• Korean journal of food and cookery science
• /
• v.13 no.5
• /
• pp.592-601
• /
• 1997

The purposes of this study were to develop Hazard Analysis Critical Control Point-based standardized recipe applicable to cook/chilled soy sauceglazed mackerel and to evaluate the qualities related to the product flow of this item. After conducting experimental cooking, preliminary test, and analysis of recipes, critical control points were identified, control methods were determined, and HACCP-based recipe was standardized. At each critical control point, time-temperature profile was recorded and microbiological analysis (total aerobic plate counts, psychrotrophic plate count, coliform, and fecal coliform count), chemical analysis (pH, acid value and volatile based nitrogen (VBN)) and sensory evaluation of the item were done. Time-temperature data showed that the time the menu item had passed through temperature danger zone (5∼60$^{\circ}C$) during all phases was 60 min. At rapid cooling, but after cooling at room temperature, the temperature of this menu item did not drop below the ambient temperature. The results of microbiological test were negative throughout all phases following cooking and the results of chemical analysis did not change significantly in terms of storage periods except for VBN which increased on 7th day significantly(p<0.05). After steam/convection oven reheating and microwave oven reheating, the sensory score of the only appearance decreased significantly related to the storage time of overall quality profiles. But significant differences were not detected according to two reheating methods. In conclusion, this HACCP-based recipe was considered as an effective tool for assuring microbial as well as sensory quality of this cook/chilled item.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.642-647
• /
• 2008

This study investigated the microbiological and sensory characteristics of Kongnamul muchim stored with gamma-irradiated red pepper powder at $4^{\circ}C$. Total aerobic microbes in raw Kongnamul muchim were 5.72 log CFU/g in the red pepper powder and 2.40 log CFU/g in the garlic used during storage, but were not detected n other raw materials. Coliform bacteria and fungi were found, at 3.11 and 3.48 log CFU/g respectively, only n the red pepper powder. Microorganisms in Kongnamul muchim stored with gamma-irradiated (10 kGy) red pepper owder were not detected over 3 days of storage at $4^{\circ}C$. The pH, Hunter's color value, and sensory characteristics id not change significantly on storage. These results suggest that the addition of gamma-irradiated (less than 10 Gy) red pepper powder could improve the microbiological safety of Kongnamul muchim without changing desirable ensory characteristics.

• Journal of Food Hygiene and Safety
• /
• v.10 no.2
• /
• pp.111-131
• /
• 1995

Quality changes of sausages in refrierated storage for 60 days were investigated. Nine types of sausages produced in Korea were stored at 4$^{\circ}C$(3~5$^{\circ}C$), and then chemical, microbiological, and sensory characteristics were evaluated on every 10 days. The proximate analysis showed considerable variation in fat (23.97%, 17.10~30.20%) with less variation in moisture (51.96%, 48.10~56.30%) and protein (12.96%, 11.40~13.95%), pH value decreased over time averaging from 6.31 to 6.22 with no significant difference. Water activity was consistent over refrigerated storage averaging 0.95. Volatile basic nitrogen (VBN) values were still within 20 mg% though VBN for all types significantly increased over time (p<0.05). Thiobarbituric acid (TBA) values were well below 1.0 though TBA showed significant differences among storage periods (p<0.05). Standard plate counts (SPCs) significantly increased during storage (p<0.05) while coliform group was not counted in all cases. SPCs reached 104 CFU/g in two types after 50 days' storage and were below 105 CFU/g in all types after 60 days' storage. Instrumental texture analysis showed that springiness, adhesiveness, and hardness signficantly decreased over time (p<0.05) while no change was observed in external color. significantly decreased over time the 60-day storage period (p<0.05) while cohesiveness, chewiness and gumminess did not change. Lightness, redness and yellowness of the internal Hunter color significantly decreased over time (p<0.05) while no change was observed in external color. Sensory profile showed that flavor, taste, texture and overall acceptable after 60 days' storage at 4$^{\circ}C$. However, the shelf-life of the samples should be decided in the consideration of the growth rate other spoilage flora coupled with the bacterial growth after 50 days' storage.

• Korean Journal of Microbiology
• /
• v.21 no.1
• /
• pp.15-26
• /
• 1983

Commercial deerhorns were extracted in boiling water, the deerhorn extracts were per os introduced into rabbits, and then the effects of the extracts on the antibody productions aginst Escherichia coli antigens were investigated for 4 weeks. The experimental rabbits were divided into 4 groups ; control, only deerhorn, only antigen, and antigen plus deerhorn treated groups. The effects of the treatments were measured by counting the number of blood cells, weighing, and immunoelectrophoresis. The rabbits' body weights gained up to 185% in the deerhorn group, and the other groups gained nearly 120%. The numbers of red blood cells in the antigen plus deerhorn group increased somewhat. However, the numbers of leucocytes gradually increased after one week in the antigen group, and at 4 weeks increased up to 290%. In the antigen plus deerhorn group the numbers of leucocytes increased suddenly up to 189% at one week, but after one week the numbers recovered to normal state. Strangely in the deerhorn group the numbers decreased up to 40%. The amounts of serum globulin increased in the control after one week, but maintained about 130%. In the deerhorn group the amounts increased like the control, but after 4 weeks increased up to 175%. In the antigen group the amounts were not changed until 2 weeks, but after 3 weeks abruptly increased over 175%. In the deerhorn plus antigen group the amounts increased gradually up to 262% until 3 weeks, after 3 and 4 weeks the amounts did not increase. The amounts of serum .gamma.-globulin decreased in the control group, and in the deerhorn group and antigen group the amounts did not change until 2 weeks, but after 3 weeks abruptly increased over 175%. In the deerhorn plus antigen group the amounts increased gradually up to 262% until 3 weeks, after 3 and 4 weeks the amounts did not increase. The amounts of serum ${\gamma}-globulin$ decreased in the control group, and in the deerhorn group and antigen group the amounts did not change until 3 weeks, but after 4 week the amounts slightly increased up to 110%. However, the amounts in the deerhorn plus antigen group did not change until 2 weeks, but after 2 weeks abruptly increased up to 174%. The recognized immunoglobulins were IgG and IgM, and the enhanced immunoglobulin was IgG.

• Journal of Microbiology
• /
• v.38 no.4
• /
• pp.265-269
• /
• 2000

Iron increased the susceptibilities of clinical isolates Pseudomonas aeruginosa to quinolones. In the presence of iron, increased susceptibilities to ofloxacin were observed in twenty-six out of thirty isolates and with no change in four isolates. In the case of norfloxacin, iran increased susceptibilities of twelve isolates but did not render any change in eighteen isolates. In the case of ciprofloxacin, iron decreased the MICs (Minimal Inhibitory Concentration) of twenty isolates, increased the MIC of one isolate, and did net change the MICs of nine isolates. To find out how iron increased susceptibility to ofloxacin, bacterial cells were grown in Muller Hinton (MH) media and succinate minimal media (SMM) to induce iran acquisition systems and the intracellular ofloxacin concentrations were assayed in the presence of iron. The addition of iron to the media decreased the MICs of cells whether they were grown in MH or SMM. Siderophores, carbonyl cyanide m-chlorophenylhydrazone (an inhibiter of proton motive force), and ouabain (an inhibitor of ATPase) did not decrease the effect of iron. Results suggested that the increase in the intracellular ofloxacin concentration by iron is accomplished not by decreasing the efflux but by increasing the of ofloxacin permeability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.7
• /
• pp.964-969
• /
• 2009

To improve hygienic quality of vegetable fresh juice containing non-thermal process materials, an irradiation technology ($0{\sim}5\;kGy$) was applied and microbiological and physicochemical changes were evaluated during storage. The initial number of total aerobic bacteria of vegetable fresh juice containing non-thermal process materials was $4.8{\times}10^3\;CFU/mL$ and the number was increased during storage. At day 7, the number reached $3.0{\times}10^5\;CFU/mL$. However, the samples gamma-irradiated at $1{\sim}5\;kGy$ were $1.2{\times}10^2{\sim}1.0{\times}10^3\;CFU/mL$, which was lower than that of control and higher than 3 kGy irradiation, showing more than a decimal reduction. The lightness and yellowness of irradiated sample was higher than control but no difference was found among storage days; whereas, redness was decreased by gamma irradiation with no difference found among storage days. Ascorbic acid and carotenoid contents were decreased by irradiation treatment and increase of storage days. There were no changes in flavonoid contents; however, the content of polyphenols was increased by irradiation of sample.

• Journal of Microbiology and Biotechnology
• /
• v.28 no.1
• /
• pp.105-108
• /
• 2018

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

• Korean Journal of Microbiology
• /
• v.35 no.3
• /
• pp.242-247
• /
• 1999

This sludy was conducted to investigate the change of bacterial co~munities with season and depth in Lake Soyang. Korea, using fluorescence in situ hybridization (FISH). The oligonucleotide probes used in this study were EUB338, ALF I b. GAM42a, and CF, The percentage of h e Proleobacteria a $\alpha$-group ranged from 0.70 to 33% the $\beta$-group from 1.0 to 26% they -group from 2.4 Lo 37% and Cytophagn and Flavobactefin groups from 4.7 to 24% duing the study period (April Lo November, 1998). They $\gamma$-group was dominant in spring when Asterionella was dominant. and a $\alpha$-group was dominant in summer when the organic content was low and Dinobryon was dominant. However, a specific group was not dominant in ？dl when cyanobacteria group was dominant and the ratio of eubacleria to total bacteria was very low. Therefore, the bacterial communities in Lake Soyang changed with season and depth, which seems to be associated with the telnporal succession of phytoplanlaons.

• Korean Journal of Microbiology
• /
• v.32 no.2
• /
• pp.163-171
• /
• 1994

The effects of diesel oil on the microbial community in sandy loam soil were investigated, and the effects of bioremediation which was performed to enhance the removal of diesel oil from soil were also measured. The residual percentage of diesel oil was about 50% after 16 week incubation period. The bioremediation treatment increased the removal rate at 60~95%. When the soil was contaminated with diesel oil, the direct bacterial count, length of fungal hyphae, aerobic heterotroph and hydrocarbon degrader were increased by 2~3 orders of magnitude. The bioremediation further increased these numbers 10 to 100-fold. There were no difinite patterns of change in fluorescein diacetate hydrolysis activity in bioremediation-untreated soil, but about 10 times of increase of activity was observed in bioremediation-treated soil. Similar change was occurred in soil dehydrogenase activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.7
• /
• pp.1030-1037
• /
• 2010

A fresh juice has become a new functional food available for dieting and health. However, the shelf-life of vegetable juice is very short because of the absence of heat pasteurization process. To elongate the shelf-life of vegetable juices, such as Angelica keiskei and Brassica loeracea var. acephala, the changes of microbiological, chemical and sensory property by UV irradiation were investigated. The total aerobic bacterial numbers of A. keiskei and B. loeracea var. acephala vegetable juices were $3.2{\times}10^5$ and $7.0{\times}10^4\;CFU/mL$, respectively, after wring process. However, the numbers were $3.6{\times}10^3{\sim}9.7{\times}10^3$ and $3.7{\times}10^3{\sim}2.7{\times}10^4\;CFU/mL$ after UV treatment on wring juice, and this lower microbial number was maintained during storage. The number of coliform bacteria also reduced significantly by UV treatment, and the bactericidal effect was higher when the flow rate is slower. The increase of lightness and yellowness, and decrease of redness were observed after treatment of UV on both vegetable juices, but the differences were not significant between flow rates. The ascorbic acid contents of vegetable juices were reduced by UV irradiation regardless of flow rate, and storage. Overall acceptance in sensory analysis revealed that there was no significant difference between the control and vegetable juice irradiated UV at 0 days, but sample with UV treatment showed higher score at 3 days. Therefore, UV treatment on vegetable juice can elongate the shelf-life without any problems in flavor and color.