• Food Science and Preservation
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• v.11 no.2
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• pp.135-141
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• 2004

To examine the quality changes of tomato and plum fruits during storage under various storage conditions, the rate of weight loss, pH change, titratable acidity, Hunter a value, firmness, and anthocyanin content were determined during storage. Tomato and plum fruits were stored at 4$^{\circ}C$ and 25$^{\circ}C$. Tomato fruits were packaged with high density polyethylene film (HDPE) and polyvinylidene chloride film (PVDC), and plum fruits were packaged with HDPE. Tomato fruits packaged with PVDC and plum fruits packaged with HDPE at 4$^{\circ}C$ were the most desirable in terms of weight loss. Titratable acidity of tomato fruits decreased with increasing storage time regardless of temperature and packaging method. Hunter a value of tomato fruits stored at 25$^{\circ}C$ increased regardless of packaging method, while it was not changed for tomato fruits stored at 4$^{\circ}C$. Firmness of plum fruits stored at 25$^{\circ}C$ significantly decreased during storage and anthocyanin content increased. Microbial numbers of tomato fruits increased during storage, but its rate was retarded during storage when tomato fruits were packaged with HDPE and stored at 4$^{\circ}C$. These results suggest that cold chain system and appropriate packaging could maintain the quality and prolong the shelf life of fresh produce.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.465-468
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• 2006

This paper investigates the effect of curing conditions on the strength improvement of polymer-modified mortars using epoxy resin with various curing methods. The polymer-modified mortars using epoxy resin are prepared with various polymer-cement ratios, and subjected to standard, hot water, heat cure and autoclave cures. The epoxy-modified mortars are tested for flexural and compressive strengths at desired curing methods. From the test results, the flexural and compressive strengths of the epoxy-modified mortars are hardly improved by the autoclave and hot water cures compared to the ideal cure of $20^{\circ}C$. Among the four types of curing methods, the strengths of the heat cured epoxy-modified mortars is largely improved. Especially, it is obtained in the mortars sealed with PVDC film.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.113-122
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• 2002

Beef loins that retailed in market were used as experimental samples. Some beef samples in raw state were packaged with PVDC as aerobic and vacuum condition. The other beef samples were cooked until core temperature arrived at 70$^{\circ}C$ and then packaged immediately in the same way of raw samples. After these samples were irradiated by electron beam 6kGy, irradiated samples were stored in refrigerator(2～4$^{\circ}C$). Identify and quantity of cholesterol oxides were analysed stored at 0 and 7 days, respectively. During the early stage of storage, 7$\beta$-hydroxycholesterol and 7-ketocholesterol were respectively produced from the raw meat samples, and the production of these chemicals were significantly higher (P$<$0.05) from the meats with aerobic packaging than those with vacuum packaging. With the passage of storage time, 7$\alpha$-hydroxycholesterol, 20$\alpha$-hydroxycholesterol, $\beta$-epoxide, $\beta$-epoxide and some other chemicals, which were not produced during the early stage of storage, were produced, Also, the production of these chemicals were significantly increased (P$<$0.05) with the passage of storage time. Cooked meat after irradiation and irradiated meat after cooking produced cholesterol on the 7th day of storage, although this chemical was not produced during the early stage of storage. Production of cholesterol oxides was significantly increased (P$<$0.05) with the passage of storage time for all treatments, and showed significantly lower value (P$<$0.05) with the vacuum packaging than aerobic packaging. Summarizing the aforementioned results, it was found that the production of cholesterol oxides was more easily affected by packaging condition than irradiation.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.74-82
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• 1999

Beef, pork and chicken meat that retailed in market were used as experimental samples. Some samples in raw state were packaged with PVDC as aerobic and vacuum condition. The other samples were cooked until internal temperature arrived at $70^{\circ}C$ using electric oven and then packaged immediately in the same way of raw samples. After these samples were irradiated by electron beam (0, 1, 2 kGy), irradiated samples were stored in refrigerator $(2{\sim}4^{\circ}C)$. Identification and quantification of cholesterol oxides were analysed at 0, 7, 14 days. The results were following. The results indicated that raw-vacuum packaged lower detected than that of other treatments. In raw-vacuum packaged, the amounts of $7{\beta}-hydroxycholesterol$ were detected slightly $(below\;0.5\;{\mu}ug/g)$ during storage, and 7-ketocholesterol were detected during every stored time and amounts of this detection were $8.02{\sim}101.30\;{\mu}g/g$. In cooked-aerobic packaged, total amounts of detection were higher than that of other treatments, total amounts of cholesterol oxides were detected about $51.18{\sim}155.90\;{\mu}g/g$ during storage. In all results, pork and chicken samples were similar to the results of beef samples. In all results, total amounts of cholesterol oxides increased significantly as irradiation dose and storage time increased (P<0.05).

• Korean Journal of Food Science and Technology
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• v.44 no.1
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• pp.48-54
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• 2012

This study was conducted to improve the packaging technology used for Gangjung and the product's quality characteristics during storage. Packaging materials consisting of (1) IP: OPP (oriented polypropylene)/PE (polyethylene) + Paper, (2) LP1: OPP/PE + Paper, (3) LP2: OPP/PE + Can, (4) LP3: OPP/PE + Plastic, (5) BP1: OPP/PE, (6) BP2: OPP/DL/CPP (cast polypropylene), (7) BP3: PET/PE/CPP, and (8) BP4: OPP/PVDC (polyvinylidene chloride)/PE/CPP were used. The major fatty acids including 54.2% linoleic acid, 24.1% oleic acid, 11.2% palmitic acid and 6.0% linoleic acid were assessed. The packages effective in maintaining moisture were in the order of LP2, BP4 > IP > LP3, BP1, BP2 > LP1 > BP3. There were no significant differences in water content and the products in IP, BP3, and BP showed the highest level in the increase in hardness on day 60 of storage. Acid values of IP, LP1, LP2, LP3, BP1, and BP2 were maintained at <2.0 during 40 days of storage. IP, LP1, LP2 and BP1.

• Journal of Life Science
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• v.12 no.1
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• pp.8-15
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• 2002

In this paper we dealt with processing of sausage using duck mechanically deboned meat(duck-MDM). The results may be summarized as follows : 1) after semi-thawing of freezing duck-MDM at $25^{\circ}C$ for 3 hours and cutting as thin, 2) alkali washing at low temperature for 4 hours by 0.2% NaHCO$_3$and 0.15% NaCl, 3) curing at low temperature for 4 hours, 4) after washing and dehydrating(moisture 80%), 5) grinding at low temperature for 55 minutes by silent cutter such as 1st grinding for 10 minutes added only dehydrated meat, 2rd grinding for 30 minutes added salt in 1st grinded meat and 3rd grinding for 15 minutes added other additives, 6) after quick casing in PVDC film and heating at 9$0^{\circ}C$ for 80 minutes, 7) cooling to below room temperature. The additives added at 3rd grinding process were Polymix-CA(0.3%), Polymix-CS(0.3%), polyphosphate(0.3%), sugar(4.2%), potato starch(8.0%), pyre-phosphates(0.3%), isolated soy protein(7.0%), MSG(0.2%), onion powder(0.5%), garlic powder(0.1%), nutmeg (1.5%), potassium sorbate(<0.1%), food red no.40(0.0075%), egg albumin(7.0%) and gluten(3.0%).

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.94.2-94.2
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• 2011

In this work, multi-functional groups, i.e., nitrogen and oxygen, contained microporous carbons (MF-MCs) were prepared by the one step carbonization of the poly(vinylidene chloride-co-acrylonitrile-co-methyl methacryalte) (PVDC-AN-MMA) without activation. The electrochemical performance of MF-MCs was investigated as a function of carbonization temperature. It was found that MF-MCs had a high specific surface area over $800m^2/g$ without additional activation, resulting from the micropore's formation by the release of chlorine groups. In addition, although functional groups decreased, specific surface area was increased with increasing carbonization temperature, leading to the enhanced electrochemical performance. The pore size of the carbon distributed mainly in small micropore of 1.5 to 2 nm, which was idal for aqueous electrolyte. Indeed, the unique microstructure features, i.e. high specific surface area and optimized pore size provided high energy storage capability of MF-MCs. These results indicated that the microporous features of MF-MCs lead to feasible electron transfer during charge/discharge duration and the presence of nitrogen and oxygen groups on the MF-MCs electrode led to a pseudocapacitive reaction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.3
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• pp.35-44
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• 1993

The objective of this study is aimed at developing a new class of polymer concrete, in which hydration of cement and curing of a thermosetting resin can take place simultaneously during the mixing of concrete components. For the selected mix-proportion of the new polymer, the physical and mechanical properties needed for designs are presented. These important properties are compressive strength, flexural strength, split tensile strength, direct strength, fatigue characteristics and fracture parameters. The observed properties are always compared with conventional concrete to serve as reference for engineer in deciding or selecting the proper materials for their projects, and shore protecting structure.

• Food Science of Animal Resources
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• v.21 no.3
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• pp.235-245
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• 2001

This study was conducted to evaluate the usefulness of Second-Heat-Seal film(SHS) as an alternative material to PVDC/EVA shrink film(VSP) being currently used by domestic meat packer for vacuum-packaging of fresh meat. The samples from pork loin and beef striploin and round were stored at 2$^{circ}C$ for 5 weeks and measured for the changes of microbial counts, color, pH, volatile basic nitrogen(VBN), purge loss and sensory parameters. The pork loins packed with SHS showed higher spermine contents during the whole storage period at 2$^{circ}C$, and lower counts in total microbes and lactic acid bacteria after 28 days storage at 2$^{circ}C$ than those packed with SHS tended to be lower than those packed with VSP over the storage time. Nevertheless, no significant differences were observed between two packaging treatments in the other quality parameters evaluated. It is therefore concluded that SHS film might have a possibility to substitute for VSP film for vacuum-packaging of fresh meat at least from a materials point of view.

• Food Engineering Progress
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• v.14 no.4
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• pp.354-358
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• 2010

The methods for determining the diffusion parameters for the diffusion of d-limonene, a major volatile compound of orange juice, through a multi-layered food packaging material and predicting its absorption into the packaging material have been investigated. The packaging material used was the 1.5-mm thick multi-layered packaging material composed of high impact polystyrene (HIPS), polyvinylidene chloride (PVDC), and low density polyethylene (LDPE). Orange juice was placed in a cell where volatiles were absorbed in the sample package and kept at $23{\pm}2^{\circ}C$ for 72 hr. The d-limonene absorbed in a 1.5-mm thick multi-layered food packaging material was analyzed by a solid phase micro-extraction (SPME). The absorption parameters for the absorption of d-limonene in the packaging material were determined and absorption of d-limonene into the packaging material was predicted using absorption storage data. The SPME desorption at $60^{\circ}C$ for 1 hr resulted in the most sensitive and reproducible results. The diffusion coefficients of d-limonene in the packaging material and the partition coefficient at $23{\pm}2^{\circ}C$ were approximately $1-2{\times}10^{12}m^2$/s and 0.03, respectively. The absorption profile no earlier than 30 hr was fit well by a model derived from the Fick's law.