• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.45 no.6
• /
• pp.635-639
• /
• 2012

Thawing is very important in tuna canning because it affects the yield and quality of the canned tuna, and productivity. The effects of vacuum thawing on the quality, yield, and thawing times of frozen skipjack were compared with conventional water immersion thawing. The time required to thaw frozen skipjack tuna (weight 2.5-3.0 kg) from $-10^{\circ}C$ to $-2^{\circ}C$ was 75, 60, and 37 min at a pressure of 17, 23, and 31 mmHg, respectively, corresponding to temperatures of 20, 25, and $30^{\circ}C$. The thawing time decreased with increasing pressure. Vacuum thawing shorten the thawing time by 58-80% compared with water immersion thawing at $20^{\circ}C$, and there was less difference between the core and skin temperatures than with water immersion thawing. No significant change in pH or histamine was observed according to thawing method, while the volatile basic nitrogen (VBN), trimethylamine (TMA), and K value were lower with vacuum thawing than water immersion thawing. Based on these results, we believe that vacuum thawing minimizes the biochemical and microbial changes that occur while thawing frozen skipjack tuna.

• Korean journal of food and cookery science
• /
• v.19 no.6
• /
• pp.758-764
• /
• 2003

This study was performed to determine the quality characteristics of mixed polysaccharide gels made from kcarrageenan and locust bean gum with various kiwifruit content after freeze-thawing. The syneresis, rupture properties, TPA properties and sensory properties of the mixed polysaccharide gels with various kiwifruit contents after freeze-thawing were measured. The syneresis of the gel with various kiwifruit contents by freeze-thawing was not significantly different, whereas repeating freeze-thawing resulted in remarkable increase in the syneresis of the mixed polysaccharide gels with 5％, 20％ and 40％ kiwifruit. In terms of the rupture properties, the rupture stress, rupture energy and rupture strain decreased with increasing kiwifruit content after freeze-thawing. In terms of the TPA properties, the adhesiveness, hardness and chewiness increased and the cohesiveness decreased with increasing kiwifruit content after freeze-thawing. The rupture properties, springiness and cohesiveness of the gel by freeze-thawing were lower than those of the gel stored in the refrigerator. In contrast, the gumminess, hardness and chewiness of the gel after freeze-thawing were higher than those of the gel stored in the refrigerator. The results showed that the gel became crumbly and tough as a result of freeze-thawing. In the sensory evaluation, He overall acceptability of the gel after freeze-thawing was highest at the 30％ kiwifruit content, and differences in the sensory properties between the gel after freeze-thawing and that stored in the refrigerator were small. Therefore, mixed polysaccharide gels with kiwifruit after freeze-thawing could be useful despite the small decrease in quality.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.1
• /
• pp.100-108
• /
• 2016

In this study, a survey was conducted to both evaluate the consumers' general attitudes for purchasing and storing the raw chicken and determine the thawing practices used for defrosting frozen chicken at home. About 75% of the consumers indicated purchasing chicken meat at least once a week or more. Furthermore, the majority (82.16%) of those who stored at least a portion of the raw chicken stated freezing the raw chicken meat at home. Freezing the chicken meat was considered to have no effect on the quality by 43.49% of the consumers while 56.51% thought that freezing had either negative or positive effects on the quality. The survey study indicated that top five most commonly used thawing practices included thawing on the kitchen counter, thawing in the refrigerator, thawing in the warm water, thawing in the microwave, and thawing under tap water. In addition, an experimental study was conducted to determine the effects of these most commonly used thawing practices on some quality characteristics of the chicken meat including pH, drip loss, cooking loss, color analysis and textural profile analysis. Although, $L^*$ value for thawing on the kitchen counter was the lowest, after cooking, none of the thawing treatments have a significant effect on the color values. Thawing in the microwave produced the highest drip loss of 3.47% while the lowest drip loss of 0.62% was observed with thawing in the refrigerator. On the other hand, thawing in the microwave and refrigerator caused the lowest cooking loss values of 18.29% and 18.53%, respectively. Nevertheless, there were no significant differences among textural parameter values of the defrosted and then cooked samples using the home based thawing practices, indicating similar quality characteristics among the samples.

• Journal of Fisheries and Marine Sciences Education
• /
• v.28 no.4
• /
• pp.1152-1158
• /
• 2016

This study was used samples, mackerel (Scomber japonicas), Japanese Spanish mackerel (Scomberomorus niphonius), alaska pollock (Theragra chalcogramma), yellow croaker (larimichthys crocea) known as some of the major species fisheries products in Korea We were investigated temperature change during thawing processing, water holding capacity, drip loss, extractive-nitrogen and viable cell count by various thawing methods, thawing at the room temperature (TRT), hot-air thawing (HAT), aeration thawing (AT), high-frequency thawing (HFT). The temperature changes have taken 2~3 hours in HFT and 24 hours by TRT. The expressible drip loss was 0.47~0.87 g/100 g in HFT, 1.91~4.42 g/100g in TRT, 1.31~4.93 g/100g in HAT, and 2.01~4.59 g/100g in AE. The water holding capacity was higher samples thawing by HFT than other thawing methods. Extractive-nitrogen was 276~452 mg/100 g in HFT, 177.21~420.27 mg/100 g in TRT. Viable cell count was $10^2$ to $10^3$ in HFT, $10^3$ to $10^5$ in other thawing methods. The processing speed and uniformity by HFT was minimized the risk of product degradations (drip losses, deterioration of sensorial, chemical and physical characteristics, bacteria growth, etc.), thus helping to preserve at its best the product quality than those by thawing methods. Therefore, HFT was expected to make high-quality thawing products anticipate future thawing technology

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.1
• /
• 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.

• Journal of Embryo Transfer
• /
• v.14 no.2
• /
• 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.

• Korean Journal of Food Science and Technology
• /
• v.22 no.2
• /
• pp.123-128
• /
• 1990

In order to establish the optimal thawing condition of frozen fork, hot-air thawing and microwave thawing were evaluated at various conditions. In hot-air thawing, the higher the air temperature and the lower the meat surface temperature, the grater the thawing rate was. In microwave thawing, the grater the power and the lower the meat core temperature, the faster the thawing rate was. Comparing the two methods, microwave thawing was found to be significantly faster than hot-air thawing. TBA value and cooking loss were higher in hot-air thawing than that of refrigeration thawing or microwave thawing. Total extractable protein tended to be lower in hot-air thawing than that of the other two thawing methods. WHC decreased with the increase of hot-air and meat surface temperature whereas no significant difference was observed in microwave thawing regardless of the thawing conditions. Total microbial counts of thawed meat by the hot-air or microwave thawing were lower than that of refrigeration thawing.

• Journal of the Korea Concrete Institute
• /
• v.11 no.4
• /
• pp.117-127
• /
• 1999

In concrete incorporating high volume ground granulated blast-furnace slag that has frozen at early age, to evaluated the results of resistance to freezing and thawing is very difficult because the hydration of the concrete increases over the duration of rapid freezing and thawing test. Hence, the dynamic modulus of elasticity of specimens after freezing and thawing will be favorable results unless the hydration effect is taken into consideration. In this study, a method of evaluating to the resistance to freezing and thawing of concrete subjected freezing at early age, in which the effect of hydration is modified for its increase during rapid freezing and thawing test, is investigated.

• Journal of the Korean Society of Industry Convergence
• /
• v.21 no.6
• /
• pp.301-307
• /
• 2018

This paper deals with the development of the high frequency thawing machine. The fishery products caught over the world are kept frozen to maintain freshness. These fishery products require thawing before they are sold to customers as food. However, the thawing process can cause freshness reduction, drip coming out, quality deterioration, discharging polluted water, as well as a lot of space and time. The high frequency thawing machine developed to solve this problem has a narrow space, a short thawing time and a small drip. The developed high frequency thawing machine can be used in many fields such as fish processing plant, livestock processing plant. This paper describes the design of the high frequency thawing machine by developing the high frequency generator, development of the controller, and the design of mechanism, and shows the superiority of the high frequency thawing machine by the performance evaluation.

• Korean Journal of Food Science and Technology
• /
• v.31 no.1
• /
• pp.54-61
• /
• 1999

A study was conducted to find a rapid thawing method which prevents excessive drip loss and local overheating. Effects of thawing methods (conventional thawing vs. 2,450 and 915 MHz microwave thawing) on thawing time, temperature profile, drip loss, water holding capacity, total color difference and total aerobes were investigated. Samples were thawed at 4, 28 and $50^{\circ}C$ in a refrigerator or an oven for the conventional thawing methods the convertional thawing methods. Power levels of 5, 10 and 15 kW were used for 915MHz microwave thawing. Cotreatment of 915 MHz microwave and convectional heating $(120^{\circ}C)$ was tested. 915 MHz microwave accelerated the thawing rate, and showed significant effects on penetration depth, drip loss, water holding capacity and total aerobes. Cotreatment of 915 MHz microwave and convection heating was appeared to be a suitable thawing process for the food industry.