• 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.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.449-457
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• 1995

Aseptic packaged cooked rice without oxygen absorber and EVOH material was not suitable for good quality during long storage at room temperature. Quality change of aseptic packaged cooked rice with OPP/EVOH/EPL(P-1), PET/EVOH/EPL(P-2) and OPP/EVOH/LLDPE(P-3) for lid material and FX and TSQ for oxygen absorber was observed during storage(60 days) at $20^{\circ}C,\;30^{\circ}C\;and\;40^{\circ}C$. To evaluate quality change of aseptic packaged cooked rice, water content, color, pH, acidity, hardness, and total plate count were measured periodically. The results showed that moisture content was decreased as storage time increased while storage temperature showed no significant effect. P-2 and FX combination had the lowest evaporation of water. L value was decreased as storage time increased while a value increased in all treatment. P-2 and FX combination had the best result for color value. Titratable acidity and pH of P-3 increased up to 20, 5.5, respectively at the end of storage while the other treatment showed no significant effect. Hardness of aseptic packaging of cooked rice was decreased as temperature of storage increased while lid materials and oxygen absorber types showed no significant effect. Result of total plate count showed that there was no detection for $20^{\circ}C\;and\;30^{\circ}C$ storage temp. while more than $1{\times}10^6\;CFU/g\;for\;40^{\circ}C$ storage temp. at the end of storage. In conclusion, aseptic packaged cooked rice could be stored and distributed for 6 month at room temp. and effect of lid materials on quality change of aseptic packaged cooked rice was more significant than oxygen absorber.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.175-182
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• 2022

Heavy metals can be intentionally or unintentionally introduced into plastic food utensils, containers, and packaging (PFUCP) as additives or contaminants, which can be ingested with food by humans. Here, seven-heavy metals (lead, cadmium, nickel, chromium, antimony, copper, and manganese) with toxicity concerns were selected, and risk assessment was done by establishing their migration from 137 PFUCP products made of 16 materials distributed in Korea. Migration of heavy metals was examined by applying 4% acetic acid as a food simulant (70℃, 30 minutes) to the PFUCP products. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the analysis of migrated heavy metals, and the reliability of quantitative results was confirmed by checking linearity, LOD, LOQ, recovery, precision, and expanded uncertainty. As a result of monitoring, heavy metals were detected at a level of non-detection to 8.76 ± 11.87 ㎍/L and most of the heavy metals investigated were only detected at trace amounts of less than 1 ㎍/L on average. However, antimony migrated from PET products was significantly higher than other groups. Risk assessment revealed that all the heavy metals investigated were safe with a margin of exposure above 311. Collectively, we demonstrated that heavy metals migrated from PFUCP products distributed in Korea appear to be within the safe range.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.63-69
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• 2015

The aim of this study was to investigate the deformation of packaging materials used for ready-to-eat (RTE) foods after the retort process and microwave heating. From the multilayer films consisting of polyethylene terephthalate (PET), polyamide (PA), and cast polypropylene (CPP) in a stand-up pouch form used for RTE foods, some deformation of the CPP layer, which was in direct contact with the food, was observed after the retort process and microwave heating. The damage was more severely caused by microwave heating than by the retort process. This may be attributed to diverse factors including the non-uniform heating in a microwave oven, the sorption of oil into the packaging film, and the different characteristics of food components such as viscosity, salt and water content. The development of heat-resistant packaging materials and systems suitable for microwave heating of RTE foods is required for the safety of consumers.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.368-374
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• 1999

This study was designed to investigate effects of pulsed electric field (PEF) treatment on physiological changes of microbial cells, using domestically fabricated pilot scale PEF device. The effect of non-thermal PEF treatment on physiological characteristics of microorganisms was determined by salt resistance, the amount of UV absorbents, cell staining, recovery rate of defected cells, and changes in structure of cell membrane. Salt resistance of Escherichia coli, Bacillus subtilis and Rhodotorula minuta was examined after PEF treatment at 40 kV/cm, 84 pulse, $10{\mu}s$ pulse duration. Approximately $1\;log_{10}$ cell number of viable microorganisms was decreased by addition of salt. PEF treatment significantly increased the amount of UV absorbents at 260 and 280 nm because of leakage from damaged cell membrane by PEF treatment. Although three kinds of microorganisms treated by PEF were difficult to be observed due to their cell membrane damage, untreated cells were clearly observed by a microscope. PEF-treated R. minuta was not stained by methylene blue due to cell membrane defect. When E. coli, B. subtilis and R. minuta were cultured after PEF treatment, they showed 5, 4, and 8 hr longer lag phase, respectively, compared to control, but growth rates were not affected.

• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.460-465
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• 2008

This study examined the effect of head formation on the quality maintenance of minimally processed lettuce (Lactuca sativa L.) samples. The fresh-cut lettuce samples were packed in $20{\times}15{\times}5$ cm polypropylene+polyethylene terephthalate tray, and were then stored at $4^{circ}C$ for up to 8 days. According to the results, the sample with 100% head formation had lower sugar, minerals (Ca, Na, Fe, Mg, K), and chlorophyll contents compared to the sample with 70% head formation. The 70% head formed lettuce had higher vitamin C content at 3.30 mg/100 g, whereas the 85% and 100% formed samples had lower levels of 2.61 and 2.10 mg/100 g, respectively. The polyphenol oxidase (PPO) activity of the 70% formed lettuce was 240 unit/g, while the 100% formed sample had almost 2-fold higher activity. However, the 100% formed lettuce had greater firmness than all other samples. Overall, among the fresh-cut lettuces, the sample with 70% head formation showed more positive effects in terms of quality maintenance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.4
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• pp.643-648
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• 1996

The changes in hydration of brown rice, Chu-chung byeo(Japonica type) were determined during storage at different storage temperatures($4^{\circ}C$, 2$0^{\circ}C$, 3$0^{\circ}C$ and 4$0^{\circ}C$) in a 4-layered laminated film pouch(PET 12${\mu}{\textrm}{m}$/AI-foil 7${\mu}{\textrm}{m}$/o-Nylon 15${\mu}{\textrm}{m}$/L-Mix100${\mu}{\textrm}{m}$). At the beginning of storage, the hydration rate of brown rice increased with higher soaking temperature, and the activation energy of hydration was 10.3kcal/mole. Water diffusion coefficient of brown rice due to storage temperature during storage at 3$0^{\circ}C$ of soaking temperature was decreased by the elapse of storage periods and increment of storage temperature(below 3$0^{\circ}C$). ).

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.5
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• pp.64-72
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• 2007

This study investigated the types, forms, and origination of litter found along one hiking course in Moaksan Provincial Park, 'Jungin-ri Course'(entrance-ridge-valley-peak). In addition, a survey was conducted to understand hikers' litter control awareness in order to determine possible backcountry litter control measures. The following are the results of this study: 1. For the litter Sequency investigation, 199 recyclable pieces of litter were found on the mid-slope(61.6%), 89 by the entrance(27.6%), 19 in the valley(5.9%) and 16 on the peak(4.9%). A total of 323 pieces of litter were found. Paper materials were the most common, followed by plastic containers such as PET bottles and yogurt containers. Of particular interest, 288 papers and cans were found on the mid-slope(46.9%). By the entrance, more plastics and bottles were found. 2. There were 614 pieces of flammable litter collected and only 19 pieces of non-flammable. Most of the flammable litter, including snack pacts, plastic bags, processed lumber, cigarette butts, tissues, cigarette boxes, and fabric was found on the mid-slope. 3. Very little food waste was found throughout the whole site proving that the policy prohibiting hikers from cooking and eating at the designated sites has been effective. However, food waste is difficult to find because it naturally decays with time. 4. $X^2$-test was used to find different types of litter and their verified origination frequency. It was found that recyclable litter, and food waste took about 1%. In addition, recyclable litter, especially bottles, was found relatively frequently by the entrance. Flammable litter was found most often at the peak. 5. The questionnaire results showed that 48.2% of the respondents "shorten their hiking journey and purchase food outside the entrance" and 29.6% said that they "bring a packed meal from home". Only 8.2% said that they "cook something when an appropriate location is found". At the Jungin-ri course, a few hikers brought their own food to eat or cook, but most hikers purchased something to eat onsite. 6. The results of the question about having experience littering while hiking showed that 19.3% litter and 79.2% do not. Those that responded "yes" gave various reasons for littering. 63.6% claimed, "there are no designated trash containers". 15.9% said they litter subconsciously. Finally, 3.2% insist that they litter "because food naturally decomposes". 7. As a result of the overall satisfaction according to the Likert scale and the analysis with an average of 14 variables, it was found that the average "toxic litter control convenience" was 2.41 with very low satisfaction. Thus, the results indicate the importance of providing appropriate back country litter control facilities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.2
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• pp.149-157
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• 1988

This study was carried out to prepare the flavoring substance using sardine for instant soup, and to examine the taste compounds and storage stability of the product. In preparation of product, raw sardine are gutted, boiled for 10 minutes and smoked 3 times to $9{\sim}10%$ moisture content at $80^{\circ}C$ for 8 hours. The smoked-dried sardine meat were followed to be 50 mesh of particle size. The powdered-dried sardine were mixed 4.0% sugar, 20.0% table salt, 3.0% monosodium glutamate, 0.2% black pepper, 0.2% garlic powder and 0.2% onion powder, Finally the powdered instant soup product were vacuum packed in a laminated film(PET/A1 foil/CPP) bag, and then stored at room temperature for 120 days. The effect of smoking on enhancing flavor and on preventing lipid oxidation of product during storage were observed. From the chemical analysis and omission test, the principal taste compounds of product were IMP, 478.2mg/l00g; free amino acids such as glutamic acid, histidine, arginine, phenylalaine 3292.5mg/l00g; non-volatile organic acids such as lactic acid, ${\alpha}-ketoglutaric$ acid, 712.2mg/l00g; total creatinine 409.0mg/100g, and small amount of betaine, TMAO. Fatty acid composition of product were mainly consisted of polyenoic acids such as 20:5, 22:6, followed by saturated acids, monoenoic acid. The major fatty acid were 16:0, 16:1, 18:1, 20:5 and 22:6. From the results of sensory evaluation and chemical experiments during storage, the vacuum packed product were good condition for preserving the quality during storage for 120 days. We may conclude that the quality of present product was not inferior to that of seasoning powder of anchovy on the market, and it can be commercialized as a flavoring substance in preparing soup and broth.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.264-270
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• 2021

In this study we investigated the elution level of lead (Pb), cadmium (Cd), arsenic (As), zinc (Zn), nickel (Ni), antimony (Sb), germanium (Ge), aluminum (Al) and hexavalent chromium (Cr⁶⁺) from 69 home-cooking utensils into a food stimulants. The results of migration testing according to the Korea standards and specifications for utensils, containers and packages showed values the allowable migrantion limits. Al was detected in all 7 utensil materials with the average concentration ranging from 0.002-5.989 mg/L. According to the migration conditions for (180℃, 30 min), the average concentration of Al in paper was 7.2 times higher than 25℃, 10 min (P<0.05). The results of migration testing at 180℃, 30 min were also below the allowable migrantion limits. When comparing with the provisional tolerable weekly intake (PTWI) of Al, the estimated weekly intakes (EWI) accounted for 0.000-0.045% for Al.