• Journal of the Korean Ceramic Society
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• v.56 no.3
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• pp.233-255
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• 2019

Thermal batteries are reserve batteries with molten salts as an electrolyte, which activates at high temperature. Due to their excellent reliability, long shelf life, and mechanical robustness, thermal batteries are used in military applications. A high-performance cathode for thermal batteries should be considered in terms of its high capacity, high voltage, and high thermal stability. Research progress on cathode materials from the recent decade is reviewed in this article. The major directions of research were surface modification, compounding of existing materials, fabrication of thin film cathode, and development of new materials. In order to develop a high-performance cathode, a proper combination of these research directions is required while considering mass production and cost.

• Journal of Life Science
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• v.22 no.1
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• pp.80-86
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• 2012

This study was conducted to improve quality of takju where natural honey is used to control the ripening fermentation and the amount of sediment derived from takju mash. A koji was prepared using rice starch and Aspergillus awamori var. kawachii. Takju mash was prepared by alcohol fermentation with Saccharomyces cerevisiae and a 3-step addition of steamed rice. The clean part of the mash (CPM) was separated from the sediment at $5^{\circ}C$ and 5% (w/v) of natural honey was added and then ripened for 23 days at 5, 10, or $15^{\circ}C$. Temperature, pH, acidity, and total sugar content showed no significant differences, but a 0.2 percent reduction in alcohol content occurred during storage. However, CPM ripened with honey had a comparatively higher score on sensory evaluation than did immature CPM with added honey added. Takju with 8% alcohol content was prepared by mixing the water from the mixed CPM ripened with honey together with 100, 50, and 25% of the frozen sediment. Several quality characteristics of the takju were checked over 37 days of fermentation at $10^{\circ}C$. The pH was sustained between 4.1 and 4.3, and changes in the number of viable yeast cells, acidity, total sugar amounts, and alcohol content showed similar patterns but differences in scale. Smaller amounts of sediment affected the stability of the takju. Mixing the CPM ripened with natural honey at low temperature moderately reduced the amount of sediment in the mash and resulted in a highly flavorful takju with an extended shelf life.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.270-276
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• 1993

Leaf lettuce (Lactuca sativa L., var. crispa) packed in $20{\mu}m$ LDPE (perforated), $20{\mu}m$ LDPE, $30{\mu}m$ HDPE, and $40{\mu}m$ LDPE pouches was stored at $4^{\circ}C,\;10^{\circ}C\;and\;20^{\circ}C$. The quality of leaf lettuce during the storage was investigated in terms of weight loss, color, soluble solids content, texture and sensory properties. Leaf lettuce exhibited the highest storage stability at $4^{\circ}C$. Shelf-life of the packed leaf lettuce was prolonged approximately $10{\sim}15$ times in comparision with that of the unpacked under all temperature conditions. Among the packed leaf lettuce, self-life in $20{\mu}m$ LDPE (perforated) and $20{\mu}m$ LDPE pouches was relatively short mainly due to discoloration and deterioration. On the other hand, the quality of the leaf lettuce packed in $30{\mu}m$ HDPE and $40{\mu}m$ LDPE pouches was kept well during the storage. Particularly, $40{\mu}m$ LDPE pouches conferred the shelf-life superior to other film pouches.

• Food Science and Preservation
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• v.13 no.3
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• pp.304-309
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• 2006

In order to examine the antimicrobial effect on dairy processing facilities and products, Prunus mume extinct (PME) was applied to the pilot plant system of dairy industry and yogurt, PME showed thermal and pH stability in the wide spectrum of temperature ($40{\sim}150^{\circ}C$) and pH ($4{\sim}10$) and remarkable antimicrobial activities against dairy spoilage microorganisms. As the result of aseptic treatment of dairy processing facilities with PME microbial colony including coliform bacteria was not detected canpore to those detected in the control. In the level of PME concentration which inhibit the growth of putrefactive microorganisms we could produce yogurt with good scores of sensory evaluation.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.235-239
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• 2001

In order to enhance suitable processing methods of imported Pacific saury, Cololabis saira, storage stability of seasoned-dried Pacific saury (imported product) treated with liquid smoke (T2 product) was compared with a control (C, seasoning only) and T1 (treatment of 0.05% BHT instead of liquid smoke). The histamine contents of 3 seasoned-dried products were within a stable range (9.08 ~ 12.08 mg/100 g) during storage. The water activities of all products were in the 0.698 ~ 0.755 range. The viable cell count of T2 was lower than those of C and T1 during storage. The change in color values of C, T1 and T2 were not significant with increasing storage period. The results of the sensory evaluation during storage showed that the shelf-life of T2 was extended to 60 days, while those of C and T1 were limited to up to 45 days.

• Journal of Microbiology and Biotechnology
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• v.32 no.12
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• pp.1599-1604
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• 2022

Storage stability of freeze-dried lactic acid bacteria is a critical factor for their cost-effectiveness. Long-term storage of lactic acid bacteria enables microbial industry to reduce distribution costs. Herein, we investigated the effect of cold adaptation under supercooling conditions at -5℃ on the viability of Leuconostoc mesenteroides WiKim32 during the freeze-drying process and subsequent storage. Cold adaptation increased the thickness of exopolysaccharides (EPS) and improved the viability of freeze-dried Leu. mesenteroides WiKim32. Compared to non-adapted cells, cold-adapted cells showed a 35.4% increase in EPS thickness under supercooling conditions. The viability of EPS-hydrolyzed cells was lower than that of untreated cells, implying that EPS plays a role in protection during the freeze-drying process. Cold adaptation increased the storage stability of freeze-dried Leu. mesenteroides WiKim32. Fifty-six days after storage, the highest viability (71.3%) was achieved with cold adaptation at -5℃. When EPS-containing broth was added prior to the freeze-drying process, the viability further increased to 82.7%. These results imply that cold adaptation by supercooling pretreatment would be a good strategy for the long-term storage of Leu. mesenteroides WiKim32.

• Food Science and Preservation
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• v.11 no.3
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• pp.394-399
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• 2004

The effects of gamma irradiation to improve the hygienic quality and microbiological shelf stability of whole baked egg were investigated by comparison with autoclaving process. The contamination levels of coliform, total aerobic bacteria and fungal group in a fresh egg were 10$^{5}$ CFU/g, 10$^{2}$ CFU/g and 10$^{1}$ CFU/g, respectively. After baking process, total aerobic bacteria and fungi were not exceeded to 10$^{1}$ CFU/g. Also, coliform was not detected under the aseptic process. However, cell counts of the baked egg after packaging reached to 10$^{4}$ CFU/g of total aerobic bacteria, 10$^{1}$ CFU/g of coliform, and 10$^{2}$ CFU/g of fungi. Therefore, it was assumed that microbial contamination of baked and packaged egg was mainly originated from an environmental uptake during packaging process. Microbiological shelf stability of the non sterilized control was about a week. Whereas, the baked eggs irradiated at more than 5 kGy were stable over 12 weeks at ambient condition as like those being autoclaved. Analytical texture profIle was stable within 10 kGy, but it became hardened in the sample treated with autoclaving. About 67$\%$ of panelists identified a sensory difference between non-irradiated and 10 kGy-irradiated sample. The baked egg irradiated at 10 kGy and autoclaved had lower acceptability than the control or samples irradiated lower than 5 kGy. Therefore, it was considered that optimal irradiation dose for radiation sterilization of baked and packaged egg was 5 kGy. At that point, it was recommended that appropriate microbiological shelf-life was 12 weeks at ambient condition.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.380-395
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• 2022

This study investigated the utilization of detoxified Rhus verniciflua (RV) extract as a natural antioxidant to extend the shelf life of chicken breast meat during storage. Pre-heating at (35℃, 100℃, 120℃, and 140℃) was conducted on heartwood of RV prior to extraction to improve its antioxidant activity and remove the allergenic compound urushiol. The antioxidant activity was the highest when RV pre-heated at 120℃ with the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) scavenging activity observed at 62.29 EC₅₀ ㎍/mL and 12.11 IC₅₀ mg/mL, respectively. Pre-heating also significantly increased the total phenolic content (TPC), with the highest improvement was seen at 120℃, 100℃, and 140℃ respectively, wherein 35℃ shared no difference with the raw RV (RRV). Urushiol content was vanished following pre-heating at 120℃ and 140℃. With respect to these result, pre-heating treatment at 120℃ was applied before the extraction of the heartwood of RV. Prepared breast meat sample was dipped into distilled water as a negative control, 0.02% butylated hydroxytoluene (BHT) as positive control, and a solution containing detoxified RV extract (0.10%, 0.25%, 0.50%, 1.00%) at 4℃ for 60 min. Treatment group with 0.50% and 1.00% addition increased the redness and yellowness value on day 6 and day 3 of storage respectively (p < 0.05). The pH value of breast meat was also increased in treatment of 0.50% and 1.00% on day 0, but subsequently lower until end of storge day compared to control negative (p < 0.05). Furthermore, 0.50% treatment exhibited a higher antioxidant activity, stronger inhibition of the microbial growth evaluated by total viable count and maintaining a lower total volatile basic nitrogen among treatments (p < 0.05), unless for BHT and 1.00% treatment groups (p > 0.05). It indicates a similar efficacy of detoxified RV extract with that of positive control treated with BHT. The results of this study suggested that dipping chicken breast meat into a solution containing 0.50% of previously pre-heated RV heartwood at 120℃ could be a promising natural antioxidant for extending the shelf life, and at the same time improve its quality during storage.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.737-741
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• 1988

The storage stabilities of philipines' bananas were investigated according to the storage pretreatments and packaging methods during 60 days storage at $13^{\circ}C$. The better storage stability was got in bananas packaged with 60{\mu}m low density polyethylene (PE) film inside the carton box than those without inside pack. Radiation gave the adverse effects on bananas' storage stabilities. Shelf-life of bananas in PE package was 60 days, but that of radiated bananas was only 20 days. And shelf-life of bananas in no inner pack was 20 days. Soluble solid content of bananas packaged with PE film was 17 Brix degree after 60 days storage, but that with no inner package was around 20 Brix after 20 days. Color was below 3 in color chart after 60 days storage and hardness was rapidly decreased from 40 days in bananas packaged with PE film, but color was became to 3 color after 30 days and hardness was rapidly decreased after 20 days in bananas without inner package. Percentage of deteriorated bananas were below 3% in PE films after 60 days storage, but 100% after 40 days in bananas without inner package.

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.45-51
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• 1988

To improve the individual packaging method and extend the shelf life of hair tail(Trichiurus japonicus), salted an unsalted hair tail chunk (cut in 8-10cm) were packaged in laminated plastic film bag(Nylon/PE: $20{\mu}m,\;12{\times}15cm$) filled with with free-$O_2$ absorber, in vacuum, and stored at 0 and/or $5^{\circ}C$. The other samples were packaged in plastic foam trays, overwraped with oxygen permeable film(control), and stored at same temperature. Volatile basic nitrogen (VBN), trimethylamine (TMA) and viable cell counts (VCC) were progressed with increase of storage time, but thiobarbituric acid (TBA) values decreased gradually after reaching at a maximum peak in 5-15 days. Judging from 4 chemical components, VBN was the most available component in quality judgement of hair tail chunk and its upper limiting content was 29 mg%. Regression equation for shelf life prediction of hair tail chunk with sensory evalution and VBN component was determined.