• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.296-301
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• 2009

The ice storage system uses water for low temperature latent heat storage. However, a refrigerator capacity is increased and COP is decreased due to supercooling of water in the course of phase change from solid to liquid. This study investigates the cooling characteristics of the TMA-water clathrate compound including TMA (Tri-methyl-amine, $(CH_3)_3N)$ of $20{\sim}25wt%$ as a low temperature latent heat storage material. The results showed that the phase change temperature and the specific heat is increased and the supercooling degree is decreased as the weight concentration of TMA increased. Especially, the clathrate compound containing TMA 25wt% has the average phase change temperature of $5.8^{\circ}C$, the supercooling degree of $8.0^{\circ}C$ and the specific heat of 3.499 kJ/kgK in the cooling process. This can lead to reduction of operation time of refrigerator in low temperature latent heat storage system and efficiency improvement of refrigerator COP and overall system. Therefore, energy saving and improvement of utilization efficiency are expected.

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.4
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• pp.618-623
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• 2004

This paper has dealt with the heat storage characteristics of gel type micro size latent heat storage material slurry. The heat release operation to the gel type micro size latent heat storage material slurry was carried out using hot air bubbles by direct contact heat exchange. This experiment was carried out using phase change material of n-paraffin so the heat release amount is higher than cold water system. The parameters of this experiment were concentration of latent heat phase change material, height of heat release bath and inlet velocity of hot air. The main results obtained are as follows : (1) The effect of concentration of latent heat phase change material dispersed with water is very affective to the direct contact heat exchange between hot air and gel type micro size latent heat storage material slurry. (2) It is clarified that the most effective concentration of latent heat phase change material dispersed with water exists around 20mass% at this type of direct heat exchange model experiment.

• Korean journal of food and cookery science
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• v.25 no.1
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• pp.90-97
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• 2009

Changes in the quality characteristics of doenjang prepared with a meju containing components of Acanthopanax senticosus, Angelica gigas and Corni fructus during storage were evaluated. Three types of doenjang produced using each of these components showed lower Hunter's L and a values than the values of the control during the initial stage of storage: however, these values were similar to those of the control after 60 days of storage. Doenjang containing A. gigas showed a similar degree of browning to that of the control during the early stage of storage, while the degree of browning observed in the other samples was much higher than that og the control during this period. Despite these initial differences, the browning in all samples became similar after extended storage. The level of acidity increased gradually for up to 60 days, after which it decreased slightly. The pH of all treatments decreased with storage time. The amino-N contents of all types of doenjang increased gradually, reaching peak values after 60 days. Doenjang with A. senticosus and A. gigas had a strong characteristic flavor that reduced the native flavor of doenjang. Doenjang with C. fructus showed a similar overall palatability to that of the control.

• Korean journal of food and cookery science
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• v.30 no.5
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• pp.531-539
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• 2014

The purpose of this study was to determine the storage characteristics of Makphyun, a kind of rice cake, containing peach and Makgeolli. The effect of peach paste (0, 5, 10 or 20%) on the storage qualities of Makphyun was evaluated during storage at $20{\pm}2^{\circ}C$ for 3 days. As the amount of peach paste increased, the loss of water in peach Makphyun decreased during storage. The sugar concentration ($^{\circ}Brix$) increased with the amount of peach paste. Textural properties by TPA showed that the hardness of Makphyun containing 20% peach paste was the lowest among the treated samples. However, the hardness of all Makphyuns increased during storage, regardless of the amount of peach paste. In accordance with texture results, DSC (Differential Scanning Calorimetry) showed that the enthalpy of Makphyun with 20% peach addition was the lowest, demonstrating the delaying effect of peach paste on the retrogradation of rice cake. From these results, it was determined that the addition of peach to Makphyn extends shelf-life by delaying retrogradation.

• The Korean Journal of Mycology
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• v.39 no.2
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• pp.122-125
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• 2011

The goal of this study was to provide shelf-life of Gugija-Liriope tuber raw makgeolli. After we prepared Gugija-Liriope tuber raw makgeolli by using Gugija, Liriope tuber, nuruk, cooked rice and Saccharomyces cerevisiae C-2, changes of its quality and physiological functionality were investigated during the storage at $4^{\circ}C$ and $20^{\circ}C$. Ethanol contents was decreased from 8.3% to 7.2% for storage of 9 days at $4^{\circ}C$ and 6 days storage at $20^{\circ}C$, respectively. Antihypertensive angiotensin I-converting enzyme inhibitory activity of Gugija-Liriope tuber makgeolli was increased from 63.1% to 66.0% after storage for 9 days at $4^{\circ}C$. Total acceptability of 9 days storage makgeolli at $4^{\circ}C$ was still good. In conclusion, shelf-life of Gugija-Liriope tuber raw makgeolli was 9 days at $4^{\circ}C$ in this respect of ethanol contents, antihypertensive action and total acceptability.

• Journal of the East Asian Society of Dietary Life
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• v.20 no.6
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• pp.888-895
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• 2010

Riceyeotgangjung (RYG) with added spirulina was prepared with citron juice for masking of odor. Oil temperature for puffing was found to be $220^{\circ}C$ for frying dry rice based upon the results of expansion rate and color. RYGs with added spirulina (1, 2, and 3%) were prepared under the above conditions, and their physicochemical and sensory properties were examined under storage at $60^{\circ}C$ for 15 days. Moisture content of RYG decreased proportionally with the spirulina content and storage time. The hardness levels of the freshly made RYGs with spirulina were higher than that of control. During storage, the hardness of the control gradually increased, but those of the RYGs with spirulina gradually decreased, although no significant differences existed between the spirulina containing RYGs. Lightness and redness values in the Hunter color system decreased according to the spirulina content and storage time. Yellowness value also increased with the spirulina content and storage time. Phycocyanin and total phenolic content increased with spirulina content, but decreased with the storage period. Sensory evaluation results showed that RYG with 2% added spirulina received the highest scores for color, taste, overall acceptability, and intention of purchase. As a result, the optimal addition amount of spirulina to RYG is recommended to be 2%.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.217-224
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• 2005

The storage characteristics of frozen soy yogurt prepared with hydrolyzed soy protein isolates were evaluated. In order to facilitate lactic fermentation bacteria grow and produce lactic acid as fast rate as possible, soy protein isolate(SPI) was hydrolyzed using two kinds of proteases; bromelain and a-chymotrypsin. The cultural systems employed thereafter for lactic fermentations were Bifidobacterium bifidum or B. bifidum and Lactobacillus bulgaricus. The viable cell counts, normal- and bile acid tolerances from the mixed cultures of B. bifidum and L. bulgaricus decreased sharply during the initial first 3 days of frozen storage and then showed a gradual decrease thereafter. Melt-down percent of the all frozen products have been favorably affected as was shown by less melting at raised testing temperature during 28 days of frozen storage except for the initial 3 days during which a minor change has been observed. Among the various volatile flavor components, the contents of acetaldehyde, acetone, diacetyl and methanol generally increased during the frozen storage. In sensory test, the frozen soy yogurt prepared with a-chymotrypsin and mixed culture of B. bifidum and L. bulgaricus was the most desirable, the highest scores in sourness, bitterness and mouthfeel.

• Food Science and Preservation
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• v.31 no.1
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• pp.46-63
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• 2024

This study evaluated the impact of storage temperature on the quality characteristics of texturized vegetable protein (TVP). TVP was prepared by mixing defatted Daewon soybean flour at 80℃, gluten, and corn starch in a 5:3:2 ratio, which was then extruded at a screw speed of 250 rpm and a barrel temperature of 190℃ with moisture addition at 9 rpm. Subsequently, the extruded TVP was vacuum-sealed in polyethylene packaging and stored at -20℃, 0℃, and 4℃ for 9 days. Texture analysis revealed that the curing rate followed 4℃ > 0℃ > -20℃ sequence. No significant color variation was observed across the storage conditions, although water content increased at all temperatures. Notable changes were detected in moisture absorption capacity (%) and solid leaching (%), following the order of -20℃ > 0℃ > 4℃. The turbidity of the solution released during cooking varied, with the highest to the lowest sequence being -20℃ > 4℃ > 0℃, while pH levels remained neutral. Regarding free amino acids, sweetness and textural quality improved with storage across all temperatures, whereas bitterness components diminished at 4℃. The study suggests that refrigerated storage at 4℃ is a viable method for distributing TVP, which was previously distributed only in a frozen and dry state.

• Korean journal of food and cookery science
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• v.16 no.6
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• pp.511-520
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• 2000

To investigate the effect of sugar and drying method on quality and storage characteristics of beef jerky, storage, textural and sensory characteristics were examined. Water activity was decreased as storage time was prolonged and the honey and rice syrup-added natural dried samples(N-H, N-R) were recorded the lowest value, 0.71 at five weeks of storage. During the storage period, pH values of all the samples were decreased and honey-added and heated air dried beef jerky(H-H) had the lowest pH value, 5.22. L, a, b values had a tendency to decrease, during the storage period. During the storage period, TBA values of all samples showed increasing tendency. Sugarsyrup-added samples(N-S, H-S, S-S$\^$*/) had the lowest TBA value, and those of honey-added samples(N-H, H-H, S-H$\^$**/) were highest, regardless of drying method. Total plate counts of bacteria and the number of lactic acid bacteria were increased as storage time was prolonged. Sugar syrup-added and heated air dried beef jerky(H-S) had the lowest in total plate counts of bacteria and the number of lactic acid bacteria, at five weeks of storage. Textural properties value of all samples were increased as storage time was longer. Honey-added samples showed the higest springness and cohesiveness value and sugarsyrup-added and natural dried sample showed the highest value in chewiness, gummness and hardness. In the almost sensory score of natural dried beef jerky was decreased asstorage time was prolonged, regardless of packaging method. The sensory score of heated air dried samples were higher than those of natural dried samples, regardless of packaging method. $\^$*/S-S sucrose syrup added smoking dried sample, $\^$**/S-H honey added smoking dried sample

• Korean journal of food and cookery science
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• v.19 no.3
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• pp.374-389
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• 2003

The Purpose of this study was to propose the most effective packaging method and storage conditions to apply to home-delivered meals for the elderly Changes in the physical and sensory qualities of pan fried oak mushroom and meat, soy sauce glazed hair tail and roasted dodok, in wrap packaging, top sealing and vacuum packaging were evaluated during storage at 25, 4 and -18$^{\circ}C$, for 5 days. The speed of falling-off in the foods qualities, under chilled and frozen storage conditions did not differ much as the 5 day storage period was too short for a proper assessment. The sensory characteristics of taste and texture were better evaluated in the chilled than in the frozen storage. The most effective packaging method at all the storage temperatures was the vacuum packaging, which assured the safety of the foods by the removal of oxygen. The lightness, springiness and hardness were significantly influenced by the storage temperature, period and packaging method, while the sensory characters were affected by storage temperature and the period. In conclusion, the quality of the vacuum packed pan fried oak mushroom and meat and soy sauce glazed hair tail, in frozen storage, were still fresh after the five days of the experiment. The shelf-life of those foods with wrap packaging, in chilled storage, were suggested to be three days. The quality of the roasted dodok, with vacuum packaging in chilled storage, was preserved for five days.