• Korean Journal of Environmental Biology
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• v.38 no.4
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• pp.733-743
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• 2020

We estimated the carbon storage of coal mines reclaimed using Betula platyphylla (BP), Pinus koraiensis (PK), and Pinus spp. (PS, Pinus densiflora, Pinus rigida, and Pinus thunbergii). The carbon storage of tree biomass (TB), forest floor(FF), mineral soil (MS), and the total forest were quantified. Reclaimed sites were located in Gangwon-do, Gyeongsangbuk-do, and Jeollanam-do; reclamation was conducted at various times in each region. The carbon storage (ton C ha^-1) in FF (BP: 3.31±0.59, PK: 3.60±0.93, PS: 4.65±0.92), MS (BP: 28.62±2.86, PK: 22.26±5.72, PS: 19.95±3.90), and the total forest(BP: 54.81±7.22, PK: 47.29±8.97, PS: 45.50±6.31) were lower than that of natural forests (NF). The carbon storage in TB was lower in BP (22.57±6.18) compared to NF, while those in PK(21.17±8.76) and PS (20.80±6.40) were higher than in NF. While there were no significant differences in the carbon storage of TB, FF, and the total forest among tree species, results from MS showed a significant difference among species. TB and the total forest carbon storages in all sites increased after reclamation. Soil pH and cation exchange capacity values in BP and PS were lower than in NF. Amounts of labile carbon, available phosphate, and microbial biomass carbon in reclaimed sites were less than half of NF. There are a number of methods that could increase the reclamation efficiency. Applications of lime or organic fertilizers, as well as tillage operations, may improve soil properties in reclaimed coal mines. Additionally, pruning and thinning would increase tree growth thereby increasing carbon storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1864-1871
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• 2013

The effect of additives on the quality of low salted doenjang was investigated during storage. Amylase activity gradually decreased during storage and protease activity decreased after four weeks. The number of yeast was lower in the mustard or ethanol added groups without a difference in bacterial count. The L- and b-values decreased gradually during storage with lower total color difference (${\Delta}E$) in garlic added doenjang. Gas production was reduced in the ethanol or mustard added groups. Titratable acidity and acid values were low in the ethanol and ethanol-garlic added ones. A reducing sugar content was higher in the groups with added additives. Ethanol decreased to the largest extent in mustard added doenjang. Amino-type nitrogen decreased in ethanol added doenjang, whereas ammonia-type nitrogen was low in the ethanol or mustard added groups. The taste, flavor, and overall acceptability of doenjang were significantly higher in the ethanol or garlic added groups than in the other groups.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.361-367
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• 2010

Bacterial contamination of cooked rice was analyzed to evaluate the microbial safety. Thirty raw rice samples were collected in Korea and cooked in an electric rice cooker. Mesophilic aerobe, food-poisoning Bacillus cereus group, and their toxin genes were determined on cooked rice. The percentage of total mesophilic aerobe based on 1-3 log CFU/g was 27% among the samples. Bacillus spp. in MYP selective medium was similar to the number of mesophilic aerobe, whileas Bacillus spp. was detected in most samples after enrichment. Thirty-seven isolates from 30 cooked rices were identified as B. thuringiensis, B. cereus, B. valismortis, B. pumilus, B. coagulans, B. licheniformis, Geobacillus stearothermophilus, and Brevibacillus laterosporus. Twenty isolates (54%), more than half of the isolates, were B. thuringiensis while nine (27%) were identified as B. cereus. All B. thuringiensis isolates possessed non-hemolytic toxin genes and interestingly, seven B. cereus among nine isolates possessed emetic toxin genes. More B. thuringiensis was present on the cooked rice than B. cereus and most B. cereus possessed emetic toxin genes rather than diarrheal toxin genes. Therefore, food-borne outbreak due to B.cereus on the cooked rice kept at room temperature might be examples of emetic food-poisoning.

• Korean Journal of Food Science and Technology
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• v.37 no.3
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• pp.449-455
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• 2005

To reduce saft content of kochujang, various combinations of sub-materials such as ethanol mustard and chitosan were added to kochujang, and their effects on microbial characteristics, enzyme activities, and physicochemical characteristics of kochujang were investigated after 12 weeks of fermentation. Activities of ${\beta}$-amylase and pretense were low in ethanol-mustard-chitosan-added kochujang, whereas no significant difference was observed in ${\alpha$-amylase activity among all groups. Number of viable yeast cells decreased remarkably in mustard-added kochujang during late aging period, and anaerobic bacterial counts decreased in sub-material-added groups. Consistency of kochujang increased by addition of sub-materials, and oxidation-reduction potential was low in chitosan-added group. Mustard-chitosan-added kochujang showed lowest increase in total color difference(${\Dalta}E$) and decrease in water activity. PH of kochujang wns highest in mustard-chitosan-added kochujang, resulting in significantly increased titratable acidity. Addition of sub-material increased reducing sugar contents of kochujang, whereas ethanol production was significantly repressed in mustard-chitosan-added kochujang. Amino nitrogen content was Highest in mustard-chitosan-added kochujang during late aging period, whereas ammonia nitrogen content was lower in ethanol-mustard-added kochujang. Results of sensory evaluation indicated ethanol-mustard-added kochujang was more acceptable than other groups in taste and overall acceptability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.705-710
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• 2004

This study was conducted to investigate the difference of antimicrobial activity between $\varepsilon$-polylysine/grapefruit seed extract mixture and $\varepsilon$-polylysine/glyceride mixture against food-borne pathogens. The minimum inhibitory concentration (MIC) of the $\varepsilon$-polylysine/grapefruit seed extract mixture was 100 times lower than that of the $\varepsilon$-polylysine/glyceride mixture. In case of the $\varepsilon$-polylysine/glyceride mixture the MIC of Bacillus cereus (0.1 $\mu$L/mL) and Pseudomonas aeruginosa (0.1 $\mu$L/mL) were lower than that of Escherishia coli (15 $\mu$L/mL). When rices were cooked with the $\varepsilon$-polylysine/glyceride mixture the number of total microbial cell was decreased during storage at 2$0^{\circ}C$ as concentration of the $\varepsilon$-polylysine/glyceride mixture increased. The antimicrobial activity was the highest against Escherishia coli as the concentration of the $\varepsilon$-polylysine/glyceride mixture increased. Sensory terms such as taste, flavor and texture were not significantly different in cooked rices prepared with 0.5% $\varepsilon$-polylysine/glyceride mixture, but there was significantly different in cooked rices prepared with 1% (p＜0.05) in the overall acceptability, indicating that the cooked rice with 0.5% $\varepsilon$-polylysine/glyceride mixture was recommended.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.500-506
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• 2005

This study was carried out to obtain knowledges on the survival of Streptococcus mutans in the yoghurt added with green tea powder. The growth inhibition of green tea powder on the food borne pathogens and oral bacteria was measured by total microbial count, Among the tested food borne pathogens, the growth of Staphylococcus aureus and Salmonella enteritidis were not significantly affected by the addition of green tea powder, but green tea powder showed the growth inhibition effect on Escherichia coli O157:H7. The number of surviving Streptococcus mutans cell was decreased by $0.56\~0.99log$ cycle after 24 hem incubation by the addition of $0.5\~2.5\%$ green tea powder in the medium. And also the viable cell count of surviving Streptococcus mutans cells (initial inoculum $3.4\times10^7CFU/mL$) were decreased to $1.4\times10^4\~7.2\times10^4 CFU/mL$ after 48 hours incubation when $0.5\~2.5\%$ green tea powder were added to the drinkable yoghurt, Growth of Streptococcus mutans was strongly inhibited by the addition and incubation of green tea powder for 48 hum in the yoghurt.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.4
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• pp.615-620
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• 2013

To extend the shelf-life of salted Chinese cabbages, electrolyzed water (EW) was used to wash raw Chinese cabbages before the salting process (to control microbial growth), and different storage temperatures evaluated (0, 4, and $10^{\circ}C$). A tap water washing group (TW) was used for comparison. The initial total bacterial population was 5.36 log CFU/g in the TW treatment and 3.50 log CFU/g in the EW treatment. The EW treatment decreased bacterial numbers by approximately 2 log CFU/g compared to the TW treatment and kept this initial population number for 32 days at $0^{\circ}C$. The salinity had no difference during storage. In general, several factors (pH, reducing sugars, hardness, and transmittance) decreased over time, and decreased slowly with EW treatment and $0^{\circ}C$ storage. Overall, the salted Chinese cabbages with EW treatment showed lower bacterial populations compared to TW treatment, and when stored at $0^{\circ}C$, delayed decreases in quality.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1330-1338
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• 2008

This study was conducted to investigate the effects of Acanthopanax senticosus extract (ASE) as a dietary additive on gut microflora in weaned piglets. A total of sixty pigs were weaned at 21 d of age (BW = $5.64{\pm}0.23kg$) and allocated on the basis of BW and litter to three dietary treatments in a randomized complete block design. The dietary treatments were: control group (basal diet), antibiotics group (basal diet+0.02% colistin), and ASE group (basal diet+0.1% ASE). On d 7, 14 and 28 after consuming the experimental diets, five piglets per group were sacrificed and then the contents from the jejunum, ileum and cecum were collected to determine changes in the microbial community by using a polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) technique and estimating the contents of Lactobacillus and E. coli by in vitro culturing methods. The results showed that the ASE promoted the microflora diversity in the cecum. Enumeration of bacteria in the gut contents showed that the number of Lactobacillus increased (p<0.05), while that of E. coli decreased (p<0.05) when compared with the other 2 groups as the days of age progressed post-weaning. These findings suggested that the ASE, as a substitute for dietary antimicrobial products, could improve the development of the normal gut microflora and suppress bacterial pathogens, and effectively promote a healthy intestinal environment.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.656-660
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• 2008

Fermented soybean foods are an important component of the Korean diet. Eoyukjang is a type of traditional fermented soybean source. Microbial analysis of eoyukjang was conducted during the fermentation period in this study. Microorganisms isolated from eoyukjang were identified by biochemical tests and 16S rDNA sequencing. 17 different microorganisms, including bacteria, yeast, and fungi were detected in eoyukjang during the fermentation period. Even though Aspergillus participated in the early stage of fermentation of eoyukjang, Bacillus species and Saccharomyces cerevisiae were the major microzymes in eoyukjang throughout the maturation period. Eoyukjang is generally consumed after the boiling of the final sample. Therefore, the final sample of eoyukjang was boiled and analyzed. Our results showed that no vegetative microorganisms survived under the boiling conditions for eoyukjang. Fermented soybean products in the domestic market were also assessed for comparison with the results from eoyukjang. The total cell number of kanjang (soy sauce) samples was between 0 to 42 CFU/mL. The isolated microorganisms were identified as Bacillus species. All Bacillus isolates were not found to harbor the three enterotoxin-producing and emetic toxin-producing genes.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.127-134
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• 2018

To prolong the shelf-life of chicken breast meat, samples were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 7~15 ppm for eight days at $4^{\circ}C$. The microbial, physicochemical properties and sensory evaluation of the treated samples were investigated. The total number of bacteria in the control increased during storage and showed 6.78 log CFU/g on the 8th day of storage, but $ClO_2$ gas treatments showed 6.24~6.58 log CFU/g at the same time. The initial pH of chicken breast meat was 6.00 and gradually increased during storage. And $ClO_2$ gas treatments did not show any significant difference from the control during storage period, but maintained a generally lower pH than that of the control. The lightness, redness, and yellowness during storage were not significantly different between the control and the 7~10 ppm $ClO_2$ gas treatments. However, as the storage period was increased, the redness of 15 ppm $ClO_2$ gas treatment was reduced. The cooking loss and shear force were not different between the control and $ClO_2$ gas treatments during the storage period. Volatile basic nitrogen (VBN) increased in the control from the 6th day of storage and 23.80 mg% in the 8th day of storage. However, VBN of $ClO_2$ treatments showed lower than that of the control. In the change of sensory evaluation during storage, 10 ppm $ClO_2$ treatment showed the highest preference in odor, appearance and overall acceptance during storage period.