• Food Engineering Progress
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• v.23 no.1
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• pp.55-61
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• 2019

For the vessel export of strawberries, modified atmosphere package (MAP) using polyamide (PA) film and linear low density polyethylene (LLDPE) film was investigated to extend the shelf life of strawberries. Because the temperature and relative humidity changes of the MAP were lower than the changes of the control, the weight loss of the MAP were lower than that of the control. The low oxygen level and high carbon dioxide level were effective to decrease the fungal decay rate and to increase the hardness of strawberries. The Hunter's color differences before and after storage showed no distinct difference between the MAP and the control. The lightness had a tendency to decrease while the redness increased. There were no significant changes of the soluble solids during the storage. The shelf life of strawberries could be extended to 16 days using the MAP considering the weight loss and the fungal decay rate. Thus, this MAP method using PA film and LLDPE film was effective to extend the shelf life of strawberries.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.121-125
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• 2006

To study the effects of plasticizer concentration and its ratio on the physical properties of silk fibroin films, polyethylene glycol (PEG) was used at 4 different concentrations; 1, 2, 3, $4.5\%$ (w/v). Tensile strength (TS) and water vapor permeability (WVP) increased with the increase of PEG concentration, while opposite trend was observed for percent elongation of silk fibroin films. WVP of silk fibroin films increased from $2.54\;ng{\cdot}m/m^2spa$ for $1\%$ of PEG to $5.41\;ng{\cdot}m/m^2sPa$ for $4.5\%$. In addition, a mixture of PEG and glycerol (Gly) as a plasticizer was used at the ratio of 100:0, 75:25, 50:50, 25:75, and 0:100 (w/w). Percent elongation of the films was improved to $130.95\%$ when the ratio of 75:25 was used. On the contrary, WVP of silk fibroin films increased with the decrease of the ratio of PEG:Gly. Effect of the plasticizer concentration and its ratio on the color of silk fibroin films was negligible. These results suggest that mixture of PEG and Gly as a plasticizer provide more flexible than PEG alone in silk fibroin films, and the best ratio of PEG to Gly was 75:25.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.101-106
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• 2005

Photocurable modified 6 functional polyacrylate(PA-1) were prepared from dipentaerythritol derivatives (DPET) and acrylic acid, and 12 functional polymethacrylate(PA-2) were prepared from dipentaerythritol derivatives (DPET), trimellitic anhydride, and glycidyl methacrylate. And physical properties of photocurable modified poly(meth)acrylate were increased with increasing functionality of (meth)acrylate. Thermal stability of UV cured film obtained by using TGA was shifted to higher temperature as the increasing of functionality. Hardness, abrasion resistance and tensile strength of UV cured film were increased with increasing functionality of (meth)acrylate. Values of yellow index were increased with increasing functionality of (meth)acrylate.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.178-185
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• 2021

In this study, polyvinyl alcohol (PVA) and polypropylene glycol (PPG)-based polyurethane dispersion resin for wound coating was synthesized. And the physical properties of the sample were coated on the surface of the film sample and the leather (Full-Grain) to study the physical properties change. In the case of tensile strength, PUD-PA1, which reacted with the least amount of PVA, showed the highest resistance at 2.00 kgf/㎟. Likewise, the rate of elongation was measured as high as 554% for PUD-PA1, which reacted with the least amount of PVA. The abrasion resistance measurement result showed that as the PVA response increased, the strength of the surface decreased to 36.77 mg.loss.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.224-232
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• 2015

The effects of cold plasma (CP) treatments on the physicochemical and biodegradable properties of a corn biomass-containing polyester (CBPE) film were studied. The CBPE film was treated with CP generated by $N_2$, $O_2$, He, Ar, or dry air at 400-900 W and 667 Pa for 10-40 min. The glass transition temperature of the CBPE film ($-30.2--28.6^{\circ}C$) was not affected by the CP treatment, while the elastic modulus and water vapor permeability decreased (p<0.05). The ink printability was improved by the treatment and the improved printability was maintained during storage for 56 days at room temperature. Roughness of the film increased after treatments and the level of roughness appeared to increase during storage. Heat and microbial biodegradability of the CBPE film was improved by the air-CP treatment (p<0.05). These results have demonstrated the potential of applying CP treatments to improve the flexibility, printability, and biodegradability of CBPE films.

• Korean Journal of Food Science and Technology
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• v.44 no.6
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• pp.711-715
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• 2012

A laminate-composite film was developed using industry co-products of defatted mustard meal (DMM) and whey protein isolate (WPI). An individually prepared DMM-based film (DMM film) and a WPI-based film (WPI film) were thermally laminated at $130^{\circ}C$ at a rate of 30 cm/min. Microscopic images exhibited that the DMM film and the WPI film were continuously attached in the laminate without void spaces. The tensile strength, elongation at break, and water vapor permeability for the laminate were 0.7MPa, 4.0%, and $6.9g{\cdot}mm/kPa/h/m^2$, respectively. Stretchability and heat seal strength of the laminate were higher than those of the un-laminated DMM film. The film layers of the laminate were physically overlapped, not forming new biopolymer units induced by molecular interactions. The opportunity for DMM films to be used as food packaging materials for wrapping and sealing could be increased by thermal lamination with WPI films, which improves the stretchability and heat sealability of DMM films.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.207-215
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• 2023

This study was compared the soil environment and growth and yield of onion (Allium cepa L.) treated with non-mulching (NM) and mulching polyethylene film (PEF) and two biodegradable films (BFI and BFII) commonly used in farmhouses. Visual observation confirmed the degradation of BFI and BFII films after 150 days after tansplanting (DAT). BFII increased light penetration into the films and reduced the weight maintenace after 180 DAT, with a high decompostion at 30 days after soil tilling. Soil moisture contents much fluctuated between -14 kP and - 0 kPa in NM plots, increasing the minimum soil temperature of BFI plots. Mulching treatments decreased soil organic matter contents but did not subtantially increase soil mineral nutrients, soil bulk density, and number of bacteria compared to those of NM plots. Onion root growth was increased by PEF and BFI treatments at an early growth stage, 60 DAT, with the most remarkable stem extension observed for PEF and BFI treatments after 150 DAT. PEF and BFI treatments increased the bulb's diameter, length, weight, and lodging at 180 DAT. BFI treatments exhibited a high portion of the "very large" category producing with 55.3 tons ha^-1 based on the classification into bulb size, followed by PE (49.3 tons), NM (9.4 tons), and BFII treatments (2.7 tons) at 230 DAT.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1381-1387
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• 1998

Laminated films were prepared by casting corn-zein and fatty acid mixed solutions onto ${\kappa}-carrageenan$ films, and the effect of various fatty acids with different concentrations on the film properties such as water vapor permeabilities (WVP), tensile strength (TS) and elongation was investigated. WVP of the film decreased as concentration of fatty acids increased, and the lowest WVP value $(0.497\;ng\;m/m^2\;s\;Pa)$ was achieved with laminated films containing 30% lauric acid/corn-zein. The TS of laminated edible film seemed to decrease as the concentration of fatty acids increased, and TS of the laminated film was the highest (36.21 MPa) when the film contained 10% oleic acid. Weight loss of the minced mackerels packaged with corn-zein/carrageenan film which did not contain fatty acid was 11.7%, but weight losses of the samples packaged with oleic acid and lauric acid were 6.97% and 0.81%, respectively, after 30 days storage at $-20^{\circ}C$. The laminated films had an effect on preventing oxidation of the minced mackerels during storage because of high oxygen barrier property of the film. All of the minced mackerels packaged with the laminated films greatly reduced the peroxide value (POV) compared with unpackaged minced mackerels during storage. Also, thiobarbituric acid (TBA) values of the minced mackerels packaged with the laminated films were lower than that of unpackaged minced mackerels during storage.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.172.2-173
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• 2003

단백질, 탄수화물, 유지 등과 같은 생고분자를 소재로하여 제조하는 가식성 또는 생분해성 필름은 식품표면을 코팅하거나, 식품의 내부에 사용하여 식품을 외부의 충격으로부터 보호하고 식품의 저장수명을 증가시키는 동시에 수분, 기체 및 용질의 이동을 방지하는 기능을 한다. 이러한 가식성 필름의 소재 중 하나인 전분은 비교적 저가의 재료이고 기체투과를 방지하는 성질은 우수하지만, 탄력성이 적은 단점을 가지고 있다. 생고분자필름의 물리적 강도를 증진시키고 수증기의 투과성을 낮추는 방법으로 단백질과 탄수화물을 복합적으로 사용한다 본 실험에서는 분리 대두 단백질(SPI)과 옥수수 전분을 혼합하여 가식성의 생분해성 필름을 제조하고 이들의 이화학적 특성에 대해 연구하였다. SPI 필름은 SPI 5g에 증류수 100$m\ell$을 가해 glycerol 2g을 첨가해 제조하였으며, 옥수수 전분필름은 옥수수 전분 6g에 증류수 100$m\ell$을 가해 glycerol 1.2g을 첨가해 제조하였다. SPI와 옥수수 전분의 혼합필름은 SPI와 옥수수 전분의 양을 1：1 비율로 혼합하여 제조하였다. SPI 필름, 옥수수 전분 및 SPI와 옥수수 전분 용액의 혼합필름의 각각의 수증기 투과도는 7.49$\times$$10^{-11}$, 2.69$\times$$10^{-11}$, 4.24$\times$$10^{-11}$ g.m/m$^2$.s.Pa이었다. 본 실험으로 SPI의 단일재료로만 필름을 제조하였을 때보다 SPI 용액에 옥수수 전분용액을 혼합해 필름을 제조하면 탄력성을 유지하면서 수증기 투과도를 낮출 수 있다는 결과를 얻을 수 있었다.현미밥의 유리아미노산 분석 결과 필수아미노산을 포함한 다량의 아미노산이 존재하였으며 혈압강하 기능성 성분인 GABA(${\gamma}$ -amino butyric acid) 함량은 현미가 4.7 mg/100 g, 발아현미 20.8 mg/100 g이었으며, 동결건조 후 분석한 발아현미밥의 GABA 함량은 5.7 mg/100 g이었다. 발아현미밥의 관능검사 결과는 색, 윤기, 맛, 부착성, 응집성, 탄력성이 A가 유의적으로 높았으며, 외관의 경우도 A가 더 높은 평가를 받았다. 또한 전반적으로 A가 B에 비해 유의적인 차이를 나타내진 않았지만 더 나은 선호도를 나타내었다.좋게 평가되었다.＊값은 63-68사이로, a＊값은 0.13에서 -0.89사이를 b＊값은 2-5값 사이에서 변화하여 제조한 죽의 색이 옅은 황색임을 알 수 있었다. 고형분 함량, 퍼짐성과 pH에 대한 $R^2$은 각각 0.4280, 0.5433과 0.2406임을 볼 때 버섯, 당근, 대파의 비율에 따라 제조한 쇠고기 야채 쌀죽의 고형분 함량, 퍼짐성과 pH는 설정된 범위내에서 그 유의성이 인정되지 않아 큰 영향을 미치지 않음을 알 수 있었다. 관능검사 결과, 색과 향에 대한 반응표면 회귀식의 $R^2$은 각각0.6000과 0.7825이고 P-value는 각각 0.4290과 0.0942로서 5% 수준에서 유의한 상관성이 없음을 확인할 수 있었다. 맛과 점성에 대한 $R^2$은 0.8717과 0.8068이고 P-value는 각각 0.0195 (p ＜0.05)와 0.0612로서 야채의 배합비에 따라 맛에 있어서 유의확률 5%수준에서 그 유의성이 인정되었으며, 전체적인 기호도에 대한 유의성은 $R^2$이 0.8463이고 P-value는 0.034

• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.121-125
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• 1998

1977년 polyacetylene(PA)이 할로겐 도핑에 의해 금속에 필적하는 도전성을 나타낸다는 것이 발견된 이래 전도성 고분자는 전기 전도도 및 전자 상태를 자유롭게 제어 할 수 있다는 특징 때문에 2차 전지 및 연료 전지, 가스분리막, 우주 항공용 경량 도전재료, 대전방지제등의 넓은 응용분야를 가지며 현재에도 기초 연구 및 응용 연구의 양면에서 활기를 띠고 있다.(중략)