• 한국식품영양과학회지
• /
• 제29권1호
• /
• pp.15-19
• /
• 2000

Physicochemical properties of frozen immatured soybean (Miwon) under various thawing conditions were investigated. The moisture content, density and other chemical compositions were not affected by the thawing conditions. Thelightness of soybean and soybean hull decreased when thawing with 1$0^{\circ}C$ water while it increased when other thawing conditions used. Hardness and vitamin C content decreased with all thawing conditions ; especially decrease in vitamin C content was severe with microwave thawing. Lipoxygenase activity was significantly decreased when thawing with microwave and 1$0^{\circ}C$ water. It was recommended that thawing with 1$0^{\circ}C$ water was the most apropriate method in terms of overall quality.

• 한국수정란이식학회지
• /
• 제14권2호
• /
• pp.131-137
• /
• 1999

This experiment was carried out to investigate the effects of osmolarity of thawing diluents, seminal plasma added in thawing diluents on the sperm viability and the effects of thawing temperature, the temparature of the thawing diluents on the sperm viability and acrosomal morphology of boar spermatozoa by the straw method. The result obtained were summarized as follows: 1. The sperm viablilty after thawing of the frozen semen was shown greater in the high osmolarity(392~492mOsm) than low osmolarity(300mOsm) in thawing diluent. The added levels of seminal plasma in thawing diluent did not affect the viability of frozen-thawed boar semen. 2. In terms of thawing temperature, the sperm viability was shown higher in the frozen semen thawed at 5$0^{\circ}C$ for one min. (p<0.01) than those thawed at 2$0^{\circ}C$ or 37$^{\circ}C$ for one min. The sperm viability was not significant at the diluent temparature of 2$0^{\circ}C$or 37$^{\circ}C$ after thawing: but the sperm viability was higher in thawing diluent at 2$0^{\circ}C$ than in that at 37$^{\circ}C$. However, the effects of thawing temperature and diluent solution on normal acrosomal rate were not significant. 3. Cleavage rates of oocytes fertilized with frozen semen were 46.4% and 43.3%, respectively, which were thawed at 5$0^{\circ}C$ for one min. and then diluted in mBTS medium at 2$0^{\circ}C$or 37$^{\circ}C$. To sum up, the sperm viability was shown greater at the high of thawing diluents of frozen boar semen. In terms of thawing conditions, the sperm viability was shown greater, when semen was thawed at a high temperature for a short time and then diluted at the same temperature as that in the straw.

• 동아시아식생활학회지
• /
• 제25권5호
• /
• pp.893-901
• /
• 2015

This study investigated the effects of thawing conditions on physiological activities and quality of peeled garlic. Peeled frozen garlic was analyzed after thawing at low temperature ($4^{\circ}C$), room temperature ($20^{\circ}C$), tap water ($20^{\circ}C$), radio frequency of 27.12 MHz, and 2.45 GHz in a microwave. As a result, the time required to thaw garlic to $0^{\circ}C$ by various thawing methods was shortest at2.45 GHz in a microwave, followed by $20^{\circ}C$ tap water, radio frequency of 27.12 MHz, $20^{\circ}C$, and $4^{\circ}C$. Microwave thawing was faster than other methods, but it resulted in significant non-uniformity of heating. The hardness of peeled garlic significantly decreased upon freeze-thawing, whereas it showed improved hardness upon radio-frequency thawing. Total color difference in garlic increased upon freeze-thawing, and it was not improved by various thawing methods. Antioxidant activities were determined for DPPH radical scavenging ability, SOD-like activity, and reducing power. Total phenolic compounds and flavonoids in garlic extract were measured as $3.222{\pm}0.214{\mu}g$ GAE/g and $0.149{\pm}0.03{\mu}g$ QE/g, respectively. The content of total phenolic compounds was significantly reduced by 2.45 GHz microwave thawing ($1.90{\pm}0.02{\mu}g$ GAE/g); however, flavonoid contents were slightly reduced under freezing and thawing conditions. The DPPH radical scavenging ability of garlic extracts was not affected by thawing methods; however, SOD-like activity and reducing power were slightly reduced by freeze-thawing. These results indicate that physiological activities were not improved by radio-frequency thawing; however, thawing time and maintain hardness were reduced compared with conventional thawing methods.

• 한국수산과학회지
• /
• 제37권3호
• /
• pp.175-178
• /
• 2004

We here report that the muscle of 'gukmeri-bok' puffer fish (Takifugu vermicularis radiatus) is intoxicated after freezing and thawing processes even though it is not toxic when it is fresh. This study was carried out to investigate the effect of different freezing and thawing conditions as well as the effect of the presence of skin or viscera on the intoxication of muscle of 'gukmeri-bok' puffer during freezing and thawing process. As a result of this investigation, thawing condition, but not freezing conditions or periods played an important role in muscle intoxication. Tetrodotoxin secretory grands exist in the skin of toxic puffer fish, the skin was more responsible for the muscles intoxication than the viscera during the freezing-thawing process. In other words, no toxicity was measured in the muscle of skinned-frozen specimens even when thawed. According to this result, it is recommended that the skin and viscera must be removed before being frozen for edible purpose. Otherwise, when a whole fish should be frozen, alternative half-thawing and removal of skin from frozen specimens is recommended.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 2001년도 학술발표회 발표논문집
• /
• pp.185-188
• /
• 2001

In this study, the characteristics of freezing and thawing resistance, the compressive strength, and the change in height of cement mortar according to a steam and taler curing conditions has been studied. To this end, the major test variables include the period of the early curing, curing temperature and the later curing. The strength test as well as volume variousness have been conducted to explore the characteristics of freezing and thawing resistance on the curing conditions. The experimental results can be efficiently used to improve the characteristics of freezing and thawing resistance for concrete products carrying steam curing.

• 한국식품과학회지
• /
• 제22권2호
• /
• pp.123-128
• /
• 1990

여러 가지 해동방법 중에서 비교적 급속해동을 할 수 있는 열풍해동방법과 microwave 해동방법으로 냉동 돈육을 해동하여 해동육의 이화학적 성질을 조사하였으며, $4^{\circ}C$ 냉장해동육의 이화학적 성질을 비교하여 최적 해동방법을 모색하고자 하였다. 열풍온도를 높이고 해동육 표면온도를 낮출수록 열풍해동속도는 빨랐으며, microwave 해동시에는 출력이 크고 해동육심부온도가 낮을수록 해동속도가 빨랐다. 이 때 microwave 해동방법은 열풍해동방법보다 유의적으로 빠른 해동속도를 보였다. $4^{\circ}C$ 냉장해동육의 TBA가와 microwave 해동육의 TBA가는 유사하였으나 열풍해동육인 경우에는 열풍온도가 높아질수록 TBA가는 유의적으로 높았다. Microwave해동육의 가용성단백질추출성은 $4^{\circ}C$ 냉장해동육과 유사하였지만 열풍해동육보다는 높았다. 해동육의 보수성과 조리손실과의 관계는 고도의 상관성을 나타냈으며, microwave 해동육이 열풍 해동육보다 보수성이 좋았고 조리손실은 줄었다. 육표면에 존재하는 세균수는 $4^{\circ}C$ 냉장해동육에서보다 열풍 해동육과 microwave 해동육에서 적었다. 이상의 결과에서, 냉동육을 해동할 때, 육량감소를 줄이고 해동육의 기능성을 좋게 유지할 수 있는 해동조건으로서는 열풍해동에서는 $50^{\circ}C$ 열풍으로 육표면온도를 $25^{\circ}C$까지 해동시킬 때가, microwave로 해동하면 195W의 출력으로 육심부온도를 $-2^{\circ}C$까지 해동시키는 것이 가장 좋은 것으로 나타났다.

• 한국식생활문화학회지
• /
• 제20권2호
• /
• pp.253-260
• /
• 2005

This study was conducted to investigate performance of methods for cooking and thawing frozen cooked rice to retard retro-gradation of cooked rice. For this research, That was executed rice's physicochemical and sensory characteristics test through the way of boiling rice or thawing, and found out best way for retro-gradation and taste. This study showed the rice cooked by pressure rice pot has less dehydration during freezing and thawing, and thawed rice by micro wave has less dehydration. Repetition of freezing and thawing resulted increasing of hardness and chewiness, and decreasing of adhesiveness and cohesiveness. The rice cooked by convotherm oven or pressure rice pot has less increased hardness while freezing and thawing. Adhesiveness was superior when rice was cooked by pressure rice pot. The rice thawed by microwave had more hardness than thawed in room temperature.

• 한국축산식품학회지
• /
• 제18권2호
• /
• pp.142-148
• /
• 1998

This study was conducted to investigate the quality change of beef muscle, which was thawed by different thawing rate in order to utilize it as fundamental data for establishing optimal and thawing condition. Chilled beef round which was purchased at a commercial market was used. The samples were frozen for 30min(time required to pas through the maximal ice forming zone, -1$^{\circ}C$∼-7$^{\circ}C$) and the thawing conditions were 3.9cm/hr, 0.21cm/hr, 0.13cm/hr. Thawing losses of rapidly thawed meat(3.9cm/hr) were significantly(p＜0.05) lower(6.10%), but cooking and total losses were the highest as 48.17% and 56.44%, respectively(p＜0.05). Characteristics such as color, flavor, texture and overall quality at different the thawing rates showed similar scores, but slightly increased after storage for 24hr. Juiciness of rapidly thawed meat was significantly(p＜0.05) higher than that compared to the other thawing rates.

• 농업과학연구
• /
• 제21권2호
• /
• pp.133-141
• /
• 1994

냉동식품을 해동하는데 적절한 해동시간과 최적해동방법을 규명하고자 감자전분, 옥수수전분 및 대두단백질을 일정비율로 혼합한 모형식품을 시료로하여 실온, 열풍 및 초단파 가열방법으로 해동하였을 때의 조직과 색의 변화 및 Drip올 측정 하였다. 동결된 모형식품의 Hardnesss는 수분함량이 적을수록 증가 하였고 단백질이 전분보다 더 낮았다. 일정성분비의 (P4S2) 해동율은 각각 실온해동 ; 0.02 kg/min, $50^{\circ}C$ 열풍해동 ; 0.08 kg/min, 초단파해동 ; 0.01kg/min)였다. 염, 당농도에 따른 조직특성은 그 첨가량에 비례하여 감소하였으며 각각 실온에서 해동완료시간이 대조구는 60분, 5% sucrose는 50분, 10% sucrose는 30분, 5% Nacl은 40분, 10% Nacl은 30분으로 나타났다. Drip발생량은 단백질 식풍은 해동초기에 수분을 흡수하는 경향을 보였으며, 전분질 식품은 수분과 전분이 많을수록 각 해동방법에서 많은 양의 유출을 보였다. 대조구의 Drip유출량은 자연해동이 22.5%, 초단파 해동이 1.3%였으나 $50^{\circ}C$ 열풍해동은 거의 없었으며, 색특성은 자연해동시 L, a, b 값의 변화가 적었고, 급속해동시에는 초단파해동이 가장 적절한 것으로 나타났다.

• 한국식품위생안전성학회지
• /
• 제3권1호
• /
• pp.19-26
• /
• 1988

Most of meat spoilage bacteria area Gram negative, which are very sensitive to freezing ; for instance , 90% of E. coli cells are killed or sub-lethally injured by freezing at -3$0^{\circ}C$, and the freeze-injury rate is dependent upon freezing rate. Since the injured bacterial cells are sensitive to selective agents, they fail to multiply in selective media. Injured bacterial cells are, however, capable of spontaneous repair at appropriate environmental and nutritional conditions . Enumeration of injured bacterial cells involves artificial induction of repair at these conditions. Cubic beef samples(3$\times$3$\times$3cm) were frozen at -6$0^{\circ}C$, -4$0^{\circ}C$, or -18$^{\circ}C$. The samples frozen at each temperature were thawed at 4$^{\circ}C$, 2$0^{\circ}C$, or by microwave . After these respective freezing an thawing treatments, the percentage of sub-lethally injured total coliforms out of total surviving ones was measured and compared. The results were as follows: 1. The interaction between freezing and thawing on injury rate was not significant. 2. The injury rates(as means of all three thawing treatments post-freezing) by freezing at -6$0^{\circ}C$, -4$0^{\circ}C$, or -18$^{\circ}C$ were 32.2$^{\circ}C$ and 19.2$^{\circ}C$ respectively . 3. The injury rates(as means of all three freezing treatments)by thawing at 4$^{\circ}C$, 2$0^{\circ}C$, or by microwave were 49.3%, 11.7% and 21.0% respectively. The highest injury rate was caused by freezing at -6$0^{\circ}C$ and subsequent thawing at 4$^{\circ}C$. However since the injury rates by freezing treatment were not significantly different, freezing at -18$^{\circ}C$ and subsequent thawing at 4$^{\circ}C$ can also be recommended , from an economic perspective.