contaminated agricultural commodities. Mice were immunized with partially purified Aspergillus flavus extracellualr polysaccharide (EPS) and lymph node cells of the mice were fused with the myeloma cells for production of monoclonal antibodies. Mab 1G11, one of the antibodies, was selected and purified. A sandwich ELISA was established and its detection limit toward A. flavus EPS was 1mg/ml. Among the 59 strains tested (including 18 species of Aspergillus, 16 of Penicillium, 11 of Fusarium, 1 of Absidia, 2 of Alternaria, 2 of Candida, 2 of Cladosporium, 2 of Geotrichum, 2 of Mucor, 2 of Rhizopus, 1 of Trichoderma), species of Aspergillus and penicillium had a high reactivity with Mab 1G11 even up to 10,000 times dilution of culture broths. The other genera except Cladosporium resinae showed no reactivity, thus Mab 1G11 was specific to the genera of Aspergillus and Penicillium. The epitope of A. flavus EPS against monoclonal Mab 1G11 was on the carbohydrate moiety when 1 to 100$\mu g/g$ A. flavus EPS were put into rice, potato, and mandarin orange, the average recoveries detected by sandwich ELIA were 123, 59, and 76%, respectively. Correlation was found to be linear between the EPS, and mycelium of A. flavus and Penicillium citrinum grown in a liquid medium (r=0.87 and 0.96), and also between the EPS and colony forming unit in solid media of rice of potato (r=0.91-0.99).

• The Korean Journal of Pesticide Science
• /
• v.4 no.4
• /
• pp.1-11
• /
• 2000

Since the chemical pesticides have been played a major role in crop protection practices during last 5 to 7 decades, social concerns on the pesticide residues in and on food commodities as well as environmental compartments have also growing with endless demands and interests. Most national regulation authorities over the world have paid a special attention on the data requirements for pesticide registration. In addition, even the registered pesticides also should follow the re-registration process, which meets today's guidelines and regulatory triggers and safety profiles. More recently, a defined interest in the international bodies has given to the global conservation program from the environmental contamination; these involves persistent organic pollutants (POPs), endocrine disrupting chemicals (EDs), biocides, etc.. In order to secure the food safety and keep our circumference sound, in-depth efforts getting information from global networks have perpetually to be given under relevant national agencies. At the same time, a nation-wide survey of the residues has also to be in operation to monitor the tendency of the toxicant in/on foods, feeds, and environmental segments. In final, the scientifically assessed results on safety should be opened to the public to provide the right-to-know for the consumers.

• Journal of the Economic Geographical Society of Korea
• /
• v.21 no.2
• /
• pp.90-106
• /
• 2018

This study suggests a gateway strategy for transporting agri-food exports to expand exports after examining the patterns of Korean agri-food exports by commodities and the role of export gateways. Korean agri-food exports have increased, but processed food exports have increased significantly compared to fresh agricultural products during the last 17 years. More importantly, Busan port is the main agri-food export hub in Korea. Under these circumstances, this paper examines the determinants of processed cereal-based food (HS 19) exports through Busan port using classification and regression tree (CART) analysis. As a result, the main factors that help to predict the real value of Korean exports are the GDP of the export destination countries, their distances from Korea and their GNI per capita. The destinations of Korean agri-food exports are finally classified into eight groups, which reveals the characteristics of clusters and provides useful insights for the strategies to expand agri-food exports.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.187-187
• /
• 2003

To examine the effect of packaging method on strawberry, tomato, and plum quality, the rate of weight loss, Hunter a value, decay rate, anthocyanin contents, and microbial (total bacterial counts, mold and yeast, and pseudomonas) changes were determined during storage. Strawberry was packaged with low density polyethylene (LDPE). Tomato and plum were packaged with high density polyethylene film (HDPE). Strawberries, tomatoes, and plums were then stored at 4$^{\circ}C$ and 20$^{\circ}C$, respectively. LDPE package was the most effective on the decrease of decay rate of strawberry and the rate of weight loss for packaged strawberry was lower than that of the non-packaged. HDPE package was the most effective on the rate of weight loss during storage of tomatoes and plums regardless of storage temperature. Hunter a value increased during storage. Anthocyanin contents of plums increased overall with increasing storage time, and plums stored without package were changed more than those with package. Microbial changes of strawberry, tomato, and plum stored at 4$^{\circ}C$ and 20$^{\circ}C$ were monitored during storage. Packaging method did not affect the microbial change, yet temperature did affect the microbial change significantly. These results indicate that storage of these commodities at 4$^{\circ}C$ should be recommended in terms ,of microbial safety as well as quality and shelf-life.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.2
• /
• pp.142-147
• /
• 2021

BACKGROUND: Agricultural use and pest control purposes of pesticides may lead to livestock products contamination. Thiodicarb and its degraded product, methomyl, are carbamate insecticides that protect soya bean, maize, fruit, and vegetables and control flies in animal and poultry farms. For maximum residue limit enforcement and monitoring, the JMPR residue definition of thiodicarb in animal products is the sum of thiodicarb and methomyl, expressed as methomyl. This residue definition was set to consider the fact that thiodicarb was readily degraded to methomyl in animal commodities. And therefore the simultaneous analytical method of thiodicarb and methomyl is required for monitoring in livestock products. METHODS AND RESULTS: The study was conducted using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and HPLC-MS/MS to determine the thiodicarb and methomyl in livestock products. The limit of quantitation (LOQ) was 0.01 mg/kg for livestock products, including beef, pork, chicken, milk, and egg. The coefficient of determinations (r²) for the calibration curve were > 0.99, which was acceptable values for linearity. Average recoveries at spiked levels (LOQ, 10LOQ, and 50LOQ, n=5) in triplicate ranged from 73.2% to 102.1% and relative standard deviations (RSDs) were less than 10% in all matrices. CONCLUSION: The analytical method was validated for the performance parameters (specificity, linearity, accuracy, and precision) in livestock products to be acceptable by the CODEX guidelines.