• Food Science and Preservation
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• v.4 no.2
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• pp.189-196
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• 1997

Blanching conditions for immatured soybeans were optimized by analyzing the effects of various time/temperature blanch treatment on the activities of peroxidase and lipoxygenase, the stability of vitamin C and color, and moisture content in immatured soybeans for the purpose of minimizing quality deterioration during frozen storage. Blanching at 96$^{\circ}C$ for 70 sec led to maximum inactivation of lipoxygenase in the immatured soybeans, while my blanching conditions tested in this study were not enough to inactivate peroxidase. Blanching at 82$^{\circ}C$ for 60 sec resulted in the highest amount of vitamin C remaining in the immatured soybeans after blanching. Hunter -a/b ratios of immatured soybeans blanched at 82$^{\circ}C$ for 60 sec and hue values (ΔE) of the immatured soybeans blanched at 76$^{\circ}C$ for 60 sec showed the closest values to those of fresh products. The changes in moisture content of immatures soybeans was not so significant after blanching. In conclusion, it was suggested that immatured soybeans be blanched at 96$^{\circ}C$ for 70 sec to minimize lipoxygenase activity and resulting quality deterioration, while blanching at 82$^{\circ}C$ for 60 sec was recommended to stabilize vitamin C and color.

• Food Science of Animal Resources
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• v.37 no.4
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• pp.518-528
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• 2017

Quality characteristics of frozen cylindrical pork loin were evaluated following different tempering methods: 27.12 MHz curved-electrode radio frequency (RF) at 1000 and 1500 W, and forced-air convection (FC) or water immersion (WI) at $4^{\circ}C$ and $20^{\circ}C$. The developed RF tempering system with the newly designed curved-electrode achieved relatively uniform tempering compared to a parallel-plate RF system. FC tempering at $4^{\circ}C$ was the most time-consuming process, whereas 1500 W RF was the shortest. Pork sample drip loss, water holding capacity, color, and microbiological quality declined after WI tempering at $20^{\circ}C$. Conversely, RF tempering yielded minimal sample changes in drip loss, microstructure, color, and total aerobic bacteria counts, along with relatively uniform internal sample temperature distributions compared to those of the other tempering treatments. These results indicate that curved-electrode RF tempering could be used to provide rapid defrosting with minimal quality deterioration of cylindrical frozen meat block products.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.263-267
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• 2012

Six different types of biltong samples were manufactured from beef which was slowly frozen, quickly frozen or unfrozen. After marinating the samples according to the formulation used, meats were dried at two different temperatures ($28{\pm}1^{\circ}C$ or $42{\pm}1^{\circ}C$) until they lost half of their weights. Chemical, instrumental textural and sensorial analyses were done for determination of the most preferred sample and to compare the attributes of the samples with each other. It was found that, aw values of the samples were among 0.81 and 0.83, whereas water contents were changing among the values 39.64% and 45.37%. There were no significant differences determined among the protein contents of the biltong samples (p>0.05). Fat, ash and salt contents of the samples were among the values 1.32% and 2.07%, 5.30% and 6.06%, 2.68% and 3.30% respectively. Hardness of the samples were found between 34.81 N and 44.13 N and there was no significant difference observed among the hardness values of the biltong samples (p>0.05). As results of the analyses, it can be concluded that the highest flavor, color, tenderness and overall acceptability scores were obtained for the sample QF-LT which was made from quickly frozen beef and was dried at low temperature ($28{\pm}1^{\circ}C$) (p<0.05).

• Geomechanics and Engineering
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• v.17 no.2
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• pp.133-143
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• 2019

An optimal hydraulic section is critical for irrigated water conservancy in seasonal frozen ground due to a large proportion of water leakage, as investigated by in-situ surveys. This is highly correlated with the frost heave of underlain soils in cold season. This paper firstly derived a practical model for frost heave of clayey soils, with temperature dependent thermal indexes incorporating phase change effect. A model test carried out on clay was used to verify the rationality of the model. A novel approach for optimizing the cross-section of irrigation canals in cold regions was suggested with live updated geometry characterized by three unique geometric constraints including slope of canal, ratio of practical flow section to the optimal and lining thickness. Allowable frost heave deformation and tensile stress in canal lining are utilized as standard in computation iterating with geometry updating while the construction cost per unit length is regarded as the eventual target in optimization. A typical section along the Jinghui irrigation canal was selected to be optimized with the above requirements satisfied. Results prove that the optimized hydraulic section exhibits smaller frost heave deformation, lower tensile stress and lower construction cost.

• Applied Biological Chemistry
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• v.46 no.1
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• pp.39-45
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• 2003

This study was conducted to investigate the effect of ash contents of bread flour on the rheology of frozen dough In making frozen dough by measuring amylograph, flrinograph and extensograph. The quality of frozen-stored dough under freezing condition ($-20^{\circ}C$, 12 weeks) was evaluated by measuring final proof time, moisture content, baking loss, loaf volume and hardness of bread with storage time. In bread flour with high ash content farinogram showed that water absorption, degree of softening increased but valorimeter value decreased. In bread flour with low ash content amylogram showed that gelatinization temperature and maximum viscosity increased and extensogram showed that the area and resistance of the bread flour increased. As the proof time increased the extensibility decreased. Final proof time of frozen dough was shortened at the bread flour with low ash content with storage time. In bread using the flour with high ash content, moisture content, increased but baking loss rate decreased while the hardness of product increased slowly with time. But in bread using the flour with low ash content, the loaf volume of baking increased but the hardness of product decreased. As the frozen storage time was shortened, the product was more stable and better in quality.

• Journal of the Korean Geotechnical Society
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• v.32 no.12
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• pp.59-67
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• 2016

The strength of frozen soils is affected by size and shape of particles, and the amount of ice and unfrozen water. The objective of this study is to characterize the unfrozen water content and the unconfined compressive strength of the frozen soils according to the degree of saturations and silt fractions. The specimens are mixtures of sand, silt, and water. The silt fractions (SF), which are the ratio of the silt weight ($W_{silt}$) to the sand weight ($W_{sand}$), are 10% and 30%. In addition, the degrees of the saturation are 5%, 10%, 15%, and 20%. The specimens are frozen under the temperature of $-10^{\circ}C$ conditions. The uniaxial compression tests are conducted for 24 hours, 48 hours, and 72 hours after freezing to determine proper freezing time. The freezing time of 24 hours is chosen because the unconfined compressive strengths of specimens after 24 hours freezing times are similar to each other. Furthermore, the unfrozen water content is monitored during freezing using the TDR system. The unfrozen water content increases with the increase of the silt fraction and degree of saturation. The unconfined compressive strength of the frozen soils exponentially increases with increasing the degree of saturation. This study shows that the amount of ice has more influence on the strength of the frozen soils than the amount of unfrozen water.

• Journal of the Korean GEO-environmental Society
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• v.15 no.2
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• pp.27-36
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• 2014

Due to the latitudinal location of Korea, the seasonally frozen ground has been focused on as research topics such as the frost heaving under the asphalt road rather than the permafrost ground. However, the recent construction of the second Korean Antarctic research station, the Jangbogo station and the participation on the development of the natural gas pipeline in Russia arouse the research interests on the behavior of the permafrost ground. At the design process of the geotechnical structures on the permafrost ground, the evaluation of the creep characteristics of the frozen soil is very crucial. Since the domestic specification on the frozen soil testing does not exist currently, it is necessary to evaluate the creep characteristics of frozen soils systematically with regard to the affecting factors. Therefore, the creep characteristics of the frozen specimens of dense Jumoonjin sand were evaluated under various loads at -5 and $-10^{\circ}C$. Based on the test results, as the load became close to the strength and the temperature became lower, the duration of the secondary creep became shorter and more distinct tertiary creep responses were observed.

• Food Science and Preservation
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• v.5 no.1
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• pp.89-96
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• 1998

The antibacterial activity of clove (Eugenia caryophyllata Thumb) in culture troth against S. aureus was tested at 35, 5, -20, 50, 55 and 60$^{\circ}C$. Tryptic soy broth(TSB) containing 0∼0.5%(w/v) of clove was inoculated with 105∼107 CFU/ml of S. aureus and incubated at each temperature. The growth of S. aureus occured at 0.1% clove after a prolonged lag period while viable cells of S. aureus decreased more than 2 log cycles at 0.3 and 0.4% clove during 12 hours storage at 35$^{\circ}C$. During 32 days of refrigerated storage at 5$^{\circ}C$, survivors of S. aureus were decreased with the progress of time and increasing clove concentration. At the presence of 0.2, 0.3 and 0.4% clove, bacterial cells were dead after 32, 20 and 16 days of refrigerated storage, respectively. During 32 days of frozen storage at -20$^{\circ}C$, survivors of S. aureus were decreased less than 0.5 log cycle at 0% clove. At the presence of 0.1∼0.4% clove, survivors were decreased 2.5∼3.0 log cycles after 1 day and then decreased 0.4∼0.8 log cycles through the frozen storage. There were small changes in populations of S. aureus in TSB between different concentrations of clove during frozen storage. The D-values of S. aureus at clove 0, 0,2, 0.4% were 28.53, 15.14, 8.9 min at 50$^{\circ}C$, 18.43, 10.32, 6.74 min at 55$^{\circ}C$ and 12.78, 9.88, 5.72 min at 60$^{\circ}C$, respectively. The D-values for S. aureus were decreased with the increasing temperature and clove concentration.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.119-124
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• 1987

Combined cryoprotectants (C.C.) were formulated to depress freezing points of strawberry pulp and orange juice concentrate to ${-15}^{\circ}C$, and quality changes in fruit pulps during storage ai ${-15}^{\circ}C$ in the liquid state were investigated. C.C. suitable for strawberry pulp consisted of sucrose (2.5%, w/w), glucose (12.7%), fructose (12.7%), glycerol (1%), propylene glycol (1%) and ascorbic acid (0.1%), and that for orange juice concentrate containing 48% solids glucose (5%), fructose (5%), glycerol (4%) and citric acid (1%). When quality of fruit pulps was compared among control and those with C.C., quality of fruit pulps stored with added C.C. was at least as good as control, except treatment B which had significantly lower overall preference. Strawberry jam prepared from pulp stored for 4 monthes did not show any significant quality differences among control and treated samples. The results of this study indicated that fruit pulps could be stored with added C.C. in the liquid state at the frozen storage temperature, while maintaining qualities at least as good as the conventionally frozen stored products.

• Proceedings of the KSAR Conference
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• 2001.10a
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• pp.57-57
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• 2001

This study was carried out to investigate the general characteristics such as volume, sperm concentration, sperm motility, sperm abnormality on whole semen, RSP-S and RSP-T semen and fractional semen of small size dogs, and the effect of temperature and preservation time and cryoproservation on motility of whole and RSP-S and RSP- T semen. Multiple ejaculates were collected from small dogs by the digital manipulation of penis. 1. The volume per ejaculate semen, sperm of concentration and motility and abnormal sperm rate of 1st fractional semen were 0.65±0.09㎖, 4.52±0.35×10/sup 6/ cells/㎖, 15.64±3.85% and 5.50±0.62%. Also, 2nd fractional semen were 1.25±0.20㎖, 3.35±0.48×10/sup 6/cells/㎖, 96.25±4.65% and 4.24±0.46%. And 3rd fractional semen were 1.45±0.21㎖, 3.85±0.52×10/sup 6/cell/㎖, 92.82±4.24% and 4.66±0.58%, respectively. 2. The sperm of concentration and motility and abnormal sperm rates of whole, RSP-S and RSP-T semen were 5.45±0.82×10/sup 6/ cells/㎖, 95.55±4.65%, 4.58±0.45% and 4.82±0.36×10/sup 6/cells/㎖, 90.10±3.42%, 6.48±0.68% and 4.55±0.45× 10/sup 6/cells/㎖, 93.25±3.85%, 4.82±0.58%, respectively. 3. The motility of whole, RSP-S and RSP-T semen were higher at 4℃ than at 38℃. When preservation temperature was at 4℃, survival rates of RSP-S and RSP-T sperm were 97.54%-6.25% at 1-72 hrs, 97.40%-5.62% at 1-100 hrs, respectively. 4. The survival rates of slow and rapid frozen 2nd fraction, RSP-S and RSP-T semen were 67.3±4.45%, 88.8±4.46% and 46.4±3.84%, 74.4±4.20%, respectively. Survival rates was significantly higher in frozen RSP-S and RSP-T semen than that in control group(8.5±2.12%).