• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.1
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• pp.100-107
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• 2017

This study was conducted to evaluate the quality characteristics of got mul-kimchi during storage by type of kimchi container using a plastic ark shell. The pH level, acidity, hardness, color, sensory evaluation, and microbiological activity were performed. Kimchi containers were prepared with 0%, 2%, and 3% plastic ark shell. The pH level of 2% container samples showed no significant difference compared with that of the control, whereas pH levels of 3% container samples were significantly (P<0.05) higher than those of the control and 2% sample. Acidity was not different among treatments up to 4 weeks, whereas acidity of 3% container samples was significantly (P<0.05) lower than those of the control and 2% samples after 8 weeks. Hardness significantly decreased (P<0.05) upon 0, 2, and 3% treatments with increasing storage time, but there was no significant difference among the treatments. Hunter color L values increased in the order of 0, 3, and 2% with increasing storage time. In sensory evaluation of crunchiness, 3% container samples had significantly (P<0.05) higher crunchiness than the control. Total viable cells in the 3% container with got mul-kimchi were significantly (P<0.05) lower than those of other samples at 12 and 16 weeks of fermentation. Numbers of lactic acid bacteria in the 2% and 3% container samples were significantly (P<0.05) lower than those of the control samples after 16 weeks of fermentation. These results show that the plastic ark shell kimchi container extended storage compared with the control.

• Journal of Food Hygiene and Safety
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• v.13 no.4
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• pp.319-331
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• 1998

The purposes of this study were to develop Hazard Analysis Critical Control Point plan applicable to cook/chilled Pork Bulkogi (broiled sliced pork with sauces) in school foodservice operations and to establish reasonable shelf-life limits by assessing food quality during chilled storage period of 5 days. During the product flow, time-temperature profile was recorded and microbiological analyses including mesophilic and psychrotrophic total plate counts, coliform, and fecal coliform and qualitative analyses of Salmonella and Listeria monocytogenes were done. Chemical analyses (pH, acid value, total volatile basic nitrogen), sensory evaluation, and quantitative analysis of thiamin were conducted for 5 days of chilled storage. The number of mesophiles in raw pork ($4.26{\pm}0.11\;Log\;CFU/g$), seasoning mixture ($5.97{\pm}O.04\;Log\;CFU/g$) and marinated pork ($5.56{\pm}0.21\;Log\;CFU/g$) were below the microbial standards for "requires further cooking" food items. Listeria monocytogenes was detected in seasoning mixture. After heating, the number of mesophiles ($5.17{\pm}0.04\;Log\;CFU/g$) were slightly reduced but it did not meet the microbial guidelines of $5\;Log\;CFU/g$ for "ready-to-eat" foods. No other microbes including pathogens were detected. By reheating the menu item after chilled storage, the number of mesophiles were reduced in every phase of 1st day ($4.62{\pm}0.22\;Log\;CFU/g$), 3rd day ($4.55{\pm}0.20\;Log\;CFU/g$) and 5th day ($4.25{\pm}0.16\;Log\;CFU/g$) of chilled storage, and the number of microbes was below the standard limits for "ready-to-eat" foods. At the fifth day of chilled storage, pH (p<0.05), acid value (p<0.01) and TVBN (p<0.05) showed significant increases. Sensory evaluation results did not show any significant change for 5 days of chilled storage. Thiamin content showed a decrease for 5 days of chilled storage. Consequently, the ideal shelflife recommended for Pork Bulkogi was within 3 days of chilled storage. CCPs for Pork Bulkogi were purchasing and receiving of raw meat and some seasoning ingredients, heating, chilling, chilled storage, reheating, and distribution.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.494-501
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• 2010

The purpose of this study was to examine the presence of Bacillus cereus, aerobic bacteria and coliforms in the raw material of infant formulas and investigate the manufacturing process in terms of microbial safety. Among ten kinds of raw infant formula material samples (n=20), Bacillus cereus appeared in two (n=4). Aerobic bacteria were not detected in raw infant formula material or maximum 4.15 log CFU/g. Eleven species of aerobic bacteria were isolated and 76% of them were Sphingomonas paucimobilis, Pseudomonas fluorescens, Rhizobium radiobactor, or Stenotrophomonas maltophilia. A Pearson's correlation analysis revealed that the most influential factors for detecting Bacillus cereus were aerobic bacteria and coliforms. In other words, when the measured values of aerobic bacteria and coliforms were higher, the possibility that Bacillus cereus would appear increased. In a regression model to predict Bacillus cereus, the rate of appearance was correlated with aerobic bacteria and coliforms, and its contribution rate for effectiveness was 86%. Improving microbial quality control by pasteurization, spray dry, popping and extrusion resulted in a decrease in the numbers of Bacillus cereus, aerobic bacteria and coliforms in the raw materials. The results suggest that a hazard analysis and critical control point system might be effective for reducing microbiological contamination.

• Food Science and Preservation
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• v.24 no.2
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• pp.168-180
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• 2017

This study was performed to determine the rapid thawing method for reducing the thawing time of frozen pork loins and to examine the effects of supercooling on the microbiological, physicochemical, and sensory qualities of fresh and frozen-thawed pork during storage at -1.5, 4, and $15^{\circ}C$. Forced-air thawing at $4^{\circ}C$ was the most time-consuming process, whereas radio frequency thawing time was the shortest by dielectric heating. The supercooling storage temperature was chosen to be $-1.5^{\circ}C$ because microstructural damages were not observed in the pork sample after cooling at $-1.5^{\circ}C$ for 24 h. Fresh or frozen-thawed pork loins stored at $-1.5^{\circ}C$ had lower drip loss and total volatile base nitrogen, thiobarbituric acid-reactive substance, and Hunter b* levels than loins stored at 4 and $15^{\circ}C$. In addition, the least degree of increase in preexisting microorganisms counts of the fresh or frozen-thawed pork loin samples was obtained during supercooled storage at $-1.5^{\circ}C$. Sensory quality results of fresh and frozen-thawed pork loin samples stored at $-1.5^{\circ}C$ showed higher scores than the samples stored at 4 and $15^{\circ}C$. These data indicate that supercooling at $-1.5^{\circ}C$ in the meat processing industry would be effective for maintaining the quality of pork meats without ice crystal nucleation and formation.

• Food Science and Preservation
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• v.10 no.2
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• pp.154-157
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• 2003

To examine the quality changes of three typical fishes under usual storage conditions during marketing, we determined the total bacterial counts and pH values during storage of mackerel, croaker, and saury. Mackerels were stored at 0$^{\circ}C$ and on ice at 19$^{\circ}C$, which is the usual storage condition in a local market and croakers and saury were stored at 0$^{\circ}C$ and 4$^{\circ}C$. Total bacterial counts of mackerel, croaker, and saury were 3,2${\times}$10$^3$, 2.9${\times}$10$^3$, and 2.8 x 10$^4$CFU/g at the time of storage respectively. Total bacterial counts of mackerel stored on ice at 19$^{\circ}C$ increased during storage and reached to 8.4 x 10$\^$6/ CFU/g at day 6, while those stored at 0$^{\circ}C$ decreased up to 2 days of storage and increased to 5.6 ${\times}$ 10$^4$CFU/g. For croaker and saury, total bacterial counts at 0$^{\circ}C$ were 2.5 ${\times}$ 10$\^$5/ and 2.1 x 10$\^$5/ CFU/g at day 6, respectively, while those stored at 4$^{\circ}C$ had 3.6 x 10$\^$6/ and 2.6 ${\times}$ 10$\^$5/ CFU/g. the pH value or mackerel was 5.56 at the time or storage, yet it increased to 6.04. The pH changes of croaker and saury had a similar pattern with that of mackerel, which increased with time of storage. These results suggest that storage of fishes at 0$^{\circ}C$ should be better than those at 4$^{\circ}C$ or on ice at 19$^{\circ}C$ in terms of microbial safety as well as quality and shelf-life of fishes.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.477-484
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• 2017

This study was conducted to investigate the content of sulfur dioxide, carotenoids and the degree of contamination of Bacillus cereus in 33 kinds of dried sweet potato from domestic mainly dried agricultural products in Korea. According to the characteristics of dried sweet potato samples, it was classified into four clusters and as a result of analyzing the contents of sulfur dioxide, carotenoids and the degree of contamination B. cereus was no significant difference among the clusters. The detection ranges of residual sulfur dioxide from 33 dried sweet potatoes ranged from 0.38 to 28.16 mg/kg, three cases (9.09%) were detected at the reference level of 10 mg/kg or more. But no samples exceeding 30 mg/kg, the tolerance level of sulfur dioxide in dried sweet potatoes were detected. Since dried sweet potato does not have a standard for carotenoids, when comparing the national and international standards of carotenoids, the range of detection of carotenoids in dried sweet potato was $46{\sim}2,663{\mu}g$/100 g, which was within the reference range of $0{\sim}9,826{\mu}g$/100 g. In principle colonies suspected to be B. cereus in dried sweet potato were not detected. In 7 cases (21.21%), there were detected in the range of 0.05~1.59 log CFU/g but not more than 3 log CFU/g as the reference value. The results of this study are expected to be used as basic data to establish quality standard for dried sweet potatoes. In order to control the quality of dried sweet potatoes in domestic market, raw materials, drying method and packaging after distribution, it is necessary to maintain and maintain the process steadily.

• Korean Journal of Microbiology
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• v.54 no.4
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• pp.369-378
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• 2018

This study was conducted to evaluate effects of dietary microbial probiotics on the growth and disease resistance of olive flounder (Paralichthys olivaceus) in a recirculating aquaculture system (RAS), and the effects of the probiotic bioaugmentation on the microbial community structure and water quality. For the analysis, 80 juvenile fish (average weight, $25.7{\pm}7.6g$; average length, $15.2{\pm}1.7cm$) were fed a basal diet containing a commercial microbial product CES-AQ1 (CES; $1{\times}10^9\;CFU/kg$ diet) in an RAS for 8 weeks. Weight gain, the specific growth rate, feed efficiency, and protein efficiency ratio of the fish fed the CES diet in the RAS were 1.5~2.5 times higher than those of fish fed the basal diet alone, or the basal diet containing oxytetracycline (OTC), yeast plus bacterium, or Bacillus subtilis in a still water system. There was no significant difference in the pathogen challenge test between fish fed the OTC diet and fish fed the CES diet in the RAS, suggesting the CES-AQ1 probiotic used in the RAS as a potential replacement for antibiotics. The RAS biofilter maintained the highest microbial diversity and appeared to harbor microbial communities with ammonium oxidation, denitrification, and fish pathogen suppression functions. Ammonia, which is hazardous to fish, was significantly decreased to < 0.5 mg/L in 19 days, indicating the effectiveness of probiotic supplementation to maintain good water quality in RAS. These results suggest that the intestinal microbial communities of fish are stabilized by a probiotic-containing diet (CES) and that bioaugmentation with probiotics may be an eco-friendly and economical supplement for aquaculture of olive flounder, promoting both good water quality and fish health in an RAS.

• Korean Journal of Poultry Science
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• v.45 no.1
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• pp.29-39
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• 2018

The goal of the present work was to determine the optimal addition amounts of liquid smoke and curing mixture to develop Chuncheon Dakgalbi with improved preference and shelf-life. In the first experiment, Chuncheon Dakgalbi was prepared with different amounts of liquid smoke. In the second experiment Chuncheon Dakgalbi was prepared with various amounts of curing mixture and 0.1% (w/w) liquid smoke. Different amounts of liquid smoke resulted in different aroma patterns, which were observed using an electronic nose, and Dakgalbi with 0.1% (w/w) liquid smoke had the highest score in overall acceptability. The addition of liquid smoke and curing mixture inhibited the growth of bacteria, slowed down the decline in pH, and delayed increased in volatile basic nitrogen contents and lipid oxidation. However, no clear effects were observed on instrumental color. From a consumer preference test, the highest preference score was achieved by added 0.2% (w/w) curing mixture. Liquid smoke and curing mixture extended shelf-life and improved preference of Chuncheon Dakgalbi. Considering the physicochemical, microbiological and consumer preference, it was recommended to add 0.1% (w/w) liquid smoke and 0.2% (w/w) curing mixture to Chuncheon Dakgalbi to enhance shelf-life and preference.

• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.350-358
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• 2015

This study was designed to evaluate the sanitary characteristics of sea water in a part of the south coast, Korea and to check the seawater which is in compliance with the recommended bacteriological criteria for shellfish cultivation. The samples of sea water were collected at 14 sampling stations established in the survey area between March 2014 and October 2014. Food poisoning caused by seafood consumption is often associated with pathogenic microorganisms originated from fecal contamination. Therefore, fecal coliform is very important criteria for evaluating the safety of fisheries in coastal areas. The range of geometric mean (GM) and the estimated 90th percentile values of total coliform were 4.1~83.1 MPN/100 mL, and 11.7~834.1 MPN/100 mL, respectively. The GM and the estimated 90th percentile values of fecal coliform were 2.5~22.7 MPN/100 mL and 2.5~170.0 MPN/100 mL, respectively. Therefore, the bacteriological safety of seawater at this shellfish-growing area met with the Korean Shellfish Sanitation Program (KSSP) criteria for a growing area. However, the values are seasonally exceed the KSSP criteria, suggesting that the monitoring and evaluation of seawater quality is very important in shellfish-growing area.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.312-318
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• 1999

These experiments were conducted to determine the effects of soils treated with different soil management, methods, fertilizers and crops on soil microflora and its number for constructing the environmentally sound agriculture modeling of the upland soils. These experiments show that physico-chemical soil characteristics was different in upland soils treated with different soil managements and fertilizers applied. Also soil microflora and its number were effected from crops cultivated with different soil managements in these experiments. The number of Erwinia sp. in chinese cabbage cultivated field on Daekwanryung especially was apparently increased in soil cultivated with potato relative to corn. It was appeared that the number of Fusarium sp. in soil was more effected from kind of fertilizer applied than crops cultivated.