• Journal of Bio-Environment Control
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• v.1 no.2
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• pp.169-174
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• 1992

This experiment was carried out to investigate the possibility of practical use of intermittent soaking system(ISS) in hydroponicaly growing tomato. There were four treatments which were NFT, Aeroponics, and ISS with 10 and 15 minute soaking intervals. 1. Plant height is highest in NFT, but main root length is longest in ISS. While stem diameter and leaf number were not significantly difference. 2. Fresh and dry weight were heavier in NFT than those of other systems at early growth stage, but the heavier in ISS system, the growth more develop. 3. In 43 days after treatment, the number of flowerlet was largest in aeroponics, and then ISS and NFT in order. Fruit weight per plant was also heaviest in aeroponics. 4. Average yield per plant were 1929.1g in aeroponics, 1475.2g in ISS with 10 minute soaking interval, 1276.2g in NFT and 1084.8g in ISS with 15 minute soaking interval. 5. Average fruit number per plant were 11.0 in aeroponics, 9.7 in NFT, 8.3 in ISS with 15 minute soaking interval, and 7.7 in ISS with 10 minute soaking interval. Average fruit weight were 192.9g in aeroponics, 172.4g in ISS with 10 minute soaking interval, 134.0g in NFT and 126.0g in ISS with 15 minute soaking interval. 6. Average fruit length was longer in aeroponics and ISS with 10 minute soaking interval than in the NFT and ISS with 15 minute soaking interval. Average fruit width was similarly wider in NFT, aeroponics and ISS with 10 minute soaking interval than in ISS with 15 minute soaking interval.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.413-418
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• 2002

The dough was frozen either before or after fermentation at the five different freezing and storage conditions. Although fermentation before freezing was effective for rapid freezing, it reduced bread volume of the dough frozen at both air freezer and liquid immersion freezer. Freezing at the air freezer set to $-70^{\circ}C$ took more time for freezing and resulted in lower bread volume than freezing at the immersion freezer set to $-20^{\circ}C$. Therefore, the freezing in the liquid immersion freezer was more effective to reduce the freezing time and increase the bread volume. At the liquid immersion freezer, the higher temperature was more effective than lower temperature. The doughs frozen in a liquid immersion freezer set to $-10^{\circ}C$ and fermented after de-frosting produced higher bread volume than control unfrozen dough. And also there was no significant difference in bread volume between the control unfrozen dough and the dough frozen in a liquid immersion freezer set to $-10^{\circ}C$, fermented before freezing and re-fermented after defrosting. The longer proof time and greater loaf volume obtained for the dough frozen and stored at the air freezer set to $-70^{\circ}C$. Therefore the optimum process for freezing the dough was freezing immediately after mixing, storing at $-10^{\circ}C$ in a liquid immersion freezer and fermented after defrosting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.230-238
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• 2016

This study examined the effects of freezing and thawing conditions on quality of Hanwoo bottom round. The beef samples were frozen by air blast freezing at $-20^{\circ}C$ or ethanol immersion freezing at $-70^{\circ}C$ and then stored at $-20^{\circ}C$ for 10 days. After 10 days of storage, the frozen samples were thawed with air blast thawing at $4^{\circ}C$ or water immersion thawing at $4^{\circ}C$ and subjected to subsequent analyses of drip loss, water holding capacity, thiobarbituric acid reactive substance (TBARS), volatile basic nitrogen (VBN), total aerobic bacteria, and microstructure. Drip loss significantly increased in samples treated with air blast freezing compared to ethanol immersion freezing, whereas freezing and thawing processes had no significant impact on water holding capacity of the samples. Thawing conditions had a much stronger influence on the TBARS and VBN of the samples than freezing conditions. There was no significant difference in the population of total aerobic bacteria among the four samples subjected to one freeze-thaw cycle. In addition, to analyze the effects of freeze-thaw cycle on the quality of beef, three freeze-thaw cycles were performed during storage. Multiple freeze-thaw cycles increased drip loss, TBARS, and VBN and decreased water holding capacity, accelerating microstructural damage. These data indicate that Hanwoo bottom round can be rapidly frozen and thawed by using ethanol immersion freezing and water immersion thawing methods with minimal impact on meat quality.

• 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.179.2-180
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• 2003

본 연구에서는 과채류의 냉동냉장시 내부압력에 따른 조직파괴를 방지하기 위한 기초연구로 동결방법에 따른 내부압력 변화에 대하여 조사하였다. 과채류의 동결에 의한 중량감소율은 침지식 동결방식에서 0.44∼l.38% 수준으로 가장 적게 나타났으며, 동결방식에 따른 중량감소율 차이는 수박에서 가장 심하여 수분함량에 클수록 동결속도에 따른 효과가 비교적 크다는 것을 알 수 있었다. 동결속도에 따른 내부압력은 배, 사과 및 메론에 있어 침지식 방법에 의한 동결시 체적팽창 및 수축에 따른 내부압력 차가 가장 적게 나타났으며, 송풍식 동결에서 가장 크게 나타나 동결속도가 빠를수록 내압의 크기는 적다는 것을 알 수 있었으나 딸기 및 수박의 경우는 오히려 침지식에서 내압이 가장 크게 나타났다. 균온 처리하지 않은 동결에 있어 과일의 내부압력 변화는 약 2 psig수준인 반면에 균온 처리한 수박의 내부압력 변화는 균온 처리하지 않은 수박의 내부압력 변화 경향과 유사하지만 일정한 수준의 내압을 발생시킴으로써 내부압력의 크기도 약 1.3 psig수준으로 상당히 적게 나타났다. 또한, 해동시에 있어서도 균온처리한 시료의 내부압력 크기가 균온처리하지 않은 내부압력 크기보다 상대적으로 적게 나타났다. 균온처리 동결시, 다단계 처리보다는 3∼4회 수준의 일정한 균온 처리가 내부압력의 증감 폭을 줄일 수 있었다.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.83-89
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• 1995

Changes in physical, chemical and microbiological characteristics of rice-doenjang prepared with two different methods with or without soak treatment were investigated during 60 days of aging at $32^{\circ}C$ and $15^{\circ}C$. The pH of soak-treated rice-doenjang decreased slowly, but that of nonsoak-treated rice-doenjang decreased rapidly at the initial aging stage with the aging temperature of $32^{\circ}C$, resulting in pH 5.1 after the 60 days of aging time. Reducing sugar contents increased up to the $30{\sim}50$ days of aging time and decreased thereafter. The contents of soluble nitrogen, formol nitrogen, ammoniacal nitrogen and amino nitrogen were more affected by preparation methods than by aging temperatures. Color values depended not only on preparation methods but also on aging temperatures. There were no significant differences in the bacterial counts of rice-doenjang, while apparent differences in the yeast and mold counts by aging temperatures were observed. These results suggested that the properties of soak-treated rice-doenjang were less changed than those of nonsoak-treated rice-doenjang by aging time and temperature. And, with a view point of nitrogen compounds, aging time could be reduced by soak treatment.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.416-423
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• 2007

This study investigated the effect of ohmic thawing on the physicochemical properties of pork meat. The physicochemical properties of pork meat thawed by brine immersion and electrode contact ohmic systems were compared. A more rapid thawing rate was seen with the electrode contact thawing system than with brine immersion. No significant differences in pH were found with increasing voltage for both thawing methods (p>0.05). Increasing the voltage level tended to decrease drip loss, resulting in increased water holding capacity. The shear forces of pork thawed at 50 V did not differ from the control (p>0.05) for both thawing methods. Although significantly high TBARS (p<0.05) values were found at 20 and 40 V for immersion, and 0 V for contact thawing, increasing the voltage level tended to decrease the TBARS values. Regarding TVBN, no significant effect was observed with increasing voltage levels (p>0.05). The total color difference of pork was significantly higher (p<0.05) with immersion thawing than with electrode contact thawing. These results indicate that brine immersion thawing is favorable at high voltage levels, while lower voltage levels are applicable for electrode contact thawing.

• Proceedings of the Membrane Society of Korea Conference
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• 2005.07a
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• pp.73-104
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• 2005

• Journal of Korean Society of Water and Wastewater
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• v.22 no.1
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• pp.79-86
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• 2008

In Korea, most of the drinking water treatment relied upon the availability of the surface water, of which the raw water quality varied significantly by season and location. Therefore, the comparison of two operation modes (Pressurized type and Submerged type membrane system) must be estimated before the long-term establishment of two systems. In this study, two pilot-scale microfiltration systems with the capacity of $50m^3/day$ were installed and operated in two different modes, and the applicability of the system was determined based on the results such as the TMP (Trans-Membrane Pressure) and flux. For quantitatively comparing the two systems, a new concept, DRF (Differential Resistance Fraction) was introduced. The accumulated sum of the permeate after each cycle of chemical cleaning was also used as a tool for the system comparison.

• Proceedings of the Membrane Society of Korea Conference
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• 2003.11a
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• pp.143-145
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• 2003

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1997.06a
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• pp.348-349
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• 1997