• 한국포장학회지
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• 제26권2호
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• pp.71-76
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• 2020

CO₂ concentration in kimchi package has emerged recently as a potential index of product ripening to be monitored or sensed in intelligent packaging. Considering that addition of CO₂ absorber into the flexible kimchi package changes behavior of its CO₂ concentration, ripening of kimchi in total acidity, package CO₂ concentration in partial pressure (P_CO2) and package volume at 10℃ were estimated by mathematical model for two size packages included with different CO₂ absorbers. In small size package containing 0.5 kg of kimchi, relatively less gas permeable low density polyethylene (LDPE) sachet of the absorber was found to give rise of P_CO2 linearly correlated with acidity at acceptable conditions of absorber amount and size. The levels of P_CO2 at optimum ripening were different with absorber amount. However, highly gas permeable microporous spunbonded film (Tyvek) sachet did not show the linear relationship except a condition of 1.5 g of CO₂ absorbent. In large size package containing 2.0 kg, absorber sachets of LDPE and Tyvek could give the linear relationship between product acidity and package P_CO2 but at different levels (P_CO2 of package with LDPE sachet: 0.46~0.79 bar, P_CO2 of package with Tyvek sachet: 0.00~0.75 bar). The P_CO2 at optimal ripening was found to be less variable with LDPE sachets than with Tyvek ones. Use of package CO₂ concentration as an indicator of kimchi ripening was shown to be possible on the limited conditions where the linear relationship between them is established or confirmed.

• 한국식품영양과학회지
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• 제28권2호
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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.

• 한국식생활문화학회지
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• 제22권2호
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• pp.167-175
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• 2007

This study was to investigate purchase of women for commercial kimchi. Survey was carried out by questionnaire method that is target on 322 female over 20 age in Seoul area. The results of the study was that the way they get kimchi of women answered that they make it by themselves(63.3%). The reason of purchasing is they do not have enough time to make it at their home(43.8%) and its good taste(56.8%) result in their purchase. In the degree of preference about package material, prefer polyethylene(39.6%). Also respondents prefer purchasing poggi kimchi(63.4%) among other different types of kimchi. The promotion facts of purchasing commercial kimchi shows a high score in cold chain system package and specific kimchi development.

• 한국포장학회지
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• 제27권1호
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• pp.35-40
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• 2021

Calcium hydroxide (CH) reacts with CO2 to produce moisture, and sodium carbonate (SC) reacts with CO2 in the presence of moisture. Using these different characteristics of these two reactants, a CH/SC mixture of CO2 absorber tuned for kimchi ripening to produce CO2 in a flexible package was selected. A ratio of CH:SC (1:2) in highly gas permeable microporous spunbonded film (Tyvek) sachet was found to be appropriate for delayed and consistent CO2 absorption useful for kimchi package. Addition of superabsorbent polymer (SAP) as moisture buffer was helpful for boosting the consistency of CO2 absorption. In a package of 0.5 kg kimchi at 10℃, the sachet consisting of 0.794 g of CH + 2.276 g of SC + 0.4 g of SAP suppressed its volume expansion and maintained a suitable range of CO2 partial pressure (PCO2) steadily inside. These optimal conditions may vary depending on the type and salinity of kimchi, storage and distribution temperature, and the material and area of the absorber sachet. This study showed a potential of mixture CO2 absorber to be tuned for CO2 producing packaged kimchi for the purpose of keeping consistent PCO2 at tolerable volume expansion.

• 한국포장학회지
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• 제22권3호
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• pp.41-47
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• 2016

This paper provides an overview of kimchi packaging technology, focusing on packaging materials, package design, and active/intelligent packaging technology for kimchi. From a packaging-material standpoint, although various materials have been used to ensure customer satisfaction and convenience, plastic is the most widely used material, in the form of bags, trays, pouches, and rigid containers. Additionally, recent efforts in the kimchi packaging industry have allowed companies to differentiate their products by using different packaging materials and technologies, while simultaneously improving product safety and quality. On the other hand, the biggest problem in kimchi packaging is excess $CO_2$ production, leading to package expansion and leakage. To alleviate this problem, the use of $CO_2$ absorbers, high $CO_2$-permeable films, and degassing valves, in addition to the use of different packaging systems, has been investigated. Active and/or intelligent packaging systems have been developed, to include active functions beyond simply inert, passive containment and protection of the kimchi product. However, most such approaches are not yet adequately effective to be useful on a commercial scale. Therefore, further studies are needed to resolve the limitations of each technology.

• 한국식품과학회지
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• 제32권6호
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• pp.1326-1330
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• 2000

김치발효중 기체조성변화가 숙성정도를 감지할 수 있는지 알아보기 위하여 배추김치를 플라스틱 용기에 일정량 충진하여 밀봉한 후 저장하면서 포장내 기체조성 변화를 조사한 결과, 김치발효중 포장내 기체조성은 $CO_2$ 발생으로 인하여 계속적으로 변화하였다. 김치 발효온도와는 무관하게 $O_2$ 농도는 지수적으로 감소하고 $CO_2$ 농도는 매우 특징적인 2단계 증가양상을 나타내었다. $CO_2$ 농도는 2차 단계에서 다시 증가함에 따라 김치의 pH는 비례적으로 감소하였다. 저장 온도와 계절별 원료 배추에 따라 김치 포장내 $CO_2$ 농도변화 속도가 다르며 최종 농도에 있어서도 상당한 차이를 나타내었다. 고온에서 발효된 김치일수록 포장내 $CO_2$ 농도가 더 높은 경향을 보였고 여름배추 보다 겨울이나 봄 배추로 제조한 김치에서 포장내 $CO_2$ 농도 및 발생속도가 더 높게 나타났다. 이러한 연구결과를 바탕으로 포장내 기체조성 변화를 이용한 김치의 숙성도 감지 가능성을 확인할 수 있었다.

• 한국식생활문화학회지
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• 제34권2호
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• pp.233-239
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• 2019

This paper presents a literature review on the active technologies to regulate the levels of carbon dioxide and oxygen in Kimchi packaging. In this study, laser-etched pouches and $O_2$ scavengers were used for Kimchi packaging, and the efficiency of each packaging technique to regulate the $CO_2$ and $O_2$ levels inside Kimchi packages was investigated. When Kimchi was packaged with a laser-etched pouch, the $CO_2$ concentration in the sample with a high gas transmission rate was less than that in other pouches (p<0.05), and a low $CO_2$ level had little effect on the expansion of the package volume. Kimchi treated with an $O_2$ absorber exhibited a significantly lower (p<0.05) $O_2$ concentration inside the packages relative to the control. A low $O_2$ concentration inside the Kimchi package effectively inhibited the growth of total aerobic bacteria and lactic acid bacteria, as well as yeasts and molds on Kimchi. These results suggest that $O_2$ absorbers have a positive effect on the microbial quality of Kimchi. Therefore, packaging in a laser-etched pouch and the use of an $O_2$ scavenger could provide a novel packaging material for regulating the $CO_2$ and $O_2$ levels during Kimchi packaging.

• 한국포장학회지
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• 제24권3호
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• pp.113-120
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• 2018

The one-way gas valve developed in this study was designed to prevent the breakage of packages from increased internal pressure, which is a problem in packaged Kimchi, and simultaneously reduce the outflow of the offodor release. The effect of the one-way gas valve on the headspace atmospheric compositions was investigated in the packaging system. The changes of atmospheric compositions and quality factors of Kimchi, such as $CO_2$ accumulation, pH, titratable acidity, and salinity, were measured during a 4-week storage period at $4^{\circ}C$. The Kimchi package with the one-way gas valve dramatically reduced pressure build-up in the pouch by allowing the controlled flow of gas to the atmosphere. In addition, the package design allows the possibility of controlling the gas generated from Kimchi by adjusting the viscosity of the open pressure control oil. The one-way gas valve did not affect the sensory characteristics of Kimchi products during the storage period. Furthermore, the deodorizing capability of the activated carbon contained in the one-way gas valve effectively reduced the off-odor of Kimchi products released along with carbon dioxide. The novel one-way gas valve is considered to be an active packaging system that can solve major problems of expansion and off-odor leakage in the packaging of Kimchi.

• 한국식품조리과학회지
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• 제27권1호
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• pp.63-73
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• 2011

Cabbage (Baechu) Kimchi in its truncated form was placed in four different packing materials, Ny/PE/LLDP, OPP/AL/PE, PP and PET, and quality changes were observed during storage. Changes in pH and total acidity showed an x-shaped cross-curve as pH decreased and total acidity increased during storage. PP tray showed the slowest change at $5^{\circ}C$ with time. The pH was initially 6.25, but decreased to 4.12~4.16 at 20 days, and total acidity showed a 4 to 4.8-fold increase after 20 days of storage compared to the initial value. During storage at $5^{\circ}C$, total bacterial count and lactic acid bacterial count rapidly increased after 4 days. The total bacterial quantity decreased after a period of time and there were differences according to packaging material; OPP/AL/PE packaging showed the most dramatic decrease. Change in microbial count mostly followed a similar pattern to that of total acidity for all packaging materials. Changes in the color of Kimchi liquid, when examined by color index in $L{\cdot}b$/a form, rapidly decreased over time, similar to pH. Small Ny/PE/PP and OPP/AL/PE packages of Kimchi were examined for changes in free volume inside the packaging. After 13 days of storage at $5^{\circ}C$, the volume was 243 mL, but storage at $20^{\circ}C$ resulted in a volume of 372 mL, a more than 1.5-fold increase in free volume. There were changes in the quality characteristics of small package Kimchi according to storage temperature and packaging material, and large changes in pH, total acidity, and microbial count were evident upon storage at $5^{\circ}C$ for 8 days, which was the optimum palatability period. Mostly, PP treatment showed the slowest quality changes upon storage at $5^{\circ}C$. However, due to small package Kimchi's fast consumption system, the appropriate choice of packaging material must consider the product's turnover ratio. Further, the varieties of small package Kimchi should be diversified according to different consumer preferences by offering Kimchi with different maturity levels. Further, since the leading consumer base ranges in age from the teens to thirties, the development of various products targeting such consumers is necessary.

• 한국식품과학회지
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• 제26권1호
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• pp.62-67
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• 1994

김치를 Ny/PE, Ny/CPP(PP tray+Ny/CPP cover), Cryovac BK-1, BK-4, PET/Al/PE film으로 포장하여 $5^{\circ}C$ (97%RH), $20^{\circ}C$ (76%RH)에서 저장 중 품질변화를 살펴보았다. 김치의 품질을 평가하기 위하여 포장내 가스조성, pH, 산도, 색도, 젖산균 수, 기호도를 기간별로 측정하였다. 포장내 가스조성은 PET/Al/PE film 포장김치가 저장초기에 산소농도가 높았고, 저장말기에 이산화탄소농도가 거의 100% 수준에 달하였다. Cryovac BK-1, BK-4로 포장된 김치는 발효가 진행되면서 이산화탄소농도가 증가하다가 가스투과성에 의한 이산화탄소의 방출과 외부공기의 유입으로 산소농도는 증가하고 이산화탄소농도는 감소하는 형태를 보였으며 저장말기까지 Ny/PE, Ny/CPP, PET/Al/PE와는 달리 포장의 팽배화 현상은 나타나지 않았다. pH 변화는 포장재질에 따른 차이가 크지 않았으나 Cryovac BK-1, BK-4가 저장중 다른 포장재질에 비하여 약간 낮은 pH를 나타냈으며, 산도는 약간 높았다. 저장중 김치의 색도변화가 포장재질에 따라 달랐으며, 포장재질별 젖산균수, 기호도 변화는 저장온도 모두에서 유의적인 차이가 없는것으로 나타났다. 이상의 결과를 종합하여 본 실험에 사용한 포장재질이 김치의 품질에 미치는 영향은 크게 다르지 않다고 여겨졌고, 저장 및 유통시 문제점인 팽배화현상을 방지하기 위해서는 현재 업체에서 사용하는 기체차단성이 높은 포장재보다는 상대적으로 이산화탄소의 투과도가 높은 포장재의 사용이 바람직하다고 사료된다.