• Journal of Food Hygiene and Safety
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• v.3 no.4
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• pp.233-239
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• 1988

Vegetable mixed codiments, commercial products prepared using soybean,paste and natto, respectively as the ingredients, were used ina study to evaluate the efficacy of gamma irradiationas a means of decontamination and the emphasis was placed upon the determination of the effect of irradiation on the microbiological and some physicochemical properties of the samples. The number of microorganisms contaminated ranged from $10^{6}\;to\;10^{7}$ cells per gram in mesophilic total bacteria, which were composed of thermophilts and acid tolerant bacteria by over 90%. They were reduced by 3 to 4 log cycles with irradiation at 10 kGy. Gamma irradiation at 5 kGy could eliminate the microbial populations of yeasts and molds ($10^{2}\;to\;10^{3}$ cells per gram) and coliforms ($10^{6}\;to\;10^{6}$ cells per gram of natto condiments). However, total destruction of microorganisms in soybean-paste and natto condiments was shown to be possible at a dose-range more than 10 kGy. Irradiationup to 10 kGy was not detrimental to the physicochemical properties of the sample, such as pH. amino nitrogen, rancidity and color, even though some change was brought about in the content of sulfur-containing amino acids.

• Journal of Radiation Industry
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• v.7 no.1
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• pp.29-35
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• 2013

Microbiological populations and the sterility of commercial powdered products treated with gamma irradiation at 0~10 kGy were investigated before using them as ingredients for a non-cooked Saengsik product. We evaluated a total of 14 powdered products: 8 powdered cereals, 3 powdered tubers, and 3 powdered leafy vegetables. The total numbers of bacterial populations in non-irradiated powdered cereals, tubers, and leafy vegetables were 2.7~6.9, 5.6~6.0, and $5.3{\sim}6.8\;log\; CFU{\cdot}g^{-1}$, respectively. Moreover, coliform bacteria were not indicated in adlay, millet, germinated brown rice, soybean, and mulberry leaves powder within detection limit ($2.0\;log\; CFU{\cdot}g^{-1}$). The number of Bacillus cereus exceeded $3.0\;log\; CFU{\cdot}g^{-1}$ (the maximum limit for Saengsik products) in all samples, excluding perilla seeds, buckwheat, barley, oat, potato, and Jerusalem artichoke powder. However, a dose of 6 kGy of gamma irradiation reduced the microbiological populations in all samples, and all the powdered products met the microbial requirements for Saengsik products. Futhermore, it was confirmed that all microorganisms in the 9 powdered products, except fermented brown rice, sweet potatoes, and 3 leafy vegetables, were sterilized by 10 kGy of gamma irradiation.

• Food Science and Preservation
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• v.12 no.4
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• pp.395-401
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• 2005

This study was carried out to investigate the changes in the fermentation characteristics of Kimchi prepared with various salts (Korean solar salt, Chinese solar salt, washed and dehydrated salt, purified salt and a processed salt). Acidity appeared to increase most rapidly in Kimchi prepared with Korean solar salt and reached higher level. Total microbial count slowly increased at the beginning of fermentation and reached maximum on 6 days, then decreased slowly. The number of lactic acid bacteria was rapidly increased up to $4{\sim}6$ days, and thereafter decreased slowly. In conclusion, any significant differences in fermentation characteristics analyzed was not observed in Kimchi prepared with various salts except acidity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.53-62
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• 2015

To elucidate the microbial consortia responsible for the anaerobic methane oxidation in the methane hydrate bearing sediments, we compared the geochemical constituents of the sediment, the rate of sulfate reduction, and microbial biomass and diversity using an analysis of functional genes associated with the anaerobic methane oxidation and sulfate reduction between chimney site (UBGH2-3) on the continental slope and non-chimney site (UBGH2-10) on the basin of the Ulleung Basin. From the vertical profiles of geochemical constituents, sulfate and methane transition zone (SMTZ) was clearly defined between 0.5 and 1.5 mbsf (meters below seafloor) in the UBGH2-3, and between 6 and 7 mbsf at the UBGH2-10. At the UBGH2-3, the sulfate reduction rate (SRR) in the SMTZ exhibited was appeared to be $1.82nmol\;cm^{-3}d^{-1}$ at the depth of 1.15 mbsf. The SRR in the UBHG2-10 showed a highest value ($4.29nmol\;cm^{-3}d^{-1}$) at the SMTZ. The 16S rRNA gene copy numbers of total Prokaryotes, mcrA, (methyl coenzyme M reductase subunit A), and dsrA (dissimilatory sulfite reductase subunit A) showed the peaks in the SMTZ at both sites, but the maximum mcrA gene copy number of the UBGH2-10 appeared below the SMTZ (9.8 mbsf). ANME-1 was a predominant ANME (Anaerobic MEthanotroph) group in both SMTZs of the UBGH2-3 and -10. However, The sequences of ANME-2 were detected only at 2.2 mbsf of the UBGH2-3 where high methane flux was observed because of massive amount of gas hydrate at shallow depth. And Desulfosarcina-Desulfococcus (DSS) that is associated with ANME-2 was detected in 2.2 mbsf of the UBHG2-3. Overall results demonstrate that ANME-1 and ANME-2 are considered as significant archaeal groups related to methane cycle in the subsurface sediment of the East Sea, and ANME-2/DSS consortia might be more responsible for methane oxidation in the methane seeping region than in non-seeping region.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• Food Science of Animal Resources
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• v.26 no.2
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• pp.166-174
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• 2006

To determine the proper processing and storage conditions, physico-chemical, microbial and sensory properties of venison jerky under different dry times were measured during storage at $30^{\circ}C$ for 28 days. Samples were dried for 3 hr (T1), 4 hr (T2) and 5 hr (T3) at $75^{\circ}C$ in the smoke chamber, respectively. The pH of T1 was slightly lower than those of T2 and T3 as storage time increased. As dry and storage time increased, TBARS of T2 and T3 were significantly higher (p<0.05) than that of T1. In meat color, $L^*$ values of T3 showed slightly higher than those of T1 and T2, while at values were not clearly tendency by the passage of storage time. $b^*$ values of T2 and T3 were higher than that of T1. The water activity were significantly lower (p<0.05) in ,the order of T3$log_{10}$ CFU/g until 28 days and its number were accepted by sensory evaluation. In conclusions, T2 and T3 showed slightly high overall acceptability and lipid oxidative stability compared to T1 conditions. These results indicated that longer dry time ($4{\sim}5 hr$) of venison jerky would be better characteristics as compared to shorter dry time (3 hr) with increased storage time at $30^{\circ}C$.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.390-399
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• 2016

Purpose: The objective of this study was to examine the effect of plant scale and cooking conditions on the quality characteristics of sausages during refrigerated storage. Methods: Sausages used in this study were classified into two groups: those submitted to $1^{st}$ cooked treatments and those submitted to $2^{nd}$ cooked treatments. The pH, volatile basic nitrogen (VBN), gas production ratio, and microorganisms were measured in triplicate. Results: The change of quality in the products was assessed every 7 days by measuring pH, VBN levels, total microbes, coliform bacteria, Escherichia coli, and pathogenic bacteria in the products. Pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, and E. coli were not detected in the sausages with $1^{st}$ cooked treatments. The results showed that the pH of the sausages decline as storage time increased. The pH value of the sausages with $2^{nd}$ cooked treatments changed gradually. VBN levels were generally lower in products with $2^{nd}$ cooked treatments than in those with $1^{st}$ cooked treatments, but they varied with the type of products. On the $35^{th}$ day, the number of total microbes ranged between 6.13-7.12 log CFU/g in products with $1^{st}$ cooked treatments and 3.44-6.92 log CFU/g in products with $2^{nd}$ cooked treatments, showing fewer bacteria in the latter products. Conclusions: $1^{st}$ cooked treatments were effective in microbial control, but $2^{nd}$ cooked treatments could prolong the shelf life of the sausages, indicating a need for differential management of each product.

• Food Science and Preservation
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• v.24 no.1
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• pp.36-43
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• 2017

The aim of this study was to provide the quality index of salted Korean cabbage in a short-term distribution system. Salted Korean cabbages were packaged with or without 2% salt water, and then distributed in a conventional system (CVS) and a cold-chain system (CCS) for 6 h. The material temperature of samples with and without salt water gradually increased to $19.57^{\circ}C$ and $19.43^{\circ}C$ in a CVS, respectively and to $10.73^{\circ}C$ and $12.90^{\circ}C$ in a CCS, respectively. Salinity of the materials in a CCS did not change, whereas salinities of the materials in a CVS were 1.2 and 1.7 fold higher, respectively. Also, a slight increase in acidity was observed in both packaging materials in a CCS. In the case of a CVS, total aerobic bacteria and lactic acid bacteria increased to 7.62 log CFU/g and 6.77 log CFU/g in the materials with salt water, respectively, whereas the number of total aerobic bacteria and lactic acid bacteria ranged between 5.62-5.85 log CFU/g and 4.33-4.83 log CFU/g in the materials without salt water, respectively. However, significant microbial changes were not observed in a CCS as distribution time increased. CCS with salt water packaging was effective in achieving microbial control and maintaining physicochemical quality. Salinity, aerobic bacteria, and lactic acid bacteria can be useful as quality indices for a CVS, and acidity can be useful as quality index for a CCS.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.67-78
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• 2017

The purpose of this study was to investigate the effect of humic acid on the germination, the growth and the yield of hot pepper when treated with organic hot pepper seedlings and growing season. The germination rate of 0.05% and 0.1% humic acid was higher than that of untreated, but the germination rates of 0.4% and 1.0% humic acid were 90.0% and 86.7%, respectively, compared with the control treatment (96.7%). At 30 days after transplanting, hot pepper treated with low (0.05%) or high (1.0%) concentration of humic acid decreased the growth of hot pepper seedlings, whereas 0.2% humic acid treatment significantly increased a average height (97.6 cm), leaf number (84.7) and fresh weight ($128.1g\;plant^{-1}$) of hot pepper. After 60 days of treatment with humic acid, the height of hot pepper was significantly longer in 0.2% humic acid. The mean green fruit number of 0.2%, 0.1% and 0.05% humic acid were not significantly different among the treatments, but the mean green pepper number of 0.4% and 1.0% humic acid treatments were the higher with 35.2% and 29.1%, respectively than other treatments. However, the fresh weight of green pepper was found to be $111.5g\;plant^{-1}$ more heavier than the untreated in 0.2% humic acid. The total ($5.8kg\;plant^{-1}$) and average ($1.4kg\;plant^{-1}$) fresh weight of pepper were higher than that of untreated control, except for the 1.0% humic acid treatment after 60 days of soil irrigation. The total weight of hot pepper treated with 0.2% and 0.1% humic acid treatment was $9.3kg\;plant^{-1}$ and $8.6kg\;plant^{-1}$, respectively, which were heavier than the other treatments. The effect of humic acid concentrations on soil microbial populations, pH and EC was investigated. The soil bacterial population density of 0.2% humic acid treatment was 3.5 times higher than that of untreated control soil. As the concentration of humic acid increased from 0.05% to 1.0%, pH and EC of hot pepper grown soil also increased.

• 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.