• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.231-237
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• 2006

Nowadays the teabag is worldwide used for various products including green tea, tea, coffee, etc. since it is convenient for use. In case of outer packaging printed, however, there is a possibility that the plasticizers which is used for improvement in adhesiveness of printing ink may shift to inner tea bag. In this study, in order to monitor residual levels of plasticizers in teabags, we have established the simultaneous analysis method of 9 phthalates and 7 adipates plasticizers using gas chromatography (GC). These compounds were also confirmed using gas chromatography-mass spectrometry (GC-MSD). The recoveries of plasticizers analyzed by GC ranged from 82.7% to 104.6% with coefficient of variation of $0.6\sim2.7%$ and the correlation coefficients of each plasticizer was $0.9991\sim0.9999$. Therefore this simultaneous analysis method was showed excellent reproducibility and linearity. And limit of detection (LOD) and limit of quantitation (LOQ) on individual plasticizer were $0.1\sim3.5\;ppm\;and\;0.3\sim11.5\;ppm$ respectively. When 143 commercial products of teabag were monitored, no plasticizers analysed were detected in filter of teabag products. The migration into $95^{\circ}C$ water as food was also examined and the 16 plasticizers are not detected. In addition we carried out analysis of heavy metals, lead (Pb), cadmium (Cd), arsenic (As) and aluminum (Al) in teabag filters using ICP/AES. $Trace\sim23{\mu}g$ Pb per teabag and $0.6\sim1718{\mu}g$ Al per teabag were detected in materials of samples and Cd and As are detected less than LOQ (0.05 ppm). The migration levels of Pb and Al from teabag filter to $95^{\circ}C$ water were upto $11.5{\mu}g\;and\;20.8{\mu}g$ per teabag, respectively and Cd and As were not detected in exudate water of all samples. Collectively, these results suggest that there is no safety concern from using teabag filter.

• Food Science and Preservation
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• v.20 no.6
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• pp.760-765
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• 2013

The image analysis as a tool for evaluation of browning degree on fresh-cut lotus root was studied. The fresh-cut lotus root treated as 4 groups (Cont-without any treatment, DB-blanching at $50^{\circ}C$ for 5 min in distilled water, AB-blanching at $45^{\circ}C$ for 5 min in 1% ascorbic acid, CB-blanching at $45^{\circ}C$ for 5 min in 1% citric acid). The samples treated with each methods were packaged with 0.04 mm polyethylene bag ($25cm{\times}30cm$) and stored at $4^{\circ}C$ for 9 days. On the RGB color space, the AB and CB group showed high R, G, B value. On the HSV and CIE $L^*a^*b^*$ color space, the AB and CB group showed low browning area, $a^*$, $b^*$ value and high $L^*$ value. Polyphenol oxidase activity was low in the AB and CB groups in all storage period. This result means that the AB and CB groups were inhibited the development of tissue browning. The result of sensory evaluation also supported this opinion. And the correlation coefficient between sensory evaluation with all color values was over 0.84. Especially, the $L^*$ value showed the highest correlation coefficient (0.93). In conclusion, the image analysis is suitable for analysis of browning degree on fresh-cut lotus root by analyzing diverse color value.

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.224-230
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• 2013

BACKGROUND: Perchlorate(${ClO_4}^-$) is an anion that is extremely water-soluble and environmentally stable. It mostly exists in the form of sodium perchlorate, ammonium perchlorate and potassium perchlorate which are used in rocket fuels, propellants, ignitable sources, air bag inflation systems and explosives. Perchlorate can be taken into the thyroid glands and interfere with iodide uptake. The determination of perchlorate in agricultural products is important due to its potential health impact on humans. The objective of this study was to determine the perchlorate concentrations in the samples of various agricultural products and soils. METHODS AND RESULTS: In this study, samples of cereal(Rice, Barley, Corn, Bean), vegetable(Spinach, Lettuce, Sesame, Chives, Chili, Pumpkin, Tomato), fruit(Apple, Pear, Tangerine, Grape) were analyzed for perchlorate contents. Perchlorate concentrations were analyzed by liquid chromatography-tandem mass spectrometry. The results showed that agricultural products respectively contained perchlorate concentrations in the range of : cereals N.D.~$7.46{\mu}g/kg$, vegetables $0.52{\sim}23.06{\mu}g/kg$, fruits $0.19{\sim}2.66{\mu}g/kg$. Bioconcentration factor was in the order of : vegetables > cereals > fruits. Bioconcentration factor was highest follwed by Sesame 37.88, Corn 21.51, Spinach 10.57, Tangerine 4.39, Chives 2.89 and Lettuce 1.90. The recoveries of perchlorate from spiked agricultural products and soils ranged from 87.72~111.26% and 102.09~111.23%. CONCLUSION(S): The health risk assessment results obtained in this study are lower than the RfD(Reference Dose, 0.0007 mg/kg/body weight/day) value as suggested by the Integrated Risk Information System(US IRIS). Our results indicate that, people currently exposed to perchlorate from agricultural products consumption are considered as safe.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.151-157
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• 2000

This study was carried out to isolate and identify the maysin and related flavonoid analogues in corn silks. Silks were covered with silk bag to prevent pollination and were sampled at 3-5 days after silking. The silks were filled with 100% MeOH and stored at $0^{\circ}C$ until analysis. The MeOH extracts of corn silks were filtered and concentrated at 35-4$0^{\circ}C$. The ${CH}_2$${Cl}_2$ was added on the concentrated aqueous solution to remove the chlorophyll and lipids. The Cis open column (25mm$\times$54 cm) was washed and activated with serial treatment of 500$m\ell$ of 100% MeOH(twice)longrightarrow75% MeOH longrightarrow50% MeOHlongrightarrow30% MeOHlongrightarrow100% $H_2$O(2 times). The concentrated aqueous solution was applied to the $C_{18}$ column and washed with $H_2O$ several times to remove the sugars and water soluble pigments. Neochlorogenic acid, chlorogenic acid and 4-caffeoylquinic acid were eluted with 10% MeOH, and rhamosyl isoorientin was eluted with 30% MeOH, but maysin was eluted with 50% MeOH from the $C_18$ open column. Collected fractions were analyzed with HPLC by using revers-phase Ultras-phere $C_{18}$ column (4.6$\times$250mm, 5$\mu\textrm{m}$) and $H_2$O (10% MeOH containing 0.1% $H_3$${PO}_4$)/MeOH (100% MeOH containing 0.1% H$_3$PO$_4$) linear gradient from 20% to 90% MeOH for 35 minutes, a flow rate of 1 $m\ell$/min and detection at 340nm. The selected fractions were concentrated and applied to the silicic acid column. Maysin was eluted with 500$m\ell$ of 100% ethyl acetate from the silicic acid column for the first purification, and the purity of collected fractions was about 75%, but the purity from the second purification with the Cis column (1/2 $\times$ 43") was greater than 95%. FAB-MS spectral data was obtained with VG7O-VSEQ VG analytical fast atom bombardment mass (UK). $^1$H-NMR and $^{13}$ C-NMR data were obtained with Bruker DPX 400 MHz NMR spectrometers (German) in DMSO-d$_{6}$ at 400 and 100 MHz, respectively.vely.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.109-117
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• 1986

For the purpose of obtaining basic data which can be applied to processing of retort pouched shellfishes, retort pouched seasoned ark shell, Anadara broughtonii, was prepared. The frozen ark shell was thawed and seasoned with a mixed seasoning powder prepared with $10.0\%$ of sorbitol, $2.0\%$ of table salt and $0.5\%$ of monosodium glutamate at $5^{\circ}C$ for 10 hours, and then dried at $45^{\circ}C$ for 4 hours. The dried seasoned ark shell was coated with $1.0\%$ sodium alginate solution, dried with cola air blast for 2 hours and then vacuum-packed in the laminated plastic film bag (polyester/casted polypropylene= $12{\mu}m/70{\mu}m,\;15{\times}16cm$), and finally sterilized up to Fo=6.0 in hot water circulating retort at $121^{\circ}C$ for 10 minutes. The major fatty acids of raw ark shell and retort pouched seasoned ark shell products were 16:0, 20:5, 22:6, 18:0 and 18:3, and predominant free amino acids of those were lysine, arginine, glycine, alanine, glutamic acid and leucine. In nucleotides and its related compounds of raw ark shell and retort pouched seasoned ark shell products, the most abundant one was AMP, and total extract-N of those was chiefly consisted of free amino acids, betaine and nucleotide and its related compounds. During the processing procedure such as drying and sterilization, unsaturated fatty acids slightly decreased while saturated fatty acids increased, and total extract-N content decreased about a half. From the results of chemical and microbial experiments during storage, it was concluded that the products could be preserved in a good condition for 100 days at room temperature, and their duality could be improved by the coating treatment of sodium alginate solution.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.229-234
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• 2014

We analyzed drainage water from coir substrate in which cucumber plants were grown in winter and elucidated changes in pH, EC, and major nutrients according to the growth stages to recommend nutrient solution management appropriate to each growth stage. From the analysis of drainage solution the growth stages of cucumber were desirable to be divided into two, planting to fruit setting and fruit setting to harvest in case of nutrient solution management. The time required was about 3 weeks from planting to the first fruit setting and thereafter 7~10 days more until the first harvest. Approximately every 3~4 days were needed until the upper flowers bloomed. The time required from fruit setting to harvest was not different much among flowers as cucumber plants grew. From the experimental results, EC of supplied solution was recommended to maintain a little high to $3.0dS{\cdot}m^{-1}$ until before fruit setting and lower a little to $2.0{\sim}2.3dS{\cdot}m^{-1}$ after that. Of course, the amount of solution supply should be increased as plants grew. In case of each nutrients, the recommendation of concentrations of nitrogen, phosphorus and calcium were 700, 60, and $110mg{\cdot}L^{-1}$ each until before fruit setting, and then 660, 50, and $100mg{\cdot}L^{-1}$ each after fruit setting. The concentrations of potassium and magnesium are recommended to start from 400 and $80mg{\cdot}L^{-1}$ until fruit setting and lower a little after that.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.311-319
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• 1997

These studies were carried out to develop an artificial cultivation method. The diameter and thickness of pileus ranged $1.5{\sim}7.0\;cm$ and $0.8{\sim}3.0\;cm$, respectively. The diameters of stipe were $1.2{\sim}2.5\;cm$ and the lengthes were $4.5{\sim}9.0\;cm$. The spore fingerprint was white. The sizes were spore $10.8{\sim}12.2{\times}4.35{\sim}5.65\;{\mu}m$, basidia $50.0{\sim}59.2{\times}7.4{\sim}7.8\;{\mu}m$, nalsistidia $21.75{\sim}28.7{\times}4.8{\sim}6.1\;{\mu}m$, pileus hymenium cell $50.6{\sim}66.0{\times}4.4{\sim}6.7\;{\mu}m$, and stipe hymenium cell $28.6{\sim}33.0{\times}5.5{\sim}6.6\;{\mu}m$. The thirty percent mixture of rice and wheat bran into sawdust gives the high density of mycelia and the good development of fruiting structure. The optimum water contents of sawdust substrates were $60{\sim}65%$ in which condition the mycelium grows well and gives high density. In PP bottle cultivation, the first fruiting period was $6{\sim}8$ days earlier in nonscratching samples than scratching ones, but the quantity of fruiting body was higher in scratching samples than nonscratching ones. In the case of PP bag cultivation, the first fruiting was 10 days faster, and the quantity of fruiting bodies was 30% higher in samples with 30% wheat bran than those with rice bran. The fleshiness of stipe was $2{\sim}3$ times harder than that of pileus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.2
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• pp.181-188
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• 1989

The present study has been carried out to investigate the effect of Bactokil(made from didecyldimethyl ammonium chloride isopropanol and water) and Taipet-F (made from natural vitamin E, L-ascorbic acid, glyceride and gallic acid) on retarding lipid oxidation in boiled-dried anchovy. To process boiled-dried anchovy, boiled anchovy dried in cabinet drier $(dry-bulb\;temperature\;40^{\circ}C)$ for 1 hour were fronted with the Bactokil, the Taipet-F and mixture of Bactokil and Taipet-F, respectively. Anchovy fronted with chemicals were redried for 8 hours, packed in polyethylene film bag, and then stored at room temperature $(24{\pm}3^{\circ}C)$. These products were compared with control(untreated with chemicals) during storage. The changes in volatile basic nitrogen of each product was negligible during storage. The thiobarbituric acid and peroxide values of each product increased up to 10 days of storage, and then decreased. In color value of each product, L value increased, while n, b and ${\bigtriangleup}E$ values decreased during storage. The changes in brown pigment formation of each product increased up to final stage of storage. From the results of chemical analysis and sensory evaluation, the product treated with Taipet-F(0.5%, v/v) was the most effective on retarding lipid oxidation of the boiled -dried anchovy, followed by the product treated withthe mixture of Bactokil (0.04%, v/v) and Taipet-F (0.5%, v/v), the product treated with Bactokil(0.04%, v/v) and control, in the order named.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.6-13
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• 1986

Experiments were conducted to study the effects of formic acid on the quality of the rye silages at the different dry matter content (19.2, 28.6 and 32.2%) and different formic acid addition levels (0.00, 0.24, 0.48 and 0.71%). Rye were taken at vegetative stage (plant height 40cm) on November 29, 1984. Herbage were adjusted dry matter contents by wilting. Materials were ensiled in small polyethelene film bag after addition planned formic acid, and stored under room temperature. The results obtained are as follows: 1. In the visual observation of silage quality by addition of formic acid in unwilted silage show more clear brownish-yellow color and sweet flavor and less acidity compared with untreated formic acid. 2. The pH values of the silage increased by increasing DM content. At lower dry matter contents in materials the pH values decreased with increased formic acid levels. At higher dry matter content silage, however, non significant difference were observed. 3. The formation of total organic acid decreased by increasing DM content in the materials, and there appeared a significant difference (P<01) among formic acid levels. The organic acid contents in silage decreased with higher formic acid levels. 4. The water soluble carbohydrate in silage increased by increasing DM content. And it was also increased (P<01) with increased formic acid addition level. 5. The production of NH_3 - N decreased (P<01) with increasing the addition of formic acid, and decreased by increasing DM content in materials. 6. The in vitro dry matter digestibility of silages showed not difference among dry matter contents of the materials but at 0.71% addition of formic acid in unwilted silages appeared higher (P<05) digestibility compared the others (0.00% and 0.24%).

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.219-226
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• 2006

The wastes (the needle leaves and branches) produced from thinning the forest were fermented under an anaerobic condition (pine silage) to utilize as a forage source of ruminants. An in situ trial was conducted with two ruminally fistulated Korean native cows by 4 replicates (2 bags per cow), and in vivo digestibility of pine silage was estimated with five Korean native steers by 5 replicates in incomplete double turn-over design. In order to investigate feed efficiency and carcass traits, forty eight Korean native bulls were assigned to four treatments (0%, 25%, 50%, 75% of pine silage) with a completely randomized design in 12 pens accommodating 4 animals per pen. The amounts of concentrate and roughage allowed to experimental animals were in the range of 2.5% and 0.6% of body weight, respectively. Animals had freely accessed to mineral block and water in stanchion barn.An in situ crude protein digestibility of the roughage sources when suspended for 48 hrs in the rumen was higher for feeding the pine silage than the rice straw, whereas NDF digestibility was vice versa. No differences between the treatments were observed in in vivo digestibilities of dry matter, crude protein and NDF. Daily body weight gain was significantly (P<0.01) higher for the pine silage substitutions compared with the rice straw feeding except for the 25% silage feeding. The pine silage feeding did not affect feed efficiency.In carcass traits, marbling score tended to be higher for the 50% pine silage treatment than the other treatments while back fat thickness tended to be the thinnest for the rice straw feeding. From these results, it may be recommended to substitute pine silage, as a forage source, for rice straw by 50 percent.