• 한국식품과학회지
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• 제43권4호
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• pp.509-512
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• 2011

동결건조 쌀죽의 품질특성에 미치는 동결속도의 영향을 조사하기 위하여 쌀죽을 -20, -40, -70$^{\circ}C$의 동결 온도에서 동결시킨 후 동결건조시킨 제품을 제조하여 이들 제품의 미세구조, 물리적 강도, 조직감 및 재수화율을 조사하였다. 전자주사현미경을 통한 이들 제품의 미세구조를 관찰한 결과 완만동결(-20$^{\circ}C$)시킨 것이 급속동결(-70$^{\circ}C$)에 비해 공극의 크기가 크고 그 수가 적었다. 반면에 급속동결시킨 제품은 보다 조직이 치밀하고 물리적인 강도가 유의적(p<0.05)으로 큰 값을 나타냈다. 수화복원율은 -20$^{\circ}C$에서 동결시킨 제품이 -40, -70$^{\circ}C$에서 동결시킨 제품보다 높았다. 따라서 품질이 우수하고 사용이 간편한 동결건조 쌀죽을 제조하기 위해서는 최적의 동결 온도의 선택이 필수적임을 알 수 있었다.

• 생명과학회지
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• 제27권4호
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• pp.471-475
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• 2017

마늘의 동결 전처리는 세포막을 파괴할 수 있으며, 식품 품질을 향상시킬 수 있다. 따라서 전통적인 흑마늘 가공방법과 $-20^{\circ}C$와 $-70^{\circ}C$에서 동결 전처리후 숙성 흑마늘의 효과를 비교하였다. 실험 결과, $-70^{\circ}C$에서의 동결 전처리가 흑마늘의 품질과 항산화 활성에 가장 큰 영향을 미치는 것을 확인하였다. 동결 전처리와 숙성과정을 거친 흑마늘의 갈변화 정도와 pH는 각각 3.14와 3.55로 나타났고, DPPH free radical 소거 활성 및 환원력은 동결 전처리 과정을 통해 향상시킬 수 있었다. 또한 동결 전처리 후 흑마늘의 환원당 및 5-hydroxymethyl-2-furaldehyde (5-HMF) 함량은 대조군 흑마늘에 비해 각각 1.69 및 1.14배 증가하였다. 그 결과 동결 전처리는 전반적인 품질(갈변정도, pH, 환원당)과 흑마늘의 기능성을 향상시킴을 확인할 수 있었다.

• Journal of Applied Biological Chemistry
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• 제58권1호
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• pp.55-60
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• 2015

수출용 냉동딸기 제조 시 미생물학적 안전성 확보를 위한 수단으로 이산화염소수와 acetic acid 병합처리를 최적 비가열 전처리 기술로써 적용하여 -20, -70, $-196^{\circ}C$로 냉동한 후 미생물 수, 품질변화 및 관능평가를 조사하였다. 냉동방법 및 세척 처리에 따른 색도 차이는 나타나지 않았고, 비타민 C 함량은 $-70^{\circ}C$ 냉동에서 35.33 mg/100 g FW로 가장 대조구와 유사하였으며, drip loss도 $-70^{\circ}C$ 냉동이 14.39%로 가장 낮게 나타났다. 관능평가 역시 $-70^{\circ}C$ 냉동이 -20, $-196^{\circ}C$ 냉동보다 높은 점수를 받았으며, 세척처리는 비타민 C 함량, drip loss 및 관능평가에 큰 영향을 끼치지 않는 것으로 나타났다. 또한, 냉동딸기에 50 ppm 이산화염소수와 1% acetic acid를 병합 처리하여 냉동 후 미생물 수 변화를 측정한 결과, 냉동 전과 같이 병합처리 된 딸기 시료에서 미생물이 검출되지 않았다. 따라서 저장성이 높은 수출용 냉동딸기 생산을 위해서는 gas nitrogen convection chamber를 이용한 $-70^{\circ}C$에서의 급속냉동 처리가 보다 효과적인 냉동방법이며, 냉동 처리만으로는 미생물 제어가 어렵기 때문에 냉동 전 비가열 전처리를 통해서 냉동딸기의 미생물학적 안전성을 확보해야 한다고 판단된다.

• 동아시아식생활학회지
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• 제14권5호
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• pp.443-448
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• 2004

In order to investigate the optimal factors for frozen dough production, the freezing and thawing condition such as temperature and time, storage period and the effect of ingredient addition were determined. A pre-fermentation of dough at 30℃ for 120 minutes was appeared to be the best for the production of frozen dough. The dough was frozen at -18℃ and then stored for 7 days. The quality of frozen dough was found to be optimal when thawed at 30℃ for 80 minutes. As ingredient of frozen dough, an addition of 3% of yeast and 4% of butter was good as well as the addition of skim milk and sugar in terms of fermentation capacity after thawing.

• Journal of the Korean Wood Science and Technology
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• 제25권3호
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• pp.66-74
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• 1997

Liquid permeabilities of red oak and several softwoods were measured by the pressure bomb method and a modified liquid permeability method in order to investigate their efficacy. The effect of preboiling and prefreezing on wood permeability were also examined for both green and resaturated specimens. Regardless of some disadvantages these two methods were revealed as a handy tool for quick evaluation of the permeability of an unknown species. The permeabilities of the resaturated specimens increased when preboiled. but decreased when prefrozen. For green specimens, however, pre freezing increased permeability. The discrepancy of the pre freezing effect on two specimens partially attributes to their difference of initial permeabilities. For all species except radiata pine heartwood, the radii of the effective capillary pores, derived from the water potential equation, distribute from $0.42{\mu}m$ to $7.2{\mu}m$. Those of radiata pine heartwood are below $0.46{\mu}m$.

• Journal of Applied Biological Chemistry
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• 제57권2호
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• pp.161-164
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• 2014

수확 후 블루베리, 복분자, 오디의 냉동 전처리 조건 및 미생물학적 안전성 확립을 위한 최적 세척조건을 연구하였다. 사용된 세척처리 중에서 50 ppm 이산화염소수와 0.1% 푸마르산의 병합처리가 대조구와 비교 시, 블루베리, 복분자, 오디의 총 호기성 세균에 있어서 2.56, 2.26, 2.56 log CFU/g을 감균시켜서 가장 효과가 높았다. 또한 병합처리는 효모 및 곰팡이 수에서도 2.24, 2.08, 1.49 log CFU/g 감소시켰다. 따라서 본 연구결과 블루베리, 복분자, 오디의 냉동 전처리 조건으로써 50 ppm 이산화염소수와 0.1% 푸마르산 세척 병합 처리가 냉동 베리류의 미생물학적 안전성 확보를 위한 가장 좋은 전처리 방법이라고 판단된다.

• Reproductive and Developmental Biology
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• 제34권3호
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• pp.271-274
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• 2010

This study was conducted to investigate the survival rate of frozen-thawed spermatozoa in equine by glycerol concentration and freezing speed Two stallions (1 Thoroughbred-13 year old and 1 Arab-7 year old) bred in Korea Racing authority was examined for 1 times in a couple of weeks. Semen was collected by condom method standing heated mare and were centrifuged 650 g for 15 min. and isolated the seminal plasma. Thick fraction of semen was diluted EDTA-Lactose-egg yolk diluents to 1:1 and contained in 0.5 ml straw as $6{\sim}14{\times}10^7\;cells/ml$. Final concentrations of glycerol were 3, 5 and 7% in cryopreseved diluents and added 4 times for 2 hours equilibration. For the freezing, equilibrated straws were located 3 or 5 em above $LN_2$ gas for 5 or 10 min. Survival rates of pre-frozen sperm were $65.0{\pm}13.2%$, $68.3{\pm}10.4%$, $66.7{\pm}11.5%$ and post-frozen were $53.3{\pm}23.1%$, $45.0{\pm}15.0%$, $50.0{\pm}18.0%$ in 3, 5, 7% glycerol concentration, respectively. There was no difference between glycerol concentrations. Survival rates of frozen-thawed sperm on freezing speed were $36.7{\pm}10.4%$, $40.0{\pm}7.1%$, $30.0{\pm}13.2%$ at 3 cm-5 min and $33.3{\pm}11.5%$, $31.7{\pm}2.9%$, $21.7{\pm}10.4%$ at 3 cm-10 min in 3, 5, 7% glycerol concentration, respectively. Survival rates of frozen-thawed sperm on freezing speed were $43.3{\pm}15.3%$, $32.0{\pm}17.9%$, $22.3{\pm}15.7%$ at 5cm-5 min and were $47.5{\pm}15.0%$, $43.3{\pm}12.6%$, $48.3{\pm}15.3%$ at 5cm-10 min in 3, 5, 7% glycerol concentration, respectively. There were significantly different between groups (p<0.05). These results suggest that glycerol concentration did not affect cryopreservation of stallion semen within 3~7% but freezing speed affects. In our experiment, the best cryopreservation condition was at 5 cm above $LN_2$ gas for 10 min for pre-freezing and 7% of glycerol concentration. These results lead to commercial AI with frozen-thawed stallion semen.

• Reproductive and Developmental Biology
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• 제34권3호
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• pp.253-256
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• 2010

This study was performed to investigate the characteristics within ages and freezing tolerance of spermatozoa in Jindo Dog. Experimental animals were selected 12 herds within 1~8 year's old and collected semen for 2 times in a week. Collected semen was evaluated whole volume and sperm number with CASA system (SIAS, Medical Supply, Korea). Then seminal plasma were separated and diluted with modified Tris-egg yolk extender and added 4, 6 and 8% glycerol for 4 times to final concentration and equilibrated for 1.5 hrs. Before and after freezing, equilibrated semen were evaluated the survival rates. Total volume of sperm at 1~2 year old group is as $5.2{\times}10^8\;cells/ml$ largest and there were no significance among groups. The motility of 1~2 year old group is highest as 90.9% and there were significance among groups. Abnormal sperm showed similar among groups. The survival rate in terms of pre-freezing and post-freezing were decreased all levels of glycerol and reveled 87.0% to 64.5% in 4%, 87.5% to 51.9% in 6% and 73.4% to 29.7% in 8%, there were significant difference among the groups (p<0.05). These results suggest that the optimal sperm-freezing methods in Jindo Dog are utilized with modified Tris egg-yolk extender with 4% glycerol and were improve the reproductive activity by these methods.

• 한국식품과학회지
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• 제35권4호
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• pp.660-665
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• 2003

은하콩과 태광콩의 수화속도 및 콩나물 생육 특성에 대한 동결처리의 효과를 수화반응에 대한 속도론적 연구와 콩나물의 재배실험을 통하여 조사하였다. 수화시간에 대한 동결처리의 영향은 침지온도에 따라 달랐는데, $60^{\circ}C$ 이하의 침지온도에서는 수화시간이 15-50% 정도 감소하였으며, $60^{\circ}C$ 이상의 침지온도에서는 수화시간이 감소하지 않았다. 동결 처리한 은하콩과 태광콩의 수화반응에 대한 활성화 에너지는 각각 39.79 및 39.25 kJ/mol로서 동결처리를 하지 않은 콩에 비해 약 20%정도 감소하였다. 은하콩과 태광콩은 동결처리에 의해 콩나물의 발아율, 길이 및 무게는 증가하였으며, 콩나물의 수율은 약간 감소하였고, 굵기는 콩의 품종에 따라 달랐다.

• 한국가축번식학회지
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• 제16권1호
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• pp.47-53
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• 1992

This study was carried out to investage the effect of cryoprotectant concentration and equilibration time on volume change and in vitro development of intact and bisected mouse embryos by rapid freezing. When compacted morulae were rapidly frozen in 3.0 to 4.0 glycerol or DMSO with 0.25M sucrose solution, the superior(P<0.05) post-thaw survival rate was obtained at the glycerol concentration of 4.0M(89.4%) than 3.0M(71.4%) or 5.0M(42.4%), but at the DMSO concentration of 3.0M(84.5%) than 4.0M(51.1%) or 5.0M(0.0%). The optimal equilibraton time for rapid freezing of ZP-free or bisected morulae in 4.0M glycerol with 0.25M sucrose was found tobe 3 minutes. The minimal volume of compacted morulaewhich corresponded with 61 to 62% of pre-equilibrated embryo volume was obtained from equilibration for 3 minutes in both 3.0 and 4.0M glycerol solutions with 0.25M sucrose.