• 제목/요약/키워드: modified atmosphere

검색결과 358건 처리시간 0.023초

MA 저장중 표고버섯 (Lentinus edodes)의 품질변화에 관한 연구 (Changes in Quality of Shiitake Mushroom (Lentinus edodes) during Modified Atmosphere(MA) Storage)

  • 김길환;이세은;김동만
    • 한국식품영양과학회지
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    • 제20권2호
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    • pp.133-138
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    • 1991
  • 생 표고버섯의 신선도 연장을 위한 연구로 두께(0.04mm-0.1mm)가 다른 PE 필름을 이용하여 표고버섯을 밀봉한 후 $2^{\circ}C$에서 60일간 저장하면서 품질변화를 조사하였다. 저장중 이취성분인 에틸알콜과 아세트알데히드 생성량은 PE 필름 두께에 비례하여 높은 값을 나타내었다. 중량 감소율은 저장 60일 경과후 0.06mm 밀봉구가 가장 낮았는데, 그 값은 같은 저장기간의 0.04mm 밀봉구의 중량감소율에 비해 1/2 정도의 낮은 값을 보였다. 한편 저장기간이 경과됨에 따라 표고버섯의 조단백질 함량이 증가하는 경향을 보였으며, 단백질의 전기영동 변화양상도 저장조건에 따라 그 차이가 뚜렷하였다.

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CA 및 MA저장이 수삼 및 홍삼의 색상 및 관능적 특성에 미치는 영향 (Effect of Controlled Atmosphere and Modified Atmosphere Storage on the Color and Sensual Properties of Fresh and Red Ginseng)

  • 전병선;박채규
    • Journal of Ginseng Research
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    • 제22권2호
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    • pp.82-90
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    • 1998
  • In order to stabilize the price of fresh ginseng by extension of seasonal variation and marketing structure, and to reduce the cost of production by works of intensive and short term, studies were carried out. As fresh ginseng of 4 years old by the MA and CA was stored for 12 week at 4$^{\circ}C$, samples were collected after every 1, 2, 3, 4, 6, 8, 12 weeks for processing red ginseng. Color and Sensual characteristics on ginseng steamed red for the quality evaluation are summarized as follows. For the time course of storage with red ginseng, which was processed from fresh one after various treatments, L and b values were decreased, however a value was increased. In particular, absorbance was step-wisely increased. Turbidity was somewhat increased, and non-treatment of preservative were shown 2 times higher of absorbance. Extraction ratio of ethanol-soluble extractives slightly increased by the preservation methods, and as storage period was passed. CA storage and preservative treat merit versus MA and non-preservative treatment gave much stability in ginseng quality. In the sensual characters, sour taste and sweet taste were increased, but fresh taste and rice scorched taste were decreased. Bitter taste was not much changed until end of storage. CA was shown smaller differences than MA in the pH change. Addition of preservative extended the storage time.

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고농도 탄산가스 충전에 의한 식품 해충 방제: 거짓쌀도둑거저리와 화랑곡나방의 살충효과에 미치는 노출시간과 식품포장 재질의 영향 (Control of Food Pests by $CO_{2}$ Modified Atmosphere: Effects of Packing Materials and Exposure Time on the Mortality of Tribolium castaneum and Plodia interpunctella)

  • 나자현;남영우;류문일;천용식
    • 한국응용곤충학회지
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    • 제45권3호
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    • pp.363-369
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    • 2006
  • 고농도 탄산가스 충전을 통한 식품 해충 방제에서 식품 포장재질과 노출시간이 화랑곡나방과 거짓쌀도둑거저리의 사망률에 미치는 영향을 조사하였다. 사용된 식품포장 재질은 3겹크라프트지(KKK), 2겹 크라프트-1겹 라미네이트 코팅지(KLK), 2겹크라프트-1겹 HD 코팅지였다(KHK). 탄산가스 농도가 85% 로 충전된 실험구(직경 1.2 m)에 투입 하루 후각 재질의 봉투($9.8{\times}9.8cm$) 내 탄산가스 농도는 KKK($26.67{\pm}0.58%$)에서 다른 재질 봉투에 비해 유의하게 높았다. 화랑곡나방과 거짓쌀도둑거저리의 사망률은 KKK 재질의 봉투에서 다른 재질에 비해 유의하게 높았다. 실제 식품보관 창고($9{\times}4{\times}3m$)에서 대형 포대(20 kg)를 대상으로 한 실험에서도 유사한 결과를 얻었다. 포장재질의 영향은 화랑곡나방 보다 내성이 강한 거짓쌀도둑거저리에서 두드러졌다. 화랑곡나방과 거짓쌀도둑거저리의 사충률은 누적 농도시간 (${\int}_{0}^{t}c{\times}tdc{\approx}{\sum}$농도${\times}$시간)에 회귀하였다. 이 결과를 토대로 탄산가스 충전에 의한 방제효과를 식품포장 재질, 식품의 종류, 누적농도시간과 연관하여 고찰하였다.

Fresh Produce Container Operated with a Routine of Hypobaric Application, CO2 Injection and Diffusion Tube Opening for Keeping Beneficial Modified Atmosphere

  • Park, Su Yeon;An, Duck Soon;Lee, Dong Sun
    • 한국포장학회지
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    • 제26권2호
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    • pp.53-60
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    • 2020
  • A concept of household container to create and keep the modified atmosphere (MA) beneficial for fresh produce mix was devised and tested under typical chilled storage conditions of 3℃. The container system containing mixed products is initialized by applying weak hypobaric condition (0.9 atm) and subsequently injecting CO2 gas at an appropriate low level (0.03 atm). The passive atmosphere modification by produce respiration is then induced to reach a target until gas diffusion tube of proper dimension starts to open. The design was made to attain quasi-steady state mass balance of O2, CO2 and N2 to maintain the desired MA through the storage. Interrupted opening for taking out or placing some products was to reinitialize the loop of control logic. The developed concept was tested by the container which held commodities of spinach, pak choi, oyster mushroom, peeled onion, strawberry and cut carrot. The target optimum MA of 11% O2 and 10% CO2 (0.11 and 0.10 atm, respectively) was set to avoid injurious range of O2 and CO2 concentrations for any commodities. The developed container system could work to reach and maintain beneficial MA of 0.10-0.12 atm O2 and 0.07-0.10 atm CO2 close to the target during the storage contributing to quality retention of products measured in weight loss, chlorophyll content of spinach, ascorbic acid content of pak choi, color of onion, texture of oyster mushroom, bacterial count of strawberry and carotenoids of carrot. The container system shows potential to improve current preservation practice of fresh produce mix on consumers' level.

Developments and applications of a modified wall function for boundary layer flow simulations

  • Zhang, Jian;Yang, Qingshan;Li, Q.S.
    • Wind and Structures
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    • 제17권4호
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    • pp.361-377
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    • 2013
  • Wall functions have been widely used in computational fluid dynamics (CFD) simulations and can save significant computational costs compared to other near-wall flow treatment strategies. However, most of the existing wall functions were based on the asymptotic characteristics of near-wall flow quantities, which are inapplicable in complex and non-equilibrium flows. A modified wall function is thus derived in this study based on flow over a plate at zero-pressure gradient, instead of on the basis of asymptotic formulations. Turbulent kinetic energy generation ($G_P$), dissipation rate (${\varepsilon}$) and shear stress (${\tau}_{\omega}$) are composed together as the near-wall expressions. Performances of the modified wall function combined with the nonlinear realizable k-${\varepsilon}$ turbulence model are investigated in homogeneous equilibrium atmosphere boundary layer (ABL) and flow around a 6 m cube. The computational results and associated comparisons to available full-scale measurements show a clear improvement over the standard wall function, especially in reproducing the boundary layer flow. It is demonstrated through the two case studies that the modified wall function is indeed adaptive and can yield accurate prediction results, in spite of its simplicity.

소비자의 의류쇼핑동기유형과 점포에 관한 연구 -선호점포와 점포분위기- (A Study on Clothing Shopping Motivations and store - Preferred Stores and Store Atmosphere -)

  • 박수경;임숙자
    • 한국의류학회지
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    • 제20권3호
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    • pp.414-428
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    • 1996
  • This study intends to ascertain the importance of store atmosphere when construcing store marketing strategies for store differentiation. And it is studied by classifying consumer groups according to clothing shopping motivations, comparing store atmosphere assessment and emotion response of preferred stores, and analyzing the influence store atmosphere has on store preference or impulsive purchase. The subject of this study are women in their twenties living in Seoul, 255 career women and 233 college students totaling 458, and model sampling is done by convenient sampling taking into account the type of their occupation and major. Modified survey based on references and former studies is used, and using SAS packages, methods. The results of data analysis are as follows. 1. Consumer groups are classified into the following four subdivisions: shopping involvement, leisure pursuit, financial, and shopping unconcern group. The stores women in twenties use most frequently for shopping are department stores, speciality stores, common market, discount stores, and wholesale markets, and significant difference are shown between consumer groups. 2. Consumer responses for store atmosphere preferences are shown significantly among groups when concerned with store preferences. 3. Images of store atmosphere as factor analyzed into environment factor, kindness factor, and decoration factor, Environment factor is most highly estimated in speciality stores, kindness factor in department stores, and decoration factor in common markets. 4. Leisure pursuit group is assessed to be most influenced by store atmosphere in store seleciton, impulsive purchase, and after-purchase shopping behavior, and impulsive purchase is shown highly in department stores and speciality stores.

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CA 및 MA 저장이 수삼 및 홍삼의 외관품질 및 사포인 조성에 미치는 영향 (Effect of Controlled Atmosphere and Modified Atmosphere Storage on the Apparent Quality and Saponin Component of Fresh and Red Ginseng)

  • 전병선;성현순
    • Journal of Ginseng Research
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    • 제19권1호
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    • pp.62-72
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    • 1995
  • During the controlled atmosphere storage (CA), fresh ginseng showed good appearance in quality, and other deterioration of freshness was not observed until 12 weeks. On the other hand, MA storage had kept freshness only in treatment of 1 until 8 weeks. There was no significant difference between treated and non-treated sample with preservatives, and not treated sample was not infected with various different fungi. Moisture contents and hardness of ginseng in all treatments were not changed much until 12 weeks, and surface shrinkage did not occur either. But shear stress increased somewhat in all treatments after 12 weeks. The granule of microstructure in tissue diminished slightly. The apparent Quality of red ginseng was good until 4 weeks of treatment. But as time passed, white skin and wrinkled skin were generated and darkened in its color. B-1 in CA and E-1 in MA were found to be the most favorable one. The content of crude saponin did not change significantly during storage of CA or MA by preservation conditions and period. Though a small increase in saponin content from 4.92% to 5.43% was recognized in B-1, which was treated with preservative and 6.0% In B-2, control, this could rather explain increment of soluble component by butanol. Thus, there was no change in total contents of ginsenoside pattern and composition of each content. The Rbl content in B-1 and B-2 were 0.98%, and 0.97%, respectively, whereas that of control was 0.96%. E-1 of MA, treated with preservative was 5.32% after 12 weeks, but was 5.73% in control, indicating that ginsenosides pattern was quite similar to that of CA storage.

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‘쓰가루’사과의 유통용 신선도유지 MA 포장 효과 (Modified Atmosphere Packaging of ‘Tsugaru’Apple(Malus domestica Borkh) for Distribution)

  • 박종대;홍석인;박형우;김동만
    • 한국식품저장유통학회지
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    • 제6권4호
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    • pp.357-364
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    • 1999
  • 수확후 품질이 급속히 저하되어 저장력이 약한 단점 때문에 유통기간이 매우 짧은 '쓰가루' 사과를 대상으로 플라스틱 필름과 에틸렌 흡착제 첨가에 따른 MAP(modified atmosphere packaging)의 품질유지 효과를 비교하였다. 필름 포장내의 $O_2$$CO_2$ 함량은 포장 후 4~6일 후 까지 급격히 변화하였고, 에틸렌 농도도 밀봉 직후 급격히 증가하여 저장 4일 후 40 $\mu\textrm{m}$ 두께의 LDPE 필름 포장구(40LD)에서 2,045 ppm까지 증가한 후 감소하였다. 저장중 품질변화 측정에서 대조구의 중량손실은 저장 60일 후 3.0% 이상이었으나 포장구는 저장 60일 후에도 0.6% 이하의 수준이었다. 저장중 적정산도 및 가용성고형분 함량 변화는 처리구간 유의적인 차이가 없었으나, pH는 대조구와 포장구간에 차이가 있었다 '쓰가루'의 저장중 경도는 저장초기 18일까지 급속히 감소하였으며, 40LD와 40$\mu\textrm{m}$ 두께의 에틸렌 흡착제 첨가 포장구(40LP)는 저장 60일 후 경도가 높게 유지되었다. 저장중 과피색 변화는 색소 분해로 인한 퇴색이 빠르게 진행되었으며, 저장 30일 이후부터 40LP가 저장중 변색이 가장 억제되었다. 외관품질은 저장 30일 후부터 대조구와 포장구가 차이가 났다. 관능검사에서도 대조구에 비해 포장구가 외관과 종합적기호도에서 유의적으로 우수함을 보였다. 이와 같은 결과를 종합해 볼 때 조생종 사과인 '쓰가루'의 유통중 신선도 유지를 위한 포장재료로 40 $\mu\textrm{m}$ 두께의 LDPE 필름의 사용가능성이 있으며 에틸렌 흡착제를 필름안에 같이 처리하면 더욱 효과가 있을 것으로 판단되었다.

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