• Journal of the Korean Society of Food Culture
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• v.14 no.5
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• pp.455-460
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• 1999

In order to establish the processing condition of salt-fermented liquefaction of sardine (Sardinops melanoslicta), effect of temperature, pH value, and concentration of salinity on crude enzyme activity of sardine viscera were investigated. The optimum temperature range of crude enzyme activity in sardine viscera was $45{\sim}50^{\circ}C$ and the optimum pH value of it was 9.8. According to the concentration of salinity increased the crude enzyme activity in sardine viscera decreased. The relationship between concentration of salinity (X) and the crude enzyme activity (Y) in sardine viscera is shown as follows; Y=-0.01363X+0.7676 (r=-0.88). For the purpose of processing conditions of rapid- and low salt-fermented liquefaction of sardine, changes of viable cell count, histamine content, and volatile basic nitrogen (VBN) in the chopped whole sardine with 8% NaCl during preheating process at $40^{\circ},\;45^{\circ}$ and $50^{\circ}C$ for 48 hrs were analyzed. During preheating, initial viable cell counts of chopped whole sardine were $10^{4-7}/g$, but they decreased $10^{1-5}/g$ after 48 hrs. Histamine contents during preheating process at $40^{\circ}\;and\;45^{\circ}C$ were gradually increased, whereas at $50^{\circ}C$ were almost the same level after 48 hrs. VBN contents were continuously increased during preheating, but preheating at $50^{\circ}C$ samples were lower level than that of $40^{\circ}\;and\;45^{\circ}C$ ones. For the purpose to accelerate the fermentation and liquefaction of chopped whole sardine, preheating at optimum temperature of crude enzyme activity for 48 hrs was useful processing method and the contents of viable cell count, histamine, and VBN were safety level for food sanitation.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.209-218
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• 2021

This study was carried out to investigate the effects of Bifidobacteria growth promoter BE0623 and a dietary fiber supplement, which included Bifidobacterium lactis BB12, Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium lactis. In fermented milk containing BE0623, the viable cell count of Bifidobacteria significantly increased by about 45 to 75 times compared to the control, and the titratable acidity increased, whereas the pH decreased. All fractions obtained by isolating BE0623 had Bifidobacteria growth effect. Acacia dietary fiber is a pale yellow powder. It has a viscosity of 60 to 100 cPs and a pH between 4.1 and 5.0. Its general components are less than 10% moisture, more than 90% dietary fiber, and less than 4% ash. The optimal addition ratio of Bifidobacteria growth promoting material was determined to be 0.05%. The general components of the manufactured fermented milk were carbohydrate 17.85%, protein 3.63%, fat 3.00%, and dietary fiber 2.95%. During storage of the fermented milk for 24 days, its titratable acidity, viscosity, and sugar content all met the criteria. In addition, the viable cell counts of Bifidobacteria and lactic acid bacteria in the fermented milk were 1.7 × 10⁸ CFU·mL^-1 and 1.5 × 10⁷ CFU·mL^-1, respectively, and Escherichia coli was negative. There was no significant difference between the control group and the treatment group in the sensory evaluation of sweet, sour, weight, and flavor, and the preference for the treatment group was excellent. The acceptability of the fermented milk of the treated group according to the storage period was excellent in terms of color, flavor, and appearance.

• Culinary science and hospitality research
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• v.18 no.5
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• pp.220-232
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• 2012

The study was carried out to evaluate the storage and quality characteristics of Duteoptteok added with mugwort. The content of moisture and crude fiber in Duteoptteok significantly increased while that of the crude protein and crude ash decreased by adding 10, 20 and 30% of mugwort. As for the color value, the L, a, b value of Duteoptteok decreased as the amount of mugwort increased. Also, the L value decreased by the increase of the storage period. However, the a and b value didn't show any significant difference. For the texture characteristics, as the amount of mugwort increased, the hardness, springiness, cohesiveness, gumminess and chewiness decreased; however, the adhesiveness increased. Moreover, the hardness, adhesiveness, gumminess and chewiness increased according to the changes of the storage period, while the springiness and cohesiveness decreased. According to higher amount of mugwort, the gelatinization degree increased while the retrogradation degree decreased. The viable cell count and yeast and mold count showed a decreasing tendency as the amount of mugwort increased while they increased by increasing the storage period. The results from this study suggests that the quality characteristics of Duteoptteok improved and storage period became longer by adding mugwort.

• Journal of the Korean Society of Food Culture
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• v.30 no.6
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• pp.757-765
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• 2015

The objective of this study was to determine the quality characteristics of fermenting mash and pasteurized ginseng Makgeolli added with different concentrations of ginseng powder. Total aerobic bacteria and lactic acid bacteria counts of mash added with 0, 1, 2, and 4% ginseng powder during 4 days of fermentation significantly increased, whereas yeast count decreased. Viable cell count remarkably decreased after pasteurization. Pasteurized 4% ginseng Makgeolli (4.30) showed a higher pH than 0, 1, and 2 % ginseng Makgeolli (4.09, 4.08, and 4.06, respectively) after 15 days of aging. After aging, amylase activity of pasteurized Makgeolli decreased, and 0% and 1% ginseng Makgeolli (22.35, $21.55^{\circ}Brix$) showed higher Brix content than 4% ginseng Makgeolli ($20.15^{\circ}Brix$). Before aging, alcohol contents of 0, 1, 2, and 4% pasteurized ginseng Makgeolli were 5.80, 5.50, 5.20, and 5.10%, respectively. After 15 days of aging, 0% ginseng Makgeolli (7.00) showed higher alcohol content than 1, 2, and 4% ginseng Makgeolli (5.90, 5.80, and 5.60%, respectively). The results of the sensory evaluation show that 2% ginseng Makgeolli after 3 days of aging at $4^{\circ}C$ had the highest scores for taste (5.19), flavor (5.04), and overall acceptability (5.22) among the samples.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.349-357
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• 2019

The effect of entrapping isothiocyanates extracted from horseradish root by microencapsulation on the shelf life of Myeongran jeotgal was evaluated. The total viable cell count of Myeongran jeotgal reached $10^7CFU/g$ (initial decomposition level) on days 43 and 45 of treatment with 1.0% and 2.0% microcapsules (4.0 mg/mL), respectively, compared with day 21 of storage at $5^{\circ}C$ as the control treatment. The proteolytic bacterial counts of Myeongran jeotgal treated with 1.0% and 2.0% microcapsules were $2.0{\times}10^5$ and $9.5{\times}10^4CFU/g$, respectively, with 2 and 3 log reductions compared with the control count ($1.1{\times}10^7CFU/g$) on day 33 of storage at $5^{\circ}C$. The total volatile basic nitrogen (TVB-N) level reached 30.0 mg% (initial decomposition level) on days 47 and 48 of treatment with 1.0% and 2.0% microcapsules, respectively, compared with day 33 of storage at $5^{\circ}C$ as the control. Based on the sensory evaluation, the freshness of Myeongran jeotgal treated with 1.0% microcapsules was best compared with the other treatments. Based on the total viable cell count, TVB-N and sensory evaluation, the shelf life of Myeongran jeotgal treated with 1.0% microcapsules was extended by 22, 16 and 15 days, respectively, compared with the control at $5^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.3
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• pp.203-208
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• 2024

Fifteen cultured frozen abalone Haliotis discus hannai samples were purchased from supermarkets, traditional markets, online markets, and processing factories throughout Korea for the safety assessment of microbiological and chemical hazards. Sanitary-indicative (total viable bacteria, coliforms, and Escherichia coli) and pathogenic (Staphylococcus aureus, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Clostridium perfringens, and Enterohemorrhagic E. coli) bacterial contamination levels were assessed quantitatively or qualitatively. Additionally, heavy metal content (lead, cadmium, and total mercury) and radioactivity (¹³⁴CS+¹³⁷CS, ¹³¹I) were quantitatively assessed. The total viable bacterial count was 4.3×10² CFU/g, while coliform count was 50 CFU/g. E. coli was not detected in any of the samples (count < 10 CFU/g). All six pathogenic bacteria tested negative qualitatively. The average lead, cadmium, and total mercury contamination levels in the cultured frozen abalone were 0.100±0.057, 0.145±0.061, and 0.015±0.001 mg/kg, respectively. Moreover, none of the samples were radioactive. According to the results of this study, cultured frozen abalones distributed in all types of markets were safe from all microbiological and chemical hazards.

• Journal of Environmental Health Sciences
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• v.12 no.2
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• pp.39-48
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• 1986

This study was carried out to investigate the bacterial contamination of Ice Tea sold on the l street in Seoul area. For this, study 81 samples were collected on the street from July to September, 1985 and were examined on the following items. 1. Degree of bacterial contamination. 2. The relation of the occurrence of fecal coliform and salmonella. 3. The change of bacterial contamination in Ice Tea against temperature. As the results of this study, the following conclusion were obtained. 1. The mean count of total viable bacteria by standard plate count was $6.5{\times}10^3$/ml, the mean count of total coliform and fecal coliform by MPN method were $3.4{\times}10^2$/100ml, 5.5/100ml and those of fecal streptococci was $3.2{\times}10^2$/100ml. 2. The mean count of Staphylococcus aureus was 10.5/ml, the isolated rate of salmonella was 7.41%. 3. In relation to the occurrence of fecal colfform and salmonella, salmonella isolated that for values above $10^2$ fecal coliform 100ml. 4. In the change of bacterial contamination in Ice Tea against temperature, the number of total coliform and fecal coliform increased at $25{\circ}$C, decreased at $4{\circ}$C, but fecal streptococci increased at $25{\circ}$C and $4{\circ}$C.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.687-692
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• 1992

A simple method to determine viable cell numbers of each species in mixed culture was developed. The oxygen uptake rate (OUR) equals to the product of the specific OUR and the size of the microbial population. In a mixed culture, the OUR is a result of the respiration activities of each sub-population. The OUR was determined from the slope of the linear relationship between time and the decrease of dissolved oxygen concentration when aeration was stopped. The specific OUR was calculated from the slope of the viable cell number versus OUR curve. These values for C. lusitaniae at 20 and $30^{\circ}C$ were $1.36{\times}10^{-9}$ and $3.90{\times}10^{-9}$ and those for P tannoPhilus at 20 and $30^{\circ}C$ were $0.59{\times}10^{-9}$ and $1.86{\times}10^{-9}$ [(%/s)/(cells/ml)J. respectively. Using these values, viable cell numbers were calculated after the OURs of mixed culture at two temperatures were measured. A good agreement between the viable cell numbers determined by this method and by plate count was obtained.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.199-203
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• 1993

The bacteriocin produced by Pediococcus acidilactici KFRI 168 exhibited a wide antimicrobial spectrum including many strains of lactic acid bacteria, Listeria monocytogenes, Staphylococcus aureus, and Enterococcus faecium by both disk and deferred assay methods. Inhibition of Lis. monocytogenes and Stph. aureus were observed only from deferred assay. Gram-negative bacteria were not inhibited. Bacteriocin production was observed at 10 h, and was maximized at 16 h in MRS broth incubated at $37^{\circ}C$. In a beaker sausage fermented with P. acidilactici KFRI 168, viable counts of Stph. aureus, Salmonella, Escherichia coli, Clostridium perfringens, and Lis. monocytogenes were reduced by 2.8, 2.3, 2.4, 0.7, and 0.5 log CFU/g, respectively. Inoculated P. acidilactici KFRI 168 maintained its viable count of more than $10^8$ CFU/g during the whole fermentation period, and it took less than 8 h to reduce sausage pH below 5.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.181-192
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• 2005

This study evaluated the effect of factors influencing the initial biofilm formation in drinking water distribution pipe by running experiments using a $2^{4-1}$ fractional factorial experimental design with a replicate. Important variables used for assessing biofilm formation included BDOC(biodegradable dissolved organic carbon), viable heterotrophic bacteria present in drinking water, water temperature, and shear stress at two levels each. Based on the statistical analysis of biofilm levels measured as attached HPC(heterotrophic plate count) and community-level assay, the main factors that have significant effects on biofilm formation were found to be viable heterotrophic bacteria and BDOC. Water temperature only exhibited significant effect on the levels of attached HPC, while shear stress was not a significant factor under given conditions. Moreover, the statistical analysis revealed that interactions between the important variables were not statistically significant at a 0.05 significance level.