• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.3-13
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• 2005

This study was conducted to investigate the changes in some physicochemical properties of Codonopsis lanceolata cultivated on a wild hill, which were packed with woven polypropylene (WP) or low density polyethylene (LDPE, thickness 0.04 mm) bags and stored at $4^{\circ}C$ or $20^{\circ}C$ for 30 days. Those characteristics of fresh samples were as follows. pH : 5.3, moisture and ash content $86\%$ and $5.5\%$ respectively, Ca, Mg, Na and K content Per Ins dry matter : 427.3mg, 203.4 mg, 10.2mg, 619mg, respectively and crude saponin and codonoposide : 29.7mg and 3.82mg. Among the physicochemical properties, the pH, color parameters and Ca and Mg contents decreased or changed significantly during the storage period, but the content of crude saponin and codonoposide were almost maintained as a fresh sample for 30 days except for the condition of the WP packaging and room temperature. We could conclude that both of the LDPE packaging and chilled conditions were necessary for the best storage of Codonopsis lanceolata cultured on a wild hill for a long time.

• Food Science and Preservation
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• v.16 no.2
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• pp.179-185
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• 2009

To develop an Enoki mushroom packaging method, mushrooms were stored at $1^{\circ}C$ for 12 days after passive MAP packaging(PM), vacuum packaging(VM), and gas flushing packaging(AM), after investigation of film thickness influences on respiration rates and gas compositions(LDPE films 20, 40, and 60 m in thickness were tested). Enoki mushrooms had respiration rates of 26.4 mL $CO_2/kg/hour$ at $0^{\circ}C$, 80.0 mL $CO_2/kg/hour$ at $10^{\circ}C$, 130.9 mL $CO_2/kg/hour$ at $20^{\circ}C$, and 130.9 mL $CO_2/kg/hour$ at $30^{\circ}C$. A film thickness of 20 m was chosen for further tests to maintain the oxygen concentration above the minimum growth level; the thinnest film offered a higher gas transmittance rate than did the thicker films. No anaerobic respiration was evident over 12 days of storage using any packaging method, with the exception of VM. AM, using a high concentration of $CO_2$, restricted respiration rate. Mushrooms packaged using the VM method showed the greatest weight loss and extent of discoloration among the packaging methods tested, followed by AM mushrooms using 50% $CO_2/10%\;O_2/40%\;N_2$. Mushrooms packaged by the VM and PM methods developed a serious off-flavor after 2 days of storage, and a high stipe elongation rate after 5 days of storage, respectively. However, AM using 50% $CO_2/10%\;O_2/40%\;N_2$ of various gas ratios tested, allowed Enoki mushrooms to be maintained for up to 12 days without development of off-flavor, discoloration, or moldiness.

• Food Science and Preservation
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• v.9 no.2
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• pp.121-125
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• 2002

Cherry tomato was packed with several plastic films, and investigated the quality characteristics such as gas composition, weight loss, microbial load, soluble solid content, total acidity during storage at 12$\^{C}$. Cast polypropylene(CPP), low density polyethylene(LDPE), polyolefin(MPD, PD961) and perforated polyolefin(PY85) were used as packaging film. Oxygen and carbon dioxide concentration inside packages generally showed a stabilized levels after 10 days, but those of CPP and PD961 changed throughout the storage. Weight loss of PY85 was 25.6 % after 20 days, while others maintained around 1.0%. Total microbial count showed a increase pattern similar to yeast and mold, and CPP maintained the highest microbial load after 10 days. MPD retarded the decay of cherry tomato to 5.3%, while others showed above 20% after 20 days.

• Korean Journal of Food Science and Technology
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• v.31 no.5
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• pp.1289-1294
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• 1999

To identify the effect of packaging film on browning reaction of dried squid, 3 kinds of packaging film$(NYLON\;12\;{\mu}m/LDPE\;80\;{\mu}m)$ including transparency, white, black film were tested about browning degree of dried squid during storage at ambient temperature for 50 days. During storage period, water content and water activity were maintained almost constant, and microbial count was not changed. When color index was measured by color difference meter, L value and ${\Delta}E$ value were the highest in the dried squid packaged with transparency film. ${\Delta}E$ value was rapidly increased in early packaging period(within 10 day). TBA value was showed same tendency with ${\Delta}E$ value in early storage period. So, the browning was supposed to originated from lipid oxidation by UV light transmitted through packaging film in the early storage period.

• Journal of the Korean Applied Science and Technology
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• v.34 no.3
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• pp.478-486
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• 2017

To find the effect of packaging materials(LDPE $60{\mu}m$, Ceramic $30{\mu}m$ and $60{\mu}m$) to enhance the shelf-life of de-astringent persimmon, the fruits used were the astringent persimmons of "Cheongdobansi" and astringency was removed in $CO_2$. De-astringent persimmon were stored in MA for 140 days at $5^{\circ}C$. During storage, the concentration of oxygen was decreased to 5.2%, while the concentration of carbon dioxide was increased to 5.2% from 18 days. But the concentration of oxygen and carbon dioxide was maintained at a constant concentration until the end of storage. The rate of weight loss was gradually decreases for the storage time elapsed and has better in ceramic $60{\mu}m$ packaging than other packaging materials. Fruit hardness and color value were well maintained in ceramic $60{\mu}m$ packaging. Tannin content and soluble solid were not significant difference among the packaging conditions. Ethanol and acetaldehyde content were decreased during early period of storage and then increased. As a result of objective analysis, de-astringent persimmon storage in ceramic $60{\mu}m$ was more effective than other storage conditions.

• Korean Journal of Food Science and Technology
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• v.35 no.1
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• pp.149-154
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• 2003

Changes in mineral (Ca, Mg) contents and pectic substances of mature-green 'Nanko' Mume fruits hermetically packaged in 0.03 mm low density polyethylene (LDPE) films with and without gas absorbents were examined during storage at $25^{\circ}C$ for 10 days. Each packaging contained 10 g $Ca(OH)_2$ as a carbon dioxide scavenger, 30 g $KMnO_4$ as an ethylene scrubber or their mixture. In the presence of the ethylene scrubber, losses in mineral contents of alcohol insoluble solids and water soluble pectin were remarkably suppressed, whereas no significant difference was observed in the Ca content between the fresh fruit and those stored for 10 days. Fruits packaged with the ethylene absorbent retained higher amount of pectic substances than those with other packaging treatments. Degradation of the pectic substances into small molecules was also noticeably reduced when the ethylene scrubber was used. Overall results showed that the combination of the gas permeable film and the ethylene absorbent could be applied to mature-green Mume fruits as an effective packaging method to retard the texture softening during storage at the ambient temperature.

• International Journal of Highway Engineering
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• v.7 no.2 s.24
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• pp.1-12
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• 2005

This study was conducted to evaluate effect of geogrid and fabric, which are used underneath the overlaid asphalt pavement for retarding reflection cracking by simulated laboratory test. In this study, an interlayer at the interface between old concrete pavement surface and overlaid asphalt mixture, and polymer-modifier were used as an effort of retarding reflection crack initiation and for strengthening mixture. Five products were used in preparation of asphalt concrete beam specimen which was tack coated on top of jointed concrete block. Simulated Mode I and II fracture test were conducted under wheel loading and results were compared among those products. From the test results, several material and reinforcement combinations were observed to have a significant retardation effect against reflection cracking. The most effectively strengthened pavement against reflection cracking was found to be the LDPE-modifier asphalt mixture with a grid reinforcement at the bottom.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.429-437
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• 1999

A mathematical model was established for estimating changes in pressure and volume of permeable kimchi packages. The model comprises the CO2 gas production from kimchi and permeation of O2, CO2 and N2 through the permeable film or sheet. Using the developed model, the effects of various packaging variables on the pressure and volume changes were analyzed for rigid and flexible packag es of kimchi(3% salt content) at 15oC, and then effect of storage temperature was also looked into. In case of rigid pack of 400g, using the plastic sheet of high CO2 permeability and initial vacuumizing can help to relieve the problem of pressure build up. The lower fill weight can further reduce the pressure, but will result in higher packaging cost. For the flexible package of 3 kg, highly permeable films such as low density polyethylene(LDPE) and polypropylene can reduce the volume expansion. Higher ratio of CO2 permeability to O2 and N2 permeabilities are effective in reducing the volume expansion. Increased surface area cannot contribute to reduction of volume expansion for highly permeable flexible packages of kimchi. For the impermeable packages, pressure and volume at over ripening stage (acidity 1.0%) increase with decreased temperature, while those at optimum ripening stage(acidity 0.6%) change little with temperature. Pressure of permeable rigid LDPE package increases with tem perature at any ripening stage, and temperature affects the volume of flexible LDPE package very slightly. Experimental verification of the present results and package design with economical consid eration are needed as a next step for practical application.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.15-24
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• 2005

We investigated the changes of volatile flavor components from Codonopsis lanceolata, which were packed in woven polypropylene(WP) film or low density polyethylene(LDPE) film and stored for 15 and 30 days at refrigerated($2{\∼}4^{\circ}C$ ) or room($18{\∼}20^{\circ}C$) temperature. A hundred and sixty seven volatile flavor components in the fresh C. lanceolata were identified by GC/MS analysis. When determining the flavor components from C. lanceolata cultivated on a wild hill and stored at 4 conditions for 30days, six volatile components such as 1-hexadecene, 2,6-dimethyl-2-octanol, 2-methyl-2-dodecanol, $\alpha$-guaiene, $\delta$-cadinene and trans-2-hexen-1-ol were detected as common components of all stored samples, and The types of common flavor components of C. lanceolata were different according to storage conditions. The numbers were 16 from refrigerated, 7 from room temperature stored, and 10 components from WP or LDPE packed conditions, respectively. The total peak area ratio of the major 10 compounds were $52.0{\∼}86.8\%$, and the percentage of trans-2-hexen-1-ol, which was the only common compound among the major 10 components, was the highest as $26.4{\∼}68.1\%$ The major flavor profile, describe by highly trained panel, were green, aldehydic, earthy and camphoreous. As the result from sensory evaluation, the freshness of C. lanceolata was maintained better by controlling storage temperature rather than selection of package materials. The best condition for characteristic flavor of C. lanceolata was packing with LDPE and chilling.

• 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.189.1-189
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• 2003

‘부유’단감은 국내에서는 일반화되어 있는 PE필름 밀봉 저장방식으로 과실의 호흡에 의해 산소농도의 감소와 이산화탄소의 증가로 호흡이 억제되고 이에 따라 노화가 지연됨으로 과실의 저장수명을 증가시키는 방식이며, 최적저장온도는 -0.5~$0^{\circ}C$라고 보고되고 있다. 이에 본 실험에서는 상온유통을 고려하여 2$0^{\circ}C$에서 0.03mm, 0.05mm LDPE필름으로 포장한 경우와 무포장한 경우를 비교하여, 중량, 수소이온농도, 가용성고형분, 경도를 측정하고 이를 외관품질검사 결과와 종합적으로 검토하였으며, 또한 환경기체조성의 범위를 설정하기 위하여 산소농도(1~5%), 이산화탄소농도(5~15%)를 독립변수로 중심합성계획법(central composite design)에 의해 3단계로 부호화하였고 산소소비농도, 이산화탄소 발생속도, pH 당도, 경도를 종속(반응)변수로 결과를 이용하여 독립변수와 종속변수간의 함수관계를 규명하며, 독립변수들의 값의 변화에 따라서 반응량(종속변수)이 어떻게 달라지는 가를 예측하며, 독립변수가 종속변수인 반응량을 최적화(Optimize) 하는가와 어떤 실험계획법을 쓰면 가장 좋은 정도를 얻을 수 있는지를 규명하고자 한다.