• 한국식품조리과학회지
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• 제31권1호
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• pp.62-71
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• 2015

The purpose of this study was to evaluate the changes on the characteristics of the oxidative stability of Tenebrio molitor larvae during cold storage at $4^{\circ}C$. Pretreatment for T. molitor larvae was designed into three methods: raw (R), freeze-dried (F.D.), and pan-fried (P.F.). The water content of the raw sample (61.46%) was higher than those of other samples (F.D.: 5.02%, P.F.: 3.67%) and its high water content was expected to facilitate the oxidation of the raw sample. In our results, the peroxide value and the carbonyl value of all of the samples increased and the raw sample, after storage for 18 day, showed the highest value. The pan-fried sample had no significant increase in its lactic acid content, acid value, and thiobarbituric acid value; whereas those values were increased in the raw sample and the freeze-dried sample (p<0.05). The browning reaction was more progressed in the pan-fried sample than other samples at 0 day, but there was no significant change during the storage. The raw sample and the freeze-dried sample had their browning indexes increase with the increasing storage period (p<0.05). The pan-fried sample produced less oxidation products than the freeze-dried sample, indicating that the unheated sample was more susceptible to oxidation than the heated samples. In conclusion, heating treatment and low water content would be effective for improving the safety and stability of T. molitor larvae during cold storage.

• 한국식품과학회지
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• 제35권2호
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• pp.254-259
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• 2003

본 연구에서는 동결건조된 열무김치를 0, 10, $25^{\circ}C$에 60일간 저장하면서 동결건조/저장/복원시료의 젖산균수, pH, 관능적특성을 관찰하여 다음과 같은 결과를 얻었다. 동결건조된 열무김치의 적정한 복원시간은 2시간이었다. 동결건조/저장/복원시료의 저장중 젖산균수는 저장 10일만에 표준시료와 비교하여 유의적으로 감소하였으며(p<0.05), 그 이후에는 큰 변화가 없었다. 한편 저장온도가 높을 수록 10일시료의 젖산균수 감소 정도가 높았다. pH는 동결건조에 의하여 다소 증가하였으나, 60일 저장기간 중에 점차 저하하는 경향을 보였다. 동결건조/복원 열무김치의 관능적특성은 표준시료(동결건조전 시료)와 비교하면 기호성이 다소 낮았으나, 동결건조/복원시료만 단독으로 시식하면 기호성이 비교적 양호하였다. 동결건조/저장/복원시료의 전반적인기호도는 $0^{\circ}C$저장시료의 경우 표준시료보다 유의적으로 낮았으며(p<0.05), 저장온도가 증가할수록 전반적인기호도도 점차로 저하하였다. 저장기간이 10일에서 60일로 연장됨에 따라 $0^{\circ}C$나 $10^{\circ}C$저장시료의 관능적 특성은 다소 저하하였으나 $25^{\circ}C$저장시료의 관능적특성은 현저하게 저하하였다.

• Journal of Microbiology
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• 제43권2호
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• pp.196-203
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• 2005

Here, we attempted to evaluate the activity of artificially transconjugated multiple plasmids in 'designer biocatalysts' for the bioremediation of cocontaminated sites under nonselective conditions. We observed profound losses in the percent survivals of artificially transconjugated plasmid activity ($66 - 78\%$ loss immediately after freeze-drying, $99.45 - 99.88\%$ loss by the end of 6 months storage) in reconstituted Pseudomonas sp. KM12TC. Such unpredictable high losses of this particular plasmid appeared to clearly be a deleterious effect. However, even after 6 months of storage, the cells remained able to degrade $95\%$ of phenol within 9 days, and the full effiux of$^%${73} As, as compared to that of the non-freeze-dried cells, was successfully achieved 4 to 9 days later. These results indicate that 'stable designer biocatalysts' can remain viable, even after freeze-drying and 6 months of storage.

• Journal of Ginseng Research
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• 제18권1호
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• pp.60-65
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• 1994

Fresh ginseng of same grade was stored under the 4$\pm$1$^{\circ}C$ and 87~92% RH for 10 weeks. During the storage, an aliquot amount of the ginseng was drawn, freeze dried and chemical constituents and physicochemical parameters were measured. After 10 weeks of storage drying rate and shrinkage of ginseng were 1520% and 9.04%, respectively, mold growth was seen at week 5 and observed for 51.2% of the ginseng week 10. Amylase activity level was elevated at the early stage of storage and decreased to 5% of initial value at week 5. At week 5, the elevated amylase activity was inconcomitant with the appearance of the mold growth. Crude protein contents were increased and decreased, respectively 5 week post storage. No significant changes in crude fat, crude fiber, ash, total sugar, n-butanol extract and ginsenoside were observed. The content of water-extractable substance showed maximum at week 7 to 8. The value of pH was slightly elevated and reducing sugar was increased during the storage. Key words Ginseng storage, physicochemical properties, drying rate, shrinkage, amylase activity.

• 한국식품영양학회지
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• 제23권1호
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• pp.23-29
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• 2010

Pigment concentrates with violet-red color and sweet taste were obtained from purple-fleshed sweet potato(PFSP) using ethyl alcohol and water. Extract from general potato(GP) were used as a control. The relative stability of PFSP pigment concentrate(PFSPPC) in a storage test over 15 days was confirmed in the order of dark > fluorescence > sun-light irradiation. The relative stability of GP pigment concentrate(GPPC) in a storage test over 15 days was confirmed in the order of sun-light > fluorescence > dark storage. The RRP of PFSPPC was higher than that of GPPC, but the color strength of GPPC was 1/2 that of PFSPPC. Treatment of PFSPPC with aluminum potassium sulfate(0.2~0.3%, w/w) best improved its stability. The improved RRPs of PFSPPC were 45.16~47.31% in sun light irradiation, 55.91~60.22% in fluorescence irradiation, and 76.34~75.97% in dark storage conditions. In substituting aluminum potassium sulfate for chitosan, an amount of 0.2~0.3%(w/w) was suitable, giving similar results in improving pigment stability for all concentrates tested. Also, freeze-dried PFSPPC powder was manufactured as a substitute for dextrin, and also as a substitute for chitosan to the extent of 0.25%(w/w). The results of storage stabilite for freeze-dried PFSPPC and GPPC powder over 15 days, irradiation were, PRRs of 74.47~89.36% and 61.54~76.92%, respectively. The stability improving effect of freeze dried PFSPPC powder was confirmed by the results of storage experiments at various conditions. The use of freeze-dried PFSPPC powder was therefore confirmed to be an effective treatment for general foods.

• 설비공학논문집
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• 제20권9호
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• pp.631-636
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• 2008

Solar thermal systems are recently refocused by higher oil prices, but did not completely restore the people's confidence owing to the past bad systems. Several types of solar water heating systems were analyzed in characteristics and some proper systems were proposed under Korean climates and system scale. As a small system, natural circulation system should be installed only in a southern region of Korea, with a freeze protection valve instead of heating coil for freeze protection. In most area of Korea, the forced circulation type with a heat exchange coil inside a thermal storage tank or with a spiral-jacketed storage tank, proposed and verified by the authors, has a merit of stable performance and freeze protection.

• 한국식품영양학회지
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• 제34권3호
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• pp.263-271
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• 2021

Fresh Omija (Schisandra chinensis) has good marketability, but its quality is difficult to maintain during storage and distribution. Freezing and freeze-thawing treatments can be utilized for the quality maintenance and processing of cold press juice. In this study, the color, antioxidant properties, and the major components of soaked liquor from Omija with freeze-thawing treatment were analyzed during the extraction periods. Each of the frozen and freeze-thawed Omija samples was soaked in 35% ethanol, extracted for 15 days, and used for analysis. The frozen and freeze-thawed samples showed a tendency toward better color and higher antioxidant activity and major component levels than the controls, and freeze-thawing was the best. The results of this study showed that freeze-thawing treatment improved the color, antioxidant properties, and level of the major components of Omija soaked liquor, and freeze storage is suitable for making soaked liquor.

• Preventive Nutrition and Food Science
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• 제1권2호
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• pp.252-255
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• 1996

As an index of freeze-injury of yeast, the leakage of intracellular substances from yeast cells after freeze-thawing was investigated. It was found that much more ultraviolet-absorbing substances leaked out from non-freeze tolerant yeast (NETY) than from freeze-tolerant yeast. Furthermore, the rate of leakage of cellular substances form NFTY during incubation exceeded that of FTY, indicating that NFTY is more susceptible to freeze-injury than FTY during frozen-storage. An apparent degradation of phospholipid was observed during incubation of perfermented frozen-cells of NFTY, while little change of phospholipid occurred in FTY, These results suggested that the difference in the sensitivity of yeast might be due to the strength of cell membrane in terms of the degradation of phospholipid by enzymes, phospholipases, attached to cell membranes.

• Journal of Ginseng Research
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• 제27권2호
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• pp.72-77
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• 2003

10월 초에 채굴한 6년근 수삼을 4$^{\circ}C$$\pm$1$^{\circ}C$, RH 87∼92%에 10주간 저장하면서 1주 간격으로 시료 채취하여 동결건조 인삼과 홍삼을 제조하여 성분변화를 비교조사 하였다. 총당은 저장기간의 경과에 따라 홍삼은 약간 감소하였고, 환원당은 증가하여 저장전 1.48%에서 10주째는 23.33%였다. 유리당은 홍삼에서 fructose는 증가하였으나 glucose와 sucrose 는 증가후 감소하였고 maltose는 6.62%에서 점차 감소하였으며, 동결건조인삼은 fructose, glucose, sucrose 모두 증가하여 특히 sucrose는 저장전 10.96%에서 7주째는 24.38%로 증가하였고 maltose는 검출되지 않았다. 물추출물의 수율은 7 $.$ 8주째가 약간 높았고, pH는 3 $.$ 4주째가 약간 높았으며. 탁도는 동결건조인삼은 변화가 없으나 홍삼은 감소하였다. 비수용성 단백질은 홍삼에서 검출되지 않았으며 동결건조인삼은 저장기간의 경과에 따라 비수용성단백질은 감소하고 수용성단백질은 증가하는 경향을 보였다. 페놀화합물은 홍삼과 동결건조인삼에서 각각 저장 7주와 9째 가장 높았으나 그 양은 홍삼이 높았다. 비휘발성유기산은 동결건조인삼과 홍삼 모두 citric acid는 감소하였고, glutamic acid와 pyruvic acid는 동결건조인삼에서 미량이었으나 홍삼은 최고 37 $\mu$g/g과 592 $\mu$g/g이 검출되었다.

• 설비공학논문집
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• 제23권6호
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• pp.406-412
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• 2011

This paper describes the analysis on freeze and refrigeration capacity of cold storage facilities for fisheries products during the last 15 years. And based on the analysis results, we prospect the number and scale of cold storage facilities in the near future. The main analysis results are summarized by the followings; Under the present conditions, the number and scale of our facilities is 879 and 3,586,824 ton, respectively. In comparison of the present and last 15 years ago, the business number increases about 22%, the accommodation capacity increases approximately 80%. In the reported update reference with the related data during the last 15 years, the capacity of cold storage facilities in 2011 expects to reach up to 4,600,000 ton. The newlyestablished facility in 2011 has the function of a multi-purpose distribution center as well as the existing cold storage, but this facilities converges in the capital area. Therefore, in this paper, we provided the basic reference data for the present situation and prediction of our cold storage facilities. But it is necessary to investigate and analyse widely our cold storage facilities for fisheries products in the near future.