• Analytical Science and Technology
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• v.37 no.1
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• pp.1-11
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• 2024

In agricultural households cultivating vegetables and fruits, the use of various pesticides to protect crops from diseases and pests or to control weeds is widely practiced enhancing quality and productivity. However, pesticides can pose a threat to consumer health by remaining on the food surface or migrating into the food interior. Households commonly peel off skins, wash with water, or use chemical methods to remove foreign substances including residual pesticides on the food surface. In this study, we measured the washing rate by comparing the pesticide concentrations before and after washing in the leafy vegetable perilla leaves and the fruits strawberries and apples, which were intentionally exposed to pesticides. We compared washing rates using tap water, a baking soda solution, and a commercially available food-specific cleaning solution. The target pesticides for analysis were azoxystrobin, bifenthrin, boscalid, difenoconazole, flubendiamide, and indoxacarb, and the residual pesticide analysis was performed using GC-MS/MS or LC-MS/MS. The removal rates of pesticides were highest with the food-specific cleaner, followed by baking soda and tap water in order.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.314-321
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• 2007

This study was conducted to select leaf vegetables suitable for cultivation in apartment verandas and simple and easy fertigation method for home gardening. In order to develop the convenient fertigation method, hydroponics, wick irrigation, and overhead irrigation methods were compared. For the wick irrigation, two types of nutrient sources were used; one was slow release fertilizers mixed with medium and the other one was nutrient solution filled in container located under pots. The growth of leafy lettuce, leaf mustard, and leaf beet was better in both of the wick irrigation methods rather than in overhead irrigation and hydroponics. The wick irrigation method is very easy, so that it is expected to bring a good result from the cultivating and managing point of view, if it brings with commercialized system along with slow release fertilizer. As a result of investigation of environment such as temperature, relative humidity, and irradiance level in apartment verandas in autumn the highest irradiance level during a day was just 48% and 35% in verandas facing south and feeing southeast, respectively, comparing to that in greenhouse. The light environment was investigated as a limiting factor for vegetable growing in verandas. Therefore, to select the vegetables showing good growth under low irradiance environment, nine leaf vegetables such as romaine lettuce, lent lettuce, head lettuce, endive, pak-choi, leaf mustard, garland chrysanthemum, leaf beet, and Chinese chive were grown under 0%, 50%, 70%, 90% shading. Among them, Chinese chive showed the best growth under low irradiance levels. Endive showed line growth reduction according to shading degree, however, even under 90% shading condition, it showed good growth. And then leafy lettuce, garland chrysanthemum, and pak-choi followed. Therefore, these results will be of help in selecting vegetables for veranda gardening with different light levels.

• Rapid Communication in Photoscience
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• v.3 no.1
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• pp.25-27
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• 2014

The relative importance of radiation dose, storage time, and temperature in radiation processing of spinach (Spinacia oleracea L.), was evaluated in terms of the postharvest quality through a model study using leaf disks. Physiological activity and chlorophyll and carotenoid contents were measured to represent the postharvest quality (in terms of external appearance) of spinach, a leafy green vegetable. At $22^{\circ}C$ and $30^{\circ}C$, the higher gamma-radiation dose caused a greater decrease in the physiological activity, depending on the storage time of 4 d. However, this decrease was not significant at $4^{\circ}C$ and $15^{\circ}C$. Total chlorophyll and carotenoid contents were substantially decreased by 3 kGy at $15^{\circ}C$, and dose-dependently by 0.5-3 kGy at $22^{\circ}C$. In contrast, the proportion of lutein in total carotenoid was significantly increased in the 2-3-kGy samples only at $22^{\circ}C$, while that of ${\beta}$-carotene was slightly decreased, indicating progression of leaf aging. These data suggest that the unfavorable effect of gamma irradiation on the postharvest quality of spinach could be avoided or controlled by the storage time or temperature rather than the radiation dose. The current study could be available to improve radiation processing of other leafy green vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.492-500
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• 1999

The aim of this study was to assess the association between total vitamin A, retinol and carotene intakes and serum concentration of total carotenoids in Korean male smokers and nonsmokers. Food frequency and nutrient intakes of 64 healthy college students were estimated by the 24 hour recall method and food frequency questionnaire and analyzed by smoking status. Serum total cartenoids and lipid profiles were measured in 28 smokers and 36 nonsmokers. The mean total vitamin A, retinol and carotene intakes of smokers were not significantly different from nonsmokers. However, carotene intakes of the smokers who have smoked more than 5 packyears were significantly lower than those of nonsmokers. Smokers consumed green yellow leafy vegetables more often(P=0.005) and fresh fruits less often(P=0.017) than nonsmokers. The serum total carotenoids of smokers consuming the same amount of retinol and carotene as nonsmokers, 1.79 g/ml, were 17% lower than nonsmokers, 2.15 g/ml(P<0.05). The lipid profiles including total cholesterol, LDL cholesterol, VLDL cholesterol and triglycerides of smokers were not significantly different from nonsmokers, however, the concentration of HDL cholesterol of smokers were significantly higher than that of nonsmokers. The serum carotenoids concentration was positively associated with fruit consumption frequency in smokers, and also was positively associated with green yellow leafy vegetable consumption frequency in non smokers. There were no correlations between dietary and serum carotenoids for smokers as well as nonsmokers. It was concluded that smoking could be inversely related to the serum concentration of carotenoids at constant carotene intakes and smokers might require more carotene to reach the same concentration comparable to nonsmokers.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.237-243
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• 2013

Pesticides were sprayed on perilla leaf and leafy lettuce in a greenhouse and the reduction rate of pesticide residues on each vegetable by washing were tested. The reduction rate of pesticide residues by washing for 30 sec~3 min on perilla leaf were 3~63% in tap water, 2~58% in salt water, 6~74% in green tea water, and 8~86% in detergent solution. The detergent solution only showed significant difference in reduction rates compared to the tab water washing. Considering reduction effects of the washing duration, it was showed that the reduction rates were a pattern of inclining as the duration of washing process increased, but there was no significant difference in the reduction rates except the reduction rates between washing in the detergent solution for 1 min and 3 min. Comparing washing in flowing tab water and in stagnant tab water with leafy lettuce, the reduction rate by one time washing were 8~68% in flowing tab water and 7~64% in stagnant tab water. The water and the time used in this experiment were 17.5 L, 2.9 min with flowing tab water and 4 L, 1 min with stagnant tab water. The reduction rate by 3 times washing in stagnant tab water were 16.5~76.6%, and the water and the time used were 12 L, 3 min. Therefore, when the water and the time used to wash vegetables were considered, washing two or three times in stagnant tab water could be more effective than washing one time in flowing tab water.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.963-974
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• 2015

This study was conducted to determine the effects of organic vegetable cultivation on the soil physical properties in 33 farmlands under plastic greenhouse in Korea. We were investigated 5~8 farms per organic vegetable crops during the period from August to November 2014. The main cultivated vegetables were leafy lettuce (Lactuca sativa L.), Perilla leaves (Perilla frutescens var. Japonica Hara), cucumber (Cucumis sativus L.), strawberry (Fragaria ananassa L.) and tomato (Lycopersicon spp.). We have analyzed soil physical properties. The measured soil physical parameters were soil plough layer, soil hardness, penetration resistance, three soil phase, bulk density and Porosity. The measurement of the soil plough layer, soil hardness and penetration resistance were carried out direct in the fields, and the samples for other parameters were taken using the soil core method with approximately 20 mm diameter core collected from each organic vegetable field. Soil plough layer was average 36 cm and ranged between 30 and 50 cm, and slightly different depending on the sorts of vegetable cultivation. The soil hardness was $0.17{\pm}0.15{\sim}1.34{\pm}1.02$ in the topsoil, $0.55{\pm}0.34{\sim}1.15{\pm}0.62$ in the subsoil. It was not different between topsoil and subsoil, but showed a statistically significant difference between the leafy and fruit vegetables. Penetrometer resistance is one of the important soil physical properties that can determine both root elongation and yield. The increase in density under leafy vegetables resulted in a higher soil penetrometer resistance. Soil is a three-component system comprised of solid, liquid, and gas phases distributed in a complex geometry that creates large solidliquid, liquid-gas, and gas-solid interfacial areas. The three soil phases were dynamic and typically changed in organic vegetable soils under greenhouse. Porosity was characterized as range of $54.2{\pm}2.2{\sim}60.3{\pm}2.4%$. Most measured soils have bulk densities between 1.0 and $1.6gcm^{-3}$. To summarize the above results, Soil plough layer has been deepened in organic vegetable cultivation soils. Solid hardness (the hardness of the soil) and bulk density (suitable for the soil unit mass) have been lowered. Porosity (soil spatial content) was high such as a well known in organic farmlands. Important changes were observed in the physical properties according to the different vegetable cultivation. We have demonstrated that the physical properties of organic cultivated soils under plastic greenhouse were improved in the results of this study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.3
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• pp.286-293
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• 1986

The purpose of this study was to investigate the effect of withering on mechanical properties for optimizing the condition of transportation and storage of fresh leafy vegetables which they would be easily able to be suffered the physical damage. Experimental material used were spinaches and leeks which were easily apt to be withered. The breaking stress, elastic modulus and viscosity were measured in the range of temperature $3{\sim}37^{\circ}C$ and water content $70{\sim}95%$ by the four element model, being used the creep tester made by author. As a result of this study, while water content was decreased, breaking stress was increased. The elastic modulus and viscosity of the specimens were not influenced on temperature, but on water content. In reversibility test of the withering, the appearance, water content and elastic modulus of the specimens were completely recovered to the initial freshness, but the viscosity was not.

• Korean Journal of Environmental Agriculture
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• v.30 no.4
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• pp.440-445
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• 2011

BACKGROUND: This study was conducted to monitor the current status of pesticide residues and to assess their risk in domestic agricultural products. The samples were rice, barley, lettuce and perilla leaf. These four types of agricultural products were those with GAP(Good Agricultural Practice) certification, organic agricultural products, pesticide-free agricultural products or general agricultural products. METHODS AND RESULTS: They were purchased from traditional markets and supermarkets of 12 regions in Korea from July to August 2010. The total number of samples was 259 for agricultural products and these were analyzed by GC/ECD, GC/NPD and GC/MSD. We used multiresidue methods to analyze for 110 different pesticides except for herbicides. CONCLUSION: In this study, residual pesticides were detected in 18 samples. Among these general agricultural products, organic agricultural products and products with GAP-certification were detected in 12, 4 and 2 samples, respectively. Detection rates of general agricultural products, organic agricultural products and products with GAPcertification were 4.6%, 1.5% and 0.8% respectively. Pesticides were not detected in pesticide-free agricultural products. Their detection levels were less than their maximum residue levels. Their estimated daily intakes ranged from 0.0003% to 0.04302% of their acceptable daily intakes, of which the values have no effect on human health.

• Food Science and Preservation
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• v.16 no.4
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• pp.573-578
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• 2009

Microbial contamination levels in a fresh-cut leafy vegetable processing plant were evaluated. Total plate counts of samples collected from the walls, equipment, and raw materials ranged from $10^1{\sim}10^2$ CFU/100 $cm^2$, $10^0{\sim}10^4$ CFU/100 $cm^2$, and $10^4{\sim}10^6$ CFU/g, respectively. No coliforms were detected on walls; however, equipment and raw materials contained coliforms in concentrations ranging from ND (not detected)to $10^2$ CFU/100 $cm^2$ and $10^4{\sim}10^5$ CFU/g, respectively. Additionally, total plate counts for falling and floating bacteria in the processing plant were $10^0{\sim}10^1$ CFU/plate and $10^1{\sim}10^3$ $CFU/m^3$, respectively. Pathogenic microorganisms such as Escherichia coli, Salmonella spp, Staphylococcus aureus, or Listeria monocytogenes were not detected on walls, equipment, or raw materials. Overall, the results of this study indicate that hygiene control in the fresh-cut processing plant should be improved.

• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.36-47
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• 2011

This study was performed to investigate the contaminated status of endocrine disruptor-suspected pesticides in agricultural products distributed in northern Seoul in 20l0. We analyzed 33 kinds of pesticides by multiresidue analysis method in 3,081 samples. Twelve pesticidcs were detected 600 times and violated 22 times from the agricultural products. The highest frequency of detection was procymidone and that of violation was endosulfan. The highest rates of detection divided violation times as diazinon. In agricultural products, 466 samples had pesticide residues and 22 samples violated the maximum residue limits (MRLs). Agricultural products were also classified by type and red pepper powder belonged to the others was the highest detection rate at 70.7%, fruiting vegetables 35.3%, tea leaves 23.6%, stalk and stem vegetables 21.2%, fruits 14.6% and leafy vegetables 11.2%. The rates of violation sample were stalk and stem vegetables 1.1%, leafy vegetables 1.0% and roots and tubers 0.4%. Leek was to be managed primarily because it had the high detection and violation ratio and was detected together several pesticides.