• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.167-174
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• 2013

Six kinds of sprout vegetables were applied three and six types of non-perforated breathable propylene films (NPB film) for individual and mixed modified atmosphere (MA) package condition at $10^{\circ}C$ on this study. As a tah tasai, kohlrabi, rape, chinese cabbage, red radish, broccoli sprouts were packaged by 20,000, 60,000, and 100,000 $cc{\cdot}m^{-2}{\cdot}day{\cdot}atm$ non-perforated breathable films for seven days storage. Mixed sprout vegetables were used 20,000 cc, 40,000 cc, 60,000 cc, 80,000 cc, and 100,000 $cc{\cdot}m^{-2}{\cdot}day{\cdot}atm$ non-perforated breathable films for seven days storage. Loss rate of fresh weight, changes of carbon dioxide, oxygen, and ethylene gas concentration were measured during the storage. Visual quality and off-flavor were rated by panel tests after seven days storage. Each sprout vegetable storage with film tests had been shown under the 0.5% fresh weight loss in every packaged films, and the 20,000cc NPB film package had been suitable atmosphere condition in the carbon dioxide and oxygen gas concentration. Appearance and off-odor of sprouts packaged with 20,000cc NPB film were shown better than other films because of the proper gas movement through the film to outside during the storage. Fresh weight loss of the mixed sprout vegetables had no difference among the NPB films for seven days storage. The 20,000 cc film had been resulted in that exchange rate of carbon dioxide and oxygen was highest cause of low film permeability than sprouts respiration. But the film is not good for storage because it has been made poor value of off-order even showed high visual quality from panel test after storage. 40,000 cc and 60,000 cc non-perforated breathable films were more suitable for mixed sprout vegetable storage at $10^{\circ}C$. These result suggested that 20,000 cc NPB film was good for single packaged sprout vegetable and 40,000 cc and 60,000 cc non-perforated breathable films were good for mixed packaged sprout vegetable.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.180-184
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• 2018

This study was conducted to examine the effect OTR film type on the quality of garden cress (Lepidium sativum L.) baby leaf during MA storage. Garden cress harvested at baby leaf size of 10cm plant height packed with 1,300 cc, 10,000 cc, 20,000 cc, 40,000 cc, and $80,000cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ OTR (oxygen transmission rate) films and MP (micro-perforated) film, and then stored at $8^{\circ}C$ for 10 days. All of the OTR film treatments showed a decrease of 0.5% fresh weight until the storage end date and a 1.3% decrease in the MP film treatment. The oxygen concentration in the packaging during storage was maintained at 18% or more in 20,000 cc, 40,000 cc, and 80,000 cc OTR film treatments, while the 1,300 cc OTR film treatment decreased to 11% at the storage end date. And the concentration of carbon dioxide was steadily increased in the 1,300 cc and 10,000 cc OTR film treatments to show the levels of 4.5% and 3.4%, respectively, and the other OTR film treatments showed a concentration of less than 1%. Ethylene concentration in the package was maintained at the highest level of $3-5{\mu}L{\cdot}L^{-1}$ in the 1,300 cc treatment during the storage period. The lowest odor and the highest quality of appearance were observed in the 1,300 cc treatment, but the MP film treatment and the other OTR treatments lost marketable quality due to yellowing. The color of garden cress baby leaf was changed the lowest in 1,300 cc treatment that showed the highest chlorophyll content and Hue angle value, lowest $b^*$ value, present of yellowing at end of storage date. Therefore, 1,300 cc treatment which was most effective for yellowing and odor suppression during storage is considered to be suitable for packaging of garden cress baby leaf.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.24 no.2
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• pp.85-89
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• 2018

The effects of distribution temperature due to season all changes on quality and storability of baby leaf beet (Beta vulgaris L.) was examined in modified atmosphere (MA) packages. The beet leaf had been harvested at the 10 cm leaf length stage and packaged with an oxygen transmission rate (OTR) film of $1,300cc{\cdot}m^{-2}{\cdot}day^{-1}{\cdot}atm^{-1}$ and then held at 4 different distribution temperatures which were $-2^{\circ}C$, $4^{\circ}C$, $20^{\circ}C$, or $30^{\circ}C$ for 5 hrs and then stored for 18 days at $8^{\circ}C$. The loss of fresh weight of packged baby leaf beet was lowest at the $4^{\circ}C$ treatment, and below 0.6% in all distribution temperature treatments. The atmosphere composition in packages did not show any significant differences among treatments. The oxygen conc. was the highest at 18.0% after the $4^{\circ}C$ treatment, carbon dioxide conc. showed the maximum value of 4% at the $30^{\circ}C$ and $-2^{\circ}C$ treatments, and ethylene conc. was highest at the $10^{\circ}C$ treatment after 10 days in storage. The hardness was the highest at the $4^{\circ}C$ treatment on the final storage day. The $4^{\circ}C$ treatment showed the highest visual quality and the lowest off-odor and aerobic plate count. Therefore, it is necessary to establish a low-temperature distribution system which is controlled under $4^{\circ}C$, because the baby leaf beet's storability and microbial growth are effected even during a short time of 5 hrs during the distribution process.

• Polymer(Korea)
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• v.30 no.4
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• pp.298-304
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• 2006

Blends of poly (acrylic acid-co-maleic acid)(PAM) with poly (vinyl alcohol)(PVA) were obtained by solution blending. The blends were solvent-on to a film to examine thermo-mechanical properties and gas permeability. The transition temperatures $(T_g\;and\;T_m)$ of the blends remained constant regardless of PAM contents. However, the values of enthalpy changes corresponding to melting transition $({\Delta}H_m)$ and initial degradation temperature $({T_D}^i)$ were decreased with increasing PAM content. The values of ultimate strength and initial modulus gave the maximum value at the 12 wt% PAM then decreased with further increase of PAM content up to 15 wt%. To measure the gas permeability of the PVA/PAM blend films, the PVA blend solutions were coated onto both biaxially oriented propylene (BOPP) and poly (ethylene terephthalate)(PET) films. The oxygen transmission rate $(O_2\;TR)$ permeability values mono- tonically decreased with increasing PAM content. However, moisture vapor transmission rate was not affected by PAM content.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.25-31
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• 2018

This study investigated the effect of different $O_2$ transmission rate (OTR) of films on surface temperature, weight loss, pH, $O_2$, $CO_2$ and sensory characteristics, microbial quality, total phenolic contents and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity of fresh-cut lettuce during storage at $10^{\circ}C$ for 7 days. $80{\pm}5g$ of fresh-cut lettuce were packaged with oriented polypropylene films respectively. The OTR of packaging materials was 5,000, 8,000 and $10,000cc/m^2{\cdot}day{\cdot}atm$. Quality characteristics showed significant differences during storage. The surface temperature was averaged 13 and lower in higher OTR of films. The weight loss of lettuce ranged from 2.8 to 5.4% and the highest loss showed in $5,000cc/m^2{\cdot}day{\cdot}atm$ of film. pH was increased during storage and the highest pH was found in $5,000cc/m^2{\cdot}day{\cdot}atm$. The $O_2$ content in the packaging was decreased with increasing $CO_2$ content during storage. The lowest $CO_2$ was found in $10,000cc/m^2{\cdot}day{\cdot}atm$. As OTR was decreased, antioxidant profile of lettuce was decreased. Total aerobic bacteria showed from 5.48 to 6.59 log CFU/g. From the result of the overall sensory test, the marketability of fresh-cut lettuce stored at $10^{\circ}C$ seemed to be maintained effectively over 5 days.

• Clean Technology
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• v.18 no.1
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• pp.57-62
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• 2012

Aqueous poly (vinyl alcohol) (PVA) solution was modified by using hydrophobic vinyltriethoxysilane (VTEOS) and then adding different amounts of poly (acrylic acid) (PAA) to the resulting solution. Thermal and mechanical properties, contact angle, water vapor transmission rate (MVTR) and oxygen gas transmission rate ($O_2TR$) of the film samples fabricated by these solutions were investigated. The glass transition temperature (Tg) of the VTEOS-modified films was sightly increased and the value remained unchanged according to the amount of PAA. The tensile strength of the VTEOS-modified films was found to be 9.48~10.72 $kg/mm^2$ which showed no significant difference compared with that of PVA. The film prepared with VTEOS-modified PVA/PAA (= 90/10), of which the swelling and solubility were measured to be 198% and 0%, respectively, showed improved water-resistance. The MVTR and $O_2TR$ for the PET film (thickness 50 ${\mu}m$) coated with VTEOS-modified PVA/PAA (= 90/10) film (thickness 2.5 ${\mu}m$) were measured to be 11.04 $g/m^2/day$ and 3.1 $cc/m^2/day$, respectively.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.77-84
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• 2021

This study attempted to find a way to maintain the quality of mixing baby wild leaf vegetables with existing baby leaf vegetables in various ratios. The crops for mixing baby leaf vegetables were Peucedanum japoincum Thunberg and Ligularia stenocephala, as wild vegetables, and red romaine, which is widely used in young leafy vegetables. The mixing ratio of red romaine and wild vegetables was red romaine 0: mantilla oil 5: L. stenocephala ratio 5 (R0: P5: L5), red romaine 3.3: P. japoincum 3.3: L. stenocephala ratio 3.3 (R3.3: P3.3: L3.3), red romaine 5: P. japoincum 2.5: L. stenocephala 2.5 (R5: P2.5: L2.5), red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1), red romaine 10: P. japoincum 0: L. stenocephala 0 (R10: P0: L0). All treatments were packaged in OTR (oxygen transmittance) 10,000 cc m-2·day-1·atm-1 film and stored for 27 days at 2℃/85% RH conditions. Fresh weight, carbon dioxide, oxygen, and ethylene concentrations of the baby leaf packages were examined approximately every 3 days, and visual quality, chlorophyll content, and chromaticity were examined on the 27th day of storage. The oxygen and carbon dioxide concentration in the packages were affected by the respiration rate of the crop. As the mixing ratio of lettuce, which had a low respiration rate, increased, the oxygen concentration in the packages was higher and the carbon dioxide concentration was lower. Oxygen concentration decreased significantly after 15 days, but was remained above 16%, and on the contrary, carbon dioxide concentration was kept at 1-4% until the 15th, and then gradually increased to 2-5% on the 27th day. The concentration of ethylene was maintained at 3-6 µL·L-1 until the end of storage (27th day). Visual quality score measured at the end of storage was slightly less than 3.0, which is the limit of marketability of all treatments. Although there was no significant difference, the chlorophyll content (SPAD) of red romaine and P. japoincum were most similar with an initial value in R8:P1:1 treatment, and L. stenocephala was higher value in R8:P1:L1 and R5:P2.5:L2.5 treatments at the end of storage. The leaf color (L∗, a∗, b∗, chroma) of the three crops at end of storage compared with the heat map showed the least change in the R5:P2.5:L2.5 and R8:P1:L1 treatments at the end of storage. Among them, R8:P1:L1 treatment maintained the highest chlorophyll content, the second lowest ethylene concentration, and adequate carbon dioxide concentration of 2-3%. Therefore, it is judged that the mixed ratio of red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1) is most suitable for the mixed package of baby leaf vegetables of these three crops.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.447-455
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• 2011

To investigate the effects of the improvement of postharvest quality on fresh tomato, antimicrobial microperforated (AMP) films were prepared and their antimicrobial abilities were observed. AMP films were made by coating different types of natural antimicrobial agents such as cinnamon, clove, and clary sage essential oils into microperforated (MP) films. Cinnamon essential oil of 10% (v/v) has proven to be very effective as inhibitor of the mold growth on tomato, compared to the clove and clary sage essential oils. Quality changes of fresh tomatoes packed using the natural AMP films (AMP10 and AMP30) and MP films (MP10 and MP30) during storage were evaluated. Total microbial growth, weight loss, firmness, lycopene content, and decay rate as the major quality parameters were monitored over 9 days at $15^{\circ}C$. The oxygen transmission rates and mechanical properties between the natural AMP and MP films were also compared. There was no significant difference in change of oxygen transmission rate, tensile strength and elongation between the AMP and MP films. For storage studies, the freshness of tomato packaged in AMP30 film was higher than that in OPP film (the control), MP10, MP30, and AMP10 films. Especially, AMP30 film exhibited high efficiency compared to the control for tomato decay during storage periods. Based on the results, the microperforation and antimicrobial properties of the packaged films may significantly affect the maintenance of an optimum gas composition within the package atmosphere for increasing the storage life and quality of produce. They were also effective on the inhibition of microbial growth by controlled release of antimicrobial agent at an appropriate rate from the package into the tomato. Natural antimicrobial agent coating microperforated films could use potential functional package as a method of extending the freshness of postharvest tomato for storage.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.402-406
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• 2019

Recently, semiconducting organic materials have been spotlighted as next-generation electronic materials based on their tunable electrical and optical properties, low-cost process, and flexibility. However, typical organic semiconductor materials are vulnerable to moisture and oxygen. Therefore, an encapsulation layer is essential for application of electronic devices. In this study, SiN_x thin films deposited at process temperatures below 150 ℃ by plasma-enhanced chemical vapor deposition (PECVD) were characterized for application as an encapsulation layer on organic devices. A single structured SiN_x thin film was optimized as an organic light-emitting diode (OLED) encapsulation layer at process temperature of 80 ℃. The optimized SiN_x film exhibited excellent water vapor transmission rate (WVTR) of less than 5 × 10^-5 g/㎡·day and transmittance of over 87.3% on the visible region with thickness of 1 ㎛. Application of the SiN_x thin film on the top-emitting OLED showed that the PECVD process did not degrade the electrical properties of the device, and the OLED with SiN_x exhibited improved operating lifetime

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.99-105
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• 1999

The preparation and the functional properties of methylcellulose (MC) and hydroxypropyl-methylcellulose (HPMC) edible films with and without calcium were investigated. All the prepared films exhibited transparent and whitish color with $2.38{\sim}3.55$ haze intensity. Tensile strength of MC films were stronger than HPMC films with and without calcium, and moreover addition of calcium increased tensile, but elongation of HPMC film was specially lower than the other films. Solubility of films did not differ with calcium addition but decreased with increasing viscosity in HPMC films. water vapor transmission rate (WVTR) of HPMC and MC film were not affected by calcium, but viscosity of film's raw material was important to determine WVTR in HPMC. Oxygen permeabilities of MC films were lower than those of HPMC films, and became lower with calcium addition. According to scanning electron microscope (SEM) observation on the surface characteristics, MC film with calcium had relatively uniform and smooth surface than HPMC films.