• Title/Summary/Keyword: Polyethylene (PE)

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Effects of Seeding Date and Polyethylene Film Mulching on the Yield Potential and Agronomic Characteristics of Proso Millet (Panicum miliaceum L.) in Miryang, Korea (밀양지역에서 기장의 파종시기 및 PE 피복이 생육 및 수량에 미치는 영향)

  • Hyun, Jong-Nae;Hwang, Jae-Bok;Ko, Jee-Yeon;Jung, Ki-Youl;Kim, Kyeong-Hoon;Kim, Kyeong-Min
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.61 no.4
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    • pp.283-289
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    • 2016
  • This study was carried out to identify the optimum seeding dates for selecting a double-cropping system and to assess the effect of polyethylene film mulching on the yield of Proso millet. Seeds of the varieties Hwanggeumgijang and Ibaegchal were sown in Miryang on five different dates: 1st (May 25), 2nd (June 15), 3rd (June 25), 4th (July 5), and 5th (July 15), with and without polyvinyl mulching. The varieties have different characteristics, for example, Hwanggeumgijang is an early-maturing type and more sensitive to temperature, whereas Ibaegchal is a medium-maturing type and more sensitive to the duration for which it is exposed to sunlight. Late-sown Hwanggeumgijang had a short heading date from seeding and required a low accumulated temperature. It also had a shorter period of heading, a shorter culm length and a shorter diameter of stem. In contrast, it had had a higher number of ears $per\;m^2$ although similar ear length and similar 1000-grain weight. The yield potential of Hwanggeumgijang was found to decrease at a late seeding date. In particular, it significantly decreased at the seeding date of July 15. In the case of cultivation with polyvinyl mulching, the period of heading was shorter by 2-4 days and the yield potential was increased by approximately 12-32%. The length and diameter of culm in Ibaegchal were slowly decreased, but the length of ear, the 1000-grain weight and the yield potential were similar for all seeding dates (except July 15) and cultivation with and without mulching. When sown late, the length and diameter of the culm of Ibaegchal very rapidly decreased by the July 15 seeding date. The protein content of Ibaegchal was higher but the amlyose content of Ibaechal was lower compared to Hwanggeumgijang. At late seeding dates, the protein contents of the two varieties increased but the amylose contents were similar.

Investigation of Heavy Metal Migration from Food Contact Materials used for Food Delivery Using an Inductively Coupled Plasma-Mass Spectrometer

  • Chae-Yeon Hwang;Young-Jun Kim
    • Journal of Food Hygiene and Safety
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    • v.38 no.2
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    • pp.37-45
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    • 2023
  • The surge in food delivery systems during the coronavirus 2019 pandemic necessitated this study of heavy metal migration from food contact materials (FCMs). A total of 104 samples of FCMs, comprising 51 polypropylene (PP), 21 polyethylene (PE), and 32 polystyrene (PS) samples of six different types of FCMs (containers, covers, table utensils, cups, pouches, and wrappers) used for food delivery distributed in Korea, were collected and investigated for migration of three heavy metals (Pb, Cd, and As) using inductively coupled plasma-mass spectrometry (ICP-MS) to determine whether they complied with Korea's Standards and Specifications for Utensils, Containers, and Packages. Acetic acid (4%, v/v) was used as the food simulant, and tests were performed at 100℃ (in harsh conditions) for 30 min. Linearity of Pb, Cd, and As showed acceptable results with a coefficient of determination (R2) value of 0.9999. Limit of detection (LOD) and limit of quantification (LOQ) of Pb, Cd, and As were 0.001, 0.001, and 0.001 ㎍/L and 0.002, 0.003, and 0.003 ㎍/L, respectively. Accuracy and precision results complied with the criteria presented in the European Commission Joint Research Centre guidelines. The average concentration of Pb, Cd, and As migration detected in a total of 104 samples was 0.009-0.260 ㎍/L, which was very low compared with the migration specification set in the Standards and Specifications for Utensils, Containers, and Packages. The maximum level of Pb corresponded to 0.23% of the migration limit. There were no samples exceeding the limit. Thus, this study confirmed that the heavy metal contents of FCMs used for delivery food distributed in Korea were safely managed. The data from this study represent an invaluable source for science-based safety management of hazardous heavy metals migrating from FCMs used in the food delivery industry.

Effect of temperature and relative humidity in refrigerator on quality traits and storage characteristics of Pre-packed Hanwoo loin (냉장고 내 온도와 상대습도가 포장 한우 등심의 품질 및 저장 특성에 미치는 영향)

  • Seol, Kuk-Hwan;Kim, Ki Hyun;Kim, Young Hwa;Youm, Kyung Eun;Lee, Mooha
    • Korean Journal of Agricultural Science
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    • v.41 no.4
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    • pp.415-424
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    • 2014
  • This study was carried out to determine the effect of storage condition, such as temperature or relative humidity (RH) in home-style refrigerator, on the change of quality traits and storage characteristics of Hanwoo M. longissimus to find out the condition for prolongation of shelf-life with maintaining the meat quality for consumers. Samples were sliced in $1{\pm}0.2cm$ thickness, and packed in foamed polystyrene tray with linear low-density polyethylene (LLD-PE) film to simulate the pre-packed Hanwoo loin sold in retail market, then stored in home-style refrigerator ($5^{\circ}C$/17% RH, Control), and chambers of $5^{\circ}C$/55% RH (T1), $5^{\circ}C$/85% RH (T2), and $-1^{\circ}C$/99% RH (T3), respectively. Quality traits (color, pH, water holding capacity, shear force and grilling loss) and storage characteristics (thiobarbituric acid reactive substances, volatile basic nitrogen and total microbes) were measured at 1, 4, 7, 14 and 21 days after storage. Lightness of Hanwoo loin stored in T1, T2 and T3 were higher than that of control until 14 days of storage, however at the end of storage (21 days) control showed significantly higher than other treatments (p<0.05). Redness and Yellowness of Hanwoo loin samples stored in T1 and T3 were significantly higher than others during all storage period (p<0.05). The water holding capacity (WHC) of control was significantly higher than others until 14 days of storage (p<0.05), however, Hanwoo loin stored in T2 was the highest ($63.64{\pm}7.62kg/cm^2$) at 21 days of storage. Hanwoo loin stored in T1 showed significantly lower shear force than others during all storage period (p<0.05). There was no consistent tendency in pH and grilling loss during storage in all treatments. Hanwoo loin stored in T1 showed lower TBARS value than others during storage period, however there was a rapid increase to $0.34{\pm}0.27mg$ malonaldehyde/kg meat at 21 days of storage. And, all the treated samples (from T1 to T3) showed significantly lower VBN values at 21 days of storage (p<0.05). The population of total aerobic microbes were significantly increased in all treatments as storage period increasing, and the population of T3 ($2.28{\pm}0.57logCFU/g$) was the lowest at 21 days of storage (p<0.05). From those results, it could be predicted the better storage condition to maintain the meat quality and prolong the shelf-life of Hanwoo loin by lowering the temperature and adjusting the humidity about 55%.

Effect of storage condition on sensory properties and fatty acid composition of pre-packed Hanwoo loin (저장조건이 포장 한우 등심의 관능적 특성 및 지방산 조성에 미치는 영향)

  • Seol, Kuk-Hwan;Kim, Ki Hyun;Kim, Young Hwa;Youm, Kyung Eun;Lee, Mooha
    • Korean Journal of Agricultural Science
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    • v.42 no.1
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    • pp.37-46
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    • 2015
  • This study was carried out to determine the effect of storage condition, such as temperature and relative humidity (RH), on the change of sensory properties and free fatty acid composition of pre-packed Hanwoo loin (Musculus longissimus) until $21^{st}$ day of storage. The Hanwoo loin was sliced in $1.0{\pm}0.2cm$ thickness and each of the sliced pieces was packed in a foamed polystyrene tray with linear low-density polyethylene (LLD-PE) film to simulate the pre-packed Hanwoo loin sold in retail market, then stored in home-style refrigerator (Con; $5^{\circ}C$, 17%RH), and temperature and RH controled chambers (T1; $5^{\circ}C$, 55%RH, T2; $5^{\circ}C$, 85%RH, and T3; $-1^{\circ}C$, 99%RH), respectively. The sensory characteristics of pre-packed Hanwoo loin during storage in different conditions were measured on raw or after cooking. After 21 days of storage, the loin stored in T3 showed significantly high color and acceptability scores ($7.46{\pm}1.07$, $7.06{\pm}1.36$, respectively) on raw loin, and flavor and acceptability scores ($7.16{\pm}0.90$, $6.90{\pm}0.92$, respectively) on cooked loin than those of others (p<0.05). The concentration of 12 fatty acids of pre-packed Hanwoo loin during storage in different conditions were analysed. The concentration of oleic acid (C18:1, $39.92{\pm}3.22%$), palmitic acid (C16:0, $28.20{\pm}2.42%$), and stearic acid (C18:0, $12.59{\pm}2.79%$) was high in Hanwoo loin on $1^{st}$ day of storage. The concentration of palmitic acid of Hanwoo loin stored in T2 was increased significantly after $4^{th}$ day of storage (p<0.05), and the concentration of myristic acid(C14:0) of Hanwoo loin stored in treated chamber (T1 to T3) was significantly higher than Con after $14^{th}$ day of storage (p<0.05). The concentration of linolenic acid (C18:3) of Hanwoo loin was decreased significantly after $4^{th}$ day of storage in all tested storage conditions (p<0.05). However, there was no significant or consistent change in the concentration of oleic acid (C18:1) during storage period in every Hanwoo loin stored in tested conditions. Although, the concentration of total monounsaturated fatty acids (MUFA) was decreased in Con and T2 (p<0.05), there was no consistent change in the monounsaturated fatty acids to saturated fatty acids ratio (MUFA/SFA) during storage period (p>0.05). From those results, it was considered that storage condition affects on the sensory acceptability and fatty acid composition of pre-packed Hanwoo loin as storage period was increased.

Salt Accumulation in Horticultural Soils of PE Film House in Chungbuk Area (충북지역(忠北地域) 시설원예재배지(施設園藝栽培地) 토양(土壤)의 염류집적(鹽類集積) 실태조사(實態調査))

  • Yuk, Chang-Soo;Kim, Jai-Joung;Hong, Soon-Dal;Kang, Bo-Goo
    • Korean Journal of Soil Science and Fertilizer
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    • v.26 no.3
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    • pp.172-180
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    • 1993
  • Chemical properties of the soils were surveyed in the field of vinyl houses concentrated in the area of Bunpyong-dong and Shinchon-dong of Cheongju, Chilgeum-dong of Chungju and Gageum-myeon of Jungweon-gun. Chungcheongbuk-do province. 1. Content of chemical component of the soil in the vinyl house was higher than in open field. In more than half of the vinyl house soils surveyed, electric conductivity was more than 4.0 mmhos/cm and available phosphate was more than 1,000ppm. 2. Contents of availble phosphate and exchangeable potassium were increased with years of cultivation and their content of accumulation in soil were in the order of Bunpyong-dong>Shinchon-dong>Gageum-myeon>Chilgeum-dong. While their mobility was comparatively low. 3. $NO_3$-N content was remarkably higher in vinyl house soil and the older in cultivation made $NO_3$-N content higher same as the case of available phosphate content. However easy leaching of $NO_3$-N through soil profile is expected due to the fact that $NO_3$-N content was rapidly decreased by removal of polyethylene film cover from the frame of house after harvest of crops. 4. It is a tendency that various chemical contents of vinyl house soils wer higher in 1992 than in 1988~1990, especially much higher from the area of Bunpyong-dong and Shinchon-dong of Cheongju. 5. Salt accumulation in vinyl house soil has been increased with continuing cultivation. Therefore amount of fertilizer application should be controlled in order to avoid salt toxicity, quality deterioration for crop and salt contamination of ground water.

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Performance Evaluation of Bio-Membrane Hybrid Process for Treatment of Food Waste Leachate (음식물 침출수 청정화를 위한 파일롯 규모의 생물-분리막 복합공정의 성능 평가 연구)

  • Lee, Myung-Gu;Park, Chul-Hwan;Lee, Do-Hoon;Kim, Tak-Hyun;Lee, Byung-Hwan;Lee, Jin-Won;Kim, Sang-Yong
    • KSBB Journal
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    • v.23 no.1
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    • pp.90-95
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    • 2008
  • In this study, a combined process of sequential anaerobic-aerobic digestion (SAAD), fluidized-bed bioreactor (FBBR), and ultrafiltration (UF) for the treatment of small scale food waste leachate was developed and evaluated. The SAAD process was tested for performance and stability by subjecting leachate from food waste to a two-phase anaerobic digestion. The main process used FBBR composed of aerators for oxygen supply and fluidization, three 5 ton reaction chambers containing an aerobic mesophilic microorganism immobilized in PE (polyethylene), and a sedimentation chamber. The HRTs (hydraulic retention time) of the combined SAAD-FBBR-UF process were 30, 7, and 1 day, and the operation temperature was set to the optimal one for microbial growth. The pilot process maintained its performance even when the CODcr of input leachate fluctuated largely. During the operation, average CODcr, TKN, TP, and salt of the effluent were 1,207mg/L, 100mg/L, 50 mg/L, and 0.01 %, which corresponded to the removal efficiencies of 99.4%, 98.6%, 89.6%, and 98.5%, respectively. These results show that the developed process is able to manage high concentration leachate from food waste and remove CODcr, TKN, TP, and salt effectively.

The Effects of Treatment with Cyclophosphamide and Methylprednisolone on Expression of Endothelin-1 in Unilateral Instillation of Paraquat-induced Pulmonary Fibrosis in Guinea Pigs (Paraquat의 편측 기관지 주입에 의해 유발된 폐섬유화증에서 Cyclophosphamide와 Methylprednisolone의 투여에 따른 Endothelin-1의 발현의 변화)

  • Lee, So-Ra;Jeong, Hye-Cheol;Kim, Kyung-Kyu;Lee, Sang-Youb;Lee, Sin-Hyung;Cho, Jae-Youn;Shim, Jae-Jeong;In, Kwang-Ho;Choi, Jong-Sang;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.6
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    • pp.775-785
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    • 1999
  • Background : The herbicide paraquat can cause severe lung injury and fibrosis in experimental animals. In this study we have investigated the changes in lung endothelin-1(Et-1) levels and immunohistochemical localization in relation to treatment with cyclophosphamide and methylprednisolone in paraquat induced pulmonary fibrosis in guinea pigs. Material and methods : 29 male Hartley guinea pigs were divided into 4 groups. Group I was normal control. Paraquat was instilled into the lung of guinea pig of group II, III and IV unilaterally. Group II was treated with cyclophosphamide and methylprednisolone. Group III was treated with methlprednisolone. Group IV was not treated. The degree of fibrosis was evaluated by H-E stains and Masson's trichrome stains and cell activity was assessed by Et-1 immunohistochemical stains. Statistical evaluation was performed using the Kruskawallis oneway analysis. Results : Paraquat induced an increase in numbers of fibroblasts and total amount of lung collagen in Group IV compared to the normal controls. There was no significant difference in total numbers of fibroblasts between any of paraquat instilled groups, but there was significant increase in total amount of collagen in Group IV compared to group II and III (p<0.05). The treatment of cyclophosphamide and methyprednisolone suppressed the growths of both fibroblasts and collagen, but this suppression was stastically significant only in the case of collagen Et-1 immunoreactivities of bronchial epithelium, type II pneumocytes, endothelial cells and fibroblast in group II and III were decreased compared to those in group IV. Conclusion : These results demonstrate that Et-1 is an important contributing factor in the pathogenesis of pulmonary fibrosis. Et-1 is synthesized and released by bronchial epithelium, Type II pneumocyte, endothelial cells, alveolar macrophages and fibroblasts. Especially they are associated with alveolar macrophage and fibroblasts. We conclude that combined therapy of cyclophosphamide and methylprednisolone are more effective in the control of Et-1 expression and collagen deposition.

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Growth Characteristics of Juvenile Abalone, Haliotis discus hannai by Reared Methods in order to High Density Intermediate Culture in Land-based Tank (육성수조 내 북방전복, Haliotis discus hannai 치패 고밀도 중간양성 사육방식별 성장특성)

  • Lee, Si-Woo;Kim, Byeong-Hak;Park, Min-Woo;Kim, Tae-Ik;Son, Maeng-Hyun
    • The Korean Journal of Malacology
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    • v.31 no.2
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    • pp.83-92
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    • 2015
  • The effect of different intermediated rearing method by expanding the attached floor space in order to highly density culture on the growth characteristics and survival rate of the juvenile abalone, Haliotis discus hannai, were investigated in land-based tanks. The intermediated culture methods was determined thru the shelter counts and layer for 10 month with two replicates : the single layer shelter (SLS), the double layer shelter (DLS), the triple layer shelter (TLS) and the single layer shelter under net cage (SLSNC). In addition, the culture on shallow race way tank had to set up as culture of the ditch raceway tank (CDRT) and the floor race way tank (CFRT). In the growth performance of reared abalone (initial mean shell length $54.18{\pm}7.39mm$ and weight $1.93{\pm}0.14g$) at experimental tanks, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth was not significant at each experimental tanks except SLSNC. As well as too, weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to weight was not significant at each experimental tanks except SLSNC, too. Survival rates of CDRT and CFRT was lower than those of different experimental tanks (P < 0.05). Therefore, these results is showed that high density different intermediated rearing method by expanding the attached floor space for juvenile H. discus hannai was not have difference as growth performance and survival rate both one layer shelter and multi layer shelter. Also, it is considered that shallow race way tank was not useful rearing for the juvenile intermediate culture of H. discus hannai in land based.

Effects of combination treatment with sulfur dioxide generating pad and modified atmosphere packaging (MAP) on the quality of 'Campbell Early'grape under simulated export conditions (모의수출조건에서 유황패드와 MAP 복합처리가 '캠벨얼리' 포도의 품질에 미치는 영향)

  • Choi, Mi-Hee;Lee, Jin-Su;Lim, Byung-Seon
    • Food Science and Preservation
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    • v.24 no.6
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    • pp.734-745
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    • 2017
  • The effects of combination treatment with sulfur dioxide generating pad ($SO_2$ pad) and modified atmosphere packaging (MAP) on grape quality were examined under simulated exporting condition and actual export to Los Angeles, USA. The 'Campbell Early' grape harvested in Hwaseong, Gyeonggi was precooled at $0^{\circ}C$, selected and packaged at $10^{\circ}C$, and stored at $0^{\circ}C$ for 30 days. The treatment was as follows: general export packaging (control), only $SO_2$ pad, combination of $SO_2$ pad and MAP (perforated polyethylene film, $SO_2$ pad+MA). In case of control and only $SO_2$ pad under simulated exporting condition, the grape quality changes with storage time were decrease in hardness and brush length, increase in stem browning, and increased in shattering rate. The treatment of $SO_2$ pad+MA was the most effective in preserving the grape quality since $SO_2$ concentration inside the package remained around 2.9 ppm by MA film. Grape exports from harvest to local distribution of the USA took 30 days, and only $SO_2$ pad+MA package showed no fungus, maintained brush length and rachis color, and was lowest at 4.0% of shattering rate since the concentration of $SO_2$ in the package was about 4.0 ppm. As a result, it was considered that the combination of $SO_2$ pad and MA was the most effective way to maintain freshness of grape during long-term marine transportation and extend the shelf-life in exporting countries.

Quality Evaluation of Minimally Processed Asian Pears (신선편의 식품화된 신고배의 저장 중 이화학적 품질변화)

  • Kim, Gun-Hee;Cho, Sun-Duk;Kim, Dong-Man
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1523-1528
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    • 1999
  • The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

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