• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.887-893
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• 2010

This study examined the shelf-life and quality characteristics of the wet noodle added with the Acanthopanax senticosus and Eucommia ulmoides extract (AEE). The wet noodle with AEE reduced total microbial counts and TBARS value compared with the control during storage at $4^{\circ}C$ for 21 days. Moisture content of the wet noodle with AEE and control was not different during the early storage period, but after 9 days of storage, that of the control was decreased about 7%, while that of the noodle with AEE was decreased slightly. Lightness of the wet noodle with AEE showed low value in uncooked and cooked noodles compared with the control and decreased during storage. The pH and texture of the wet noodle with AEE and control did not change during storage at $4^{\circ}C$ for 21 days. In sensory evaluation, texture, soup smell and springiness of the wet noodle with AEE were preferred than the control. These results suggested that the AEE can keep the quality characteristics and increase the shelf-life in the wet noodle.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1829-1836
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• 2013

This study is carried out to investigate the physicochemical characteristics, microbial population, and sensory characteristics during fermentation of Korean traditional rice wine with addition of glutinous rice. The fed-batch fermentation of rice was performed by Nuruk and yeast for 10 days at $28^{\circ}C$ in a water bath. The four fermentation batches included 0, 10, 15 and 20% of glutinous rice based on the total rice contents. The growth of total viable cells, lactic acid bacteria (LAB), and yeasts were similar among the four batches during the fermentation period. The population for total viable cells and LAB were increased for the first 3 days, and decreased slowly until 10 days. The number of yeast cells was rapidly decreased after day 6, when the alcohol content reached about 15% for all the fermentation batches. Physicochemical characteristics, such as pH, total acidity, and reducing sugars, were not different with the increase of additional glutinous rice contents. The ethanol production was higher in Korean traditional rice wine from non-glutinous rice (17.1%) than ones from glutinous rice (15.8~16.7%). For the sensory evaluations, Korean traditional rice wine with 15% glutinous rice was highly preferred due to the highest sweetness.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.673-680
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• 2009

This study was conducted to screen for plant food materials that improve human intestinal microflora, especially microorganisms associated with obesity. Among 30 tested plant food materials, the extract of Schizandra chinensis inactivated Eubacterium limosum, Bacteroides fragilis and Clostridium spp. Additionally, S. chinensis extract was also found to have a growth-promoting effect on Bifidobacterium spp.. The antimicrobial activity and antioxidant activity of the water extract did not decrease in respond to heating. Additionally, the water extract of S. chinensis did not show a toxic effect on the growth of Caco-2 cells. In vivo feeding tests were performed to investigate the influence of extract on the intestinal microflora in rats. Although the extract did not reduce obesity induced by a high fat diet, it led to significant increase in the population of Bifidobacterium spp. and a decrease in the population of Clostridium spp. in rats. Taken together, these results indicate that S. chinensis could be useful as a functional food component to control intestinal microbial flora.

• Journal of Food Hygiene and Safety
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• v.29 no.3
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• pp.195-201
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• 2014

This study was conducted to investigate the current status of hygiene performance and food preparation/storage condition in restaurants during the summer season in order to evaluate the sanitary management systems in restaurants against climate change. Total 30 restaurants located in Gyeonggi participated in a survey in which they were asked current hygiene performance, food preparation/storage condition, and purchasing practices for 5 food ingredients. As results, regarding the performance degree of respondents on food hygiene management, the average scores of 9 questions were well over 4 points. However, only 6.83% of the respondents claimed that they use sanitizers (chlorine) to disinfect food ingredients. About food storage condition, a high proportion of respondents said that they store food materials in plastic bags or airtight containers following pretreatment and use refrigerator for the storage of pretreated food materials. However, 5.55% and 14.85% of respondents answered that they store pretreated food materials in the kitchen or inside of dining room, respectively. Respondents (21.50%) answered that they store pretreated food materials for more than 6 hours before cooking. Therefore, food materials need to be disinfected properly with sanitizer to remove microbial contamination and stored at refrigerator using closed bags or containers before cooking in order to prevent foodborne disease in restaurants especially during summer season.

• Korean Journal of Food Science and Technology
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• v.29 no.1
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• pp.57-64
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• 1997

The research was investigated to determine the effect of organic acids or packaging methods (PA) either alone or in combination on the quality of Aster scaber during storages. The Aster scaber was treated with organic acids and PA, and stored at different temperature $(1\;and\;5^{\circ}C)$. Total plate counts, weight loss, color change, and sensory evaluation were evaluated. Both organic acid treatments, PA, and combined treatment had little effect on the inhibition of total plate counts compared to the control (non-treatment). Organic acid treatments showed less weight reduction compared to the control and nitrogen treated package had the least weight reduction, but the combined treatments showed less weight reduction than organic acid treatments or packaging method alone. Organic acid treatments were little different from the control on color change, but nitrogen packages had the least color change, whereas combined treatments were a little reduced, but little different compared to the control or nitrogen packages. The nitrogen packages showed better effects on the sensory evaluation compared to other treatments and the results of sensory evaluation were consistent with that of weight reduction and color change, but not in total counts. All these results showed better effects in $5^{\circ}C$ rather than $1^{\circ}C$.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.23-37
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• 1990

In order to disclose the contamination of the Mushim-Cheon by pollutants in August and September of 1989 and to establish countermeasures, the collected water samples were analyzed to obtain the following results : 1. The water temperature of the period ranged from 25.8 to $30.8^{\circ}C$ acceptable for the growth of microorganisms and algae to allow the self-purification of the stream. 2. The pHs at the sites during the same period ranged from 6.5 to 8.5 which fall within the allowed values for the first grade water supplies except for site 14. 3. At site 18 which is the confluence of the sewer of the excretion disposal facilities and the main stream, the DO was observed to fall down to 0.7 ppm in September. 4. The BOD value reached a maximum of 62.1 ppm at site 18, which far exceeded the limit of 40 ppm, the allowed value for the discharges from the disposal facilities. In addition, the SS values were 200 and 520 ppm in August and September, respectively, which were three to seven times as high as the allowed limit of 70 ppm. 5. The high $NH_3-N$ value of 46.2 ppm at site 18 in September suggested that the water was heavily contaminated with excretions. 6. The BOD load of the sewage from site 12, the Sajik-Dong Sewer, in September was estimated to be about 0.306 ton/day. 7. The contamination of the influents, the family wastewater, and the discharges from the disposal facilities was greater than that of the main stream. 8. In the samples collected from site 12, the Sajik-Dong sewer at an interval of every two hours, a close correlation was observed between the pollutant load and the life cycle of the nearby inhabitants. 9. Compared with the results obtained from the water samples in 1979, it was observed that the water was heavily contaminated at site 12 (the Sajik-Dong Sewer, under the Chung Ju Great Bridge) and site 15 (Under the 2nd Uncheon Bridge) over the last 10 years, with little difference at site 9(Young Un-Dong water supply source).

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.6
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• pp.867-874
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• 2011

This study was performed the effect of Sargassum fulvellum extracts (SFE) on the shelf-life and quality improvement of bread. Bread was added with 0.5, 1 and 2% SFE and stored for 9 days. Total microbial counts of the bread added with 1 and 2% SFE were reduced by 2 log cycles at 9 days, and there were no significant changes in pH value or moisture content compared to the control. In addition, the protection factor of the bread added SFE measured by Rancimat showed a higher level than that of the control. Yellowness increased as bread was added with SFE while lightness and redness decreased. Springiness showed no considerable differences between the control and the group added with SFE. Hardness, shear force, gumminess and chewiness were higher than those of the control. In the sensory evaluation, right after manufacturing, taste, texture, and total preference of the bread containing 0.5 and 1% SFE were preferred compared to the control. These results suggest that the addition of 0.5% and 1% SFE to bread enhance the quality and shelf-life of bread.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.220-226
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• 1998

The effects of metalaxyl(granule), carbofuran(granule) and simazine(water soluble powder) on the soil microflora were conducted at field soil between Iksan and Chonju province. Pesticides were divided into 0.5, 1, 1.5 and 2.0 times of normal of field, respectively. The number of fluorescent Pseudomonas was ranged from $10^3$ to $10^6/g$ in both field soil treated with cabofuran. Pseudomonas concentration of Chonju field soil slowly increased and approached the maximum level at 56 day after treatment(DAT). It showed the higher at 14DAT than other DAT in Iksan field soil treated with metalaxyl or simazine, whereas it increased again at 112 DAT in metalaxyl treatment. Cabofuran treatment of both field soil showed maximum Pseudomonas number at 28 DAT compared to that of other treatments. In Chonju field soil, those Pseudomonads of metalaxyl and simazine treatment increased the highest level at 7 DAT. Simazine treatment decreased it's number from the beginning of experiment. In both soil, metalaxyl treatment decrease the general fungi number at 7 DAT, but increase at 14 and 56 DAT in Iksan field soil. However it increased at 56 DAT in Chonju field soil. Cabofuran treatment of Iksan field soil tended to decrease general fungi number at 28 DAT, but was ranged from 1.0 to $8.6{\times}104/g$ for the rest of experimental period. It started to increase at 56 DAT simazine treatment of Iksan. General bacterial concentration both soil treated with cabofuran was belong to $26.6{\sim}29.6{\times}106$. It was the highest at 56 DAT, but was not significantly different. General actinomyces number was highly increased at 7 and 112 DAT compared to that of other DAT. Pseudomonas putida or P. fluorescens from both field soil was separated and identified 10 to 30 of all 104 Pseudomonas, respectively. All isolated microorganisms showed chemical resistance of 100ppm metalaxyl, cabofuran and simazine treatment.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.206-210
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• 2017

This study was performed to develope mathematical models for predicting growth kinetics of Staphylococcus aureus in the processed meat product, pyeonyuk. Growth patterns of S. aureus in pyeonyuk were determined at the storage temperatures of 4, 10, 20, and $37^{\circ}C$ respectively. The number of S. aureus in pyeonyuk increased at all the storage temperatures. The maximum specific growth rate (${\mu}_{max}$) and lag phase duration (LPD) values were calculated by Baranyi model. The ${\mu}_{max}$ values went up, while the LPD values decreased as the storage temperature increased from $4^{\circ}C$ to $37^{\circ}C$. Square root model and polynomial model were used to develop the secondary models for ${\mu}_{max}$ and LPD, respectively. Root Mean Square Error (RMSE) was used to evaluate the developed model and the fitness was determind to be 0.42. Therefore the developed predictive model was useful to predict the growth of S. aureus in pyeonyuk and it will help to prevent food-born disease by expanding for microbial sanitary management guide.