• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.120-124
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• 2011

Predictive mathematical models were developed for predicting the kinetics of growth of Listeria monocytogenes in smoked salmon, which is the popular ready-to-eat foods in the world, as a function of temperature (4, 10, 20 and $30^{\circ}C$). At these storage temperature, the primary growth curve fit well ($r^2$=0.989~0.996) to a Gompertz equation to obtain specific growth rate (SGR) and lag time (LT). The Polynomial model for natural logarithm transformation of the SGR and LT as a function of temperature was obtained by nonlinear regression (Prism, version 4.0, GraphPad Software). Results indicate L. monocytogenes growth was affected by temperature mainly, and SGR model equation is $365.3-31.94^*Temperature+0.6661^*Temperature^{\wedge^2}$ and LT model equation is $0.1162-0.01674^*Temperature+0.0009303^*Temperature{\wedge^2}$. As storage temperature decreased $30^{\circ}C$ to $4^{\circ}C$, SGR decreased and LT increased respectively. Polynomial model was identified as appropriate secondary model for SGR and LT on the basis of most statistical indices such as bias factor (1.01 by SGR, 1.55 by LT) and accuracy factor (1.03 by SGR, 1.58 by LT).

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1316-1323
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• 2016

The aim of this study was to evaluate proteolytic and antioxidant activities of fresh pineapple and kiwi juices extracted using a slow-speed masticating household juicer during low temperature storage. While over 90% of vitamin C and total polyphenols in both juices were retained after storage for 30 days at $-20^{\circ}C$, reduction of 56.8% for vitamin C and 31.9% for total polyphenols in pineapple juice were detected after storage at $4^{\circ}C$. In the case of kiwi juice, 32.9% of vitamin C and 22.4% of total polyphenols were lost. A high initial content of vitamin C in kiwi juice resulted in a slower reduction rate than that for pineapple juice. A similar result was obtained for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Proteolytic activities of both juices were maintained efficiently with less than 10% loss during storage for 30 days at $-20^{\circ}C$. Protease stability of pineapple juice was better than that of kiwi juice during storage at $4^{\circ}C$, and the same result was obtained when boiled chicken breast was used as a substrate. From these results, when storing pineapple and kiwi juices, which are widely used as a natural meat tenderizer and digestive aid, cold storage at $-20^{\circ}C$ seemed to be more suitable for maintaining antioxidant and proteolytic activities than cold storage at $4^{\circ}C$.

• Herbal Formula Science
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• v.20 no.2
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• pp.29-35
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• 2012

Objectives : To provide the information of preservation method for herbal decoction, we evaluated the anti-inflammatory effects according to preservation temperature and period of Pyungwi-san (PWS, Ping wei-san) decoction. Methods : The anti-inflammatory activity of PWS was investigated by carrageenin-induced paw edema in SD rats. At 0 month, PWS extract was administrated 100, 300 and 1000 mg/kg/day orally for seven days prior to induction of edema. Edema was induced by subcutaneous injection of 1% carrageenin into the right hind paw. The paw volume was measured at 4 hr following carrageenin-induced paw edema in rats. At 6 and 12 months, PWS extracts according to preservation temperatures (room temperature, $4^{\circ}C$ and $-20^{\circ}C$) were administrated in rats and then carrageenin-induced paw edema volume was measured. Results : PWS showed inhibitory effect on carrageenin-induced paw edema in rats and the optimal dose was 1000 mg/kg/day at 0 month of storage. At 6 month of storage, PWS storaged at $4^{\circ}C$ and $-20^{\circ}C$ were inhibited paw edema but that storaged at room temperature was not reduced paw edema in rats. Conclusions : These results suggest that PWS decoction pouch has anti-inflammatory activities at both $4^{\circ}C$ and $-20^{\circ}C$ during 6 month storage.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.293-297
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• 2012

Of the 169 strains of microorganisms stored in Polar and Alpine Microbial Collection of Korea Polar Research Institute, 27 strains were selected for their chitinase activity on ZoBell plates supplemented with 0.4% colloidal chitin. Among them, PAMC 21693 strain have shown the highest chitinolytic enzyme activity toward pNP-$(GlcNAc)_1$ at low temperature and the highest growth rate at $4^{\circ}C$. We cloned a full-length chitinase gene of 2,857 bp which contains an open reading frame of 2,169 bp encoding 872-amino acid polypeptide. Recombinant chitinase protein was expressed in E. coli and its molecular weight was confirmed 96 kDa. In this paper, we suggest the potential use of cold-active chitinase from polar microorganisms in the field of biotechnology.

• KSBB Journal
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• v.21 no.4
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• pp.306-311
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• 2006

Cell preservation is indispensable in animal cell culture process and should be established according to the cell characteristics. In this study, we experimented hypothermic preservation of CHO cells that is widely used in pharmaceutical industry to produce therapeutic proteins and established a stable method of preservation. The highest viability of CHO cells was obtained when the cells were preserved using rolling tube, which means the cells should be suspended to avoid the cell lumping during the preservation. Also, we obtained superior preservation result under the anaerobic condition. To evaluate the serum-free media as a preservation solution, we investigated cell growth after hypothermic preservation using serum-free media. High cell viability and normal cell growth was observed during 10 days using serum-free media. Moreover, we found that more effective preservation when ${\alpha}$-tocopherol and retinoic acid is added to media as an additive. In the case of 1 liter large scale hypothermic preservation using established protocol, cell viability and growth rate was obtained as good as small scale one. This study is considered to be helpful for hypothermic preservation of CHO cells and large scale hypothermic preservation may be available through the further studies.

• Journal of Animal Science and Technology
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• v.51 no.2
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• pp.163-170
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• 2009

Colostrum provide a complete diet for the newborn calves. In ruminants, colostrum is also the sole source of initial acquired immunity for the offspring. Colostrum, therefore, plays an important role in ruminants host defense. Bovine colostrum imparts passive immunity to newborn calves during the first 24h of life and generally has been fed for the first 3 days after birth. Colostrum can be preserved conveniently for future use by brief refrigeration, freezing, or storage at ambient temperatures (fermentation or chemical treatment). Colostrum management were surveyed via data collection from 67 dairy farms in Gyeonggi and Chungnam provinces. After parturition for five days the total amount of produced colostrum was 80.4 kg on average, and the average amount of lactation fed to a calf was 20.9 kg. According to the survey results, identified treatment methods for surplus colostrum are as follows; disposal 17.9%, other calf feeding 37.3%, storage 22.4%, other livestock feeding 20.9% and other treatment 1.5%. For improvement in the quality of colostrum, there must be controlled usage of medicines (such as antibiotics) before and after parturition, proper choices of milk-drying agents, and increased milking yields during the early stage of the milking period.

• Journal of Conservation Science
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• v.29 no.4
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• pp.333-343
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• 2013

The exhibition hall of museum has been damaged by abundant dust and mold of the air in the room. Occurrence of microorganisms on the surface of the cultural heritage will cause damages such as coloration, materials degradation, deterioration, etc. In this study, we investigated the temperature/humidity and microbes distribution in exhibition hall, display showcase, and on surface of wall paintings in the Muwisa museum. From some samples collected in exhibition hall and display showcase, we identified so many varieties of micro-organisms such as Aspergillus sp., Penicillium sp., Cladosporium sp.. In particular, we could see a large number of microorganisms in the number 1, 2 exhibition hall compared with the number 3 exhibition hall. The results examining the distribution of the temperature and humidity were showed as $28{\pm}4^{\circ}C$ and 70~80%, respectively. The number 1 exhibition showcase was higher humidity environment than the number 2, 3 exhibition hall compared to the distribution ratio, which considered as correlation with the distribution of microorganism concentration. As these results, we understood that high temperature and humidity in the exhibition hall and display showcase of the Muwisa museum were characteristics caused by environmental management and hermetically-sealed rooms.

• Korean journal of food and cookery science
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• v.23 no.5
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• pp.635-643
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• 2007

This study was carried out to investigate the quality of cooked rice prepared by-an electric pressure cooker (EPC) and an electric cooker (EC) during storage at different temperatures. Four rice cultivars were used (Ilpoom, Saechucheong, Sindongjin, and Sura). The cooked rice samples were stored at room and warm temperatures for 48 hr, and at refrigerator temperatures for 10 days. Immediately after cooking, the moisture content of the EPC rice was lower than that of the EC rice; yet pH was higher for the EPC rice. The L-value of the EPC rice was reduced due to an increasing b-value. The overall acceptability of the EPC rice was high; in particular, it scored high for a roasted nutty flavor and texture. During storage, moisture content and pH decreased regardless of the cooking method. L-, a- and b-values were similar at room and refrigerator temperatures over the entire period, whereas the a-value (greenness) of the EC rice stored at warm temperature slightly decreased and the b-value (yellowness) increased after 24 hr, resulting in a decreasing L- value. Also, sensory characteristics were not significantly different for the samples stored at room temperature for 48 hr; however, at warm and refrigerator temperatures, the sensory characteristics were significantly different after 24 hr and 3 days, respectively. In conclusion, the quality of the cooked rice was effectively preserved during storage at room temperature, and qualify deterioration oaf dependent on using warming equipment as well as the rice cultivar.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.562-568
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• 1998

Rice (Dongjin-byeo) added with black rices (Chindo and Suwon-415) was cooked and the changes of texture and color of this cooked rice were investigated by texture analyser and color & color difference meter. The hydration time to come to the equilibrium condition was at least 11 hr in black rices. The optimum ratio of water to cooked rice added with black rice was 1.6 (ratio of water to rice) and the hardness of cooked rice added with 5% Chindo black rice was $5.66\;kg_f$. Regardless of ratio of water to rice, Hunter a value increased as the ratio of black rice addition to rice increased, while L value decreased. The color elution rate of Suwon 415 was 4 times greater than that of Chindo black rice. The pH of the steep water of Suwon 415 at $20^{\circ}C$ during 120 min decreased from pH 6.40 to pH 6.16 as the steeping time increased. The optimum heating time by microwave oven of cooked rice added with black rice was between $90{\sim}120\;sec$ to recover the original texture after cold storage treatment of 7 days.

• Korean journal of applied entomology
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• v.42 no.2
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• pp.145-152
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• 2003

Field application of the entomopathogenic nematode, Steinernema carpncapsae, is limited by its susceptibility to UV irradiation and desiccation especially at leaf spray control. This study was conducted to develop the control technique using alginate biocapsulation of the nematodes against the beet armyworm, Spodoprera exigua and the tobacco cutworm, Sp. litura that are normally infesting hosts above ground level. The alginate capsules including infective juveniles gave significant feeding toxicities to the larvae of the two lepidopteran species. The lethality followed a typical sigmoid dose-mortality pattern with increase of the nematode densities embedded in the capsules. Moisture content in the capsule was critical to the survival of the infective juveniles. More than 80% nematodes could survive above 10% moisture content remained in the capsule. Remaining moisture content within the capsule was dependent on relative humidity, ambient temperature, and capsule size, but not on citric acid reaction time during capsule formation. More than 80% of infective juveniles in the alginate capsules could survive in distilled water at 15$^{\circ}C$ for 60 days. When these nematode capsules containing welsh onion extract as another phagostimulant were applied on the 3rd instar larvae of Sp. exigua infesting peanut plants, they resulted in about 90% control efficacy. These results indicate that the alginate capsulation can be used for leaf-spray agent of the entomopathogenic nematodes as well as for improved storage purpose.