• Korean Journal of Food Science and Technology
• /
• v.34 no.5
• /
• pp.792-798
• /
• 2002

Investigations on the microbiological, physicochemical, and sensory characteristics of seasoned Galbi using various packaging methods during storage at $-1^{\circ}C$ revealed no significant differences in pH values and acidities of seasoned Galbi depending on packaging methods and storage periods. Increments of thiobarbituric acid values of seasoned Galbi with non-evacuated packaging and modified atmosphere packaging were superior to those of vacuum packaging and double-film vacuum packaging during storage. Seasoned Galbi with non-evacuated packaging showed the highest volatile basic nitrogen value, and total plate count significantly increased compared to other packaging methods after 15 days storage. Coliform bacteria showed an average count of 2.35 log CFU/g at the beginning of storage, which increased slightly from 7 to 15 days, and was maintained under 4.0 log CFU/g after 15 days storage. The sensory evaluation revealed that non-evacuated packaging scored relatively lower than other methods in color, flavor, off-odor, and overall acceptability after storage.

• Korean Journal of Food Science and Technology
• /
• v.21 no.2
• /
• pp.283-288
• /
• 1989

The effect of storage temperature on the quality characteristics of meat sausage was investigated. Thus, the quality characteristic changes of meat sausage were discussed through physico-chemical and microbiological analysis. The results were summarized as follows; Volatile basic nitrogen(VBN) was increased more rapidly at $40^{\circ}C$ than at $10^{\circ}C$, $20^{\circ}C$ and fluctuating temperature $(10/40^{\circ}C)$. In physico-chemical analysis of meat sausage, the values of VBN , viable cell counts were increased with increase of temperature during storage, while thiobarbituric acid(TBA) values were fluctuated during storage as a whole. Water activity(Aw) and moisture contents showed a little change according to storage temperature, but sausage color was darkened as storage time goes by as a whole, the shelf-life was predicted above 40 days at $10^{\circ}C$, below 40 days at $20^{\circ}C$, below 30 days at $40^{\circ}C$ and about 20 days fluctuating temperature $(10/40^{\circ}C)$, respectively on the basis of slime formation in sensory evaluation.

• Journal of Environmental Health Sciences
• /
• v.36 no.3
• /
• pp.229-235
• /
• 2010

Efforts to evaluate water pollution using indicator microorganisms have been underway for decades, and driven by research on water purity control applications, water quality criteria are growing more and more strict. Furthermore, recent reports indicate that high concentrations of antibiotics are not absorbed, and are present in excrement from animals and humans dosed with unnecessarily high levels of antibiotics. This has emerged as very important issue from the standpoint of being an ecological and health hazard. In this study, water pollution was analyzed through physicochemical and microbiological means, and antibiotic resistance in indicator microorganisms was assessed. In physicochemical analysis, biochemical oxygen demand (BOD)$_5$ and chemical oxygen demand (COD)$_{Mn}$ evaluation showed that pollution by organisms was highest at the G1 location with a high human population, and the DP location which has many livestock-containing households. The indicator organism levels at the G1 location were: Total Coliforms (1205 colony forming units (CFU)/100 ml), Fecal Coliforms (270 CFU/100 ml), Escherichia coli (253 CFU/100 ml) and Fecal Streptococci (210 CFU/100 ml), while for the DP location levels were: Total Coliforms (1480 CFU/100 ml), Fecal Coliforms (438 CFU/100 ml), E. coli (560 CFU/100 ml), and Fecal Streptococci (348 CFU/100 ml). Levels of fecal indicator microorganisms such as Fecal Coliforms, E. coli and Fecal Streptococci were high at all locations in the fall (the period after the rainy season), and the yearly distribution was similar between these organisms. If the number of livestock-containing households was high, almost all strains of E. coli (as distinct from the other indicator organisms) showed resistance to antibiotics, with the degree of resistance varying between areas. E. coli strains from the OY area in particular, which has a high population density, showed strong resistance to AM10 and Va30. While strong antibiotic resistance was observed overall at the DP and OY locations, no resistance was observed at the EB location.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.377-384
• /
• 2008

The gamma irradiation process was performed to prolong a shelf-life of peaches and the effects of a gamma irradiation on the nutritional, physiochemical and sensory characteristics of peaches were evaluated during a post-irradiation storage at $4^{\circ}C$ and $25^{\circ}C$. Nutritional, physiochemical and sensory characteristics of peaches were stable at 1 kGy of an irradiation, a recommended dose for fruits and vegetables by CODEX, and the viable cell counts of contaminated microorganisms were reduced by 2 decimal reduction, at this dose. After a 1-week storage at ambient condition, the microbiological quality of the 1 kGy irradiated peach was stable, while all the non-irradiated peaches were deteriorated Furthermore, cold storage enhanced the shelf-life of the gamma irradiated peach and the nutritional and physiochemical characteristics of the peaches were comparatively stable up to 6 weeks. Right after gamma irradiation, the sensory evaluation results were not different in any of the samples, and the sensory quality of the irradiated peaches was adequate for a 4-week storage at $4^{\circ}C$. Our results suggested that gamma irradiation at 1 kGy can be used to enhance the shelf-life of peach without a significant loss in the quality attributes, especially upon cold storage after radiation treatment.

• Korean Journal of Microbiology
• /
• v.44 no.4
• /
• pp.352-357
• /
• 2008

We evaluated cultivation methods to obtain pure cultures of previously uncultivated bacteria from soil. Soil bacteria (suspensions) were inoculated onto various oligotrophic media with one of the following additives: 1) soil extract; 2) anthraquinone disulfonate (humic acid analogue); 3) acyl homoserine lactones (quorum-signaling compounds); 4) catalase (for the protection of bacteria from exogenous peroxides). After the relatively long period (60 days) of incubation with elevated concentrations of $CO_2$ (5%, v/v), the media containing catalase showed the highest colony count. We purified 147 randomly selected colonies from the media and the isolates were subjected to the phylogenetic analyses of their 16S rRNA gene sequences. Phylogenetic analysis revealed that approximately 30% of the isolates might belong to novel species or novel family, suggesting that the media and incubation conditions used could be useful for the cultivation of as-yet-uncultured bacteria. Especially, bacteria belonging to the phylum Acidobacteria, ubiquitous bacterial taxon known as an uncultured bacterial group (at least difficult to culture from environmental samples), were successfully cultured in this study.

• Journal of Animal Science and Technology
• /
• v.49 no.4
• /
• pp.515-522
• /
• 2007

To develop the manufacturing method of ice cream with microbiologically safe and proper sensory quality using irradiation for sensitive consumer, 3 different flavors, which were resistant to their flavors against irradiation, were selected and used for ice cream manufacturing to reduce the irradiation-induced off-flavor problem. The general composition was not different among treatments. Total aerobic bacteria were detected as 2.38, 1.23, 1.38, and 1.15 log CFU/g level in ice cream with control(no flavor added), spearmint, mint, and citrus flavor, respectively. No viable cells were observed by irradiation at 1 kGy except for the control. Sensory evaluation indicated that the irradiated ice cream with spearmint flavor at 1 kGy and citrus flavor at 3 kGy had higher overall acceptability. Therefore, a low dose irradiation (less than 3 kGy) with mint or citrus flavors may enhance the safety of ice cream with proper sensory quality for sensitive consumer.

• Journal of Microbiology
• /
• v.43 no.4
• /
• pp.337-344
• /
• 2005

Although pneumococcus is one of the most frequently encountered opportunistic pathogen in the world, the mechanisms responsible for its infectiveness have not yet been fully understood. In this paper, we have attempted to characterize the effects of pneumococcal transformation on the pathogenesis of the organism. We constructed three transformation-deficient pneumococcal strains, which were designated as Nos. 1d, 2d, and 22d. The construction of these altered strains was achieved via the insertion of the inactivated gene, comE, to strains 1, 2 and 22. We then conducted a comparison between the virulence of the transformation-deficient strains and that of the wild-type strains, via an evaluation of the ability of each strain to adhere to endothelial cells, and also assessed psaA mRNA expression, and the survival of hosts after bacterial challenge. Compared to what was observed with the wild-type strains, our results indicated that the ability of all of the transformation-deficient strains to adhere to the ECV304 cells had been significantly reduced (p < 0.05), the expression of psaA mRNA was reduced significantly (p < 0.05) in strains 2d and 22d, and the median survival time of mice infected with strains Id and 2d was increased significantly after intraperitoneal bacterial challenge (p < 0.05). The results of our study also clearly indicated that transformation exerts significant effects on the virulence characteristics of S. pneumoniae, although the degree to which this effect is noted appears to depend primarily on the genetic background of the bacteria.

• Korean Journal of Food Science and Technology
• /
• v.34 no.4
• /
• pp.565-569
• /
• 2002

This study was carried out to estimate the effects of preservatives (alcohol, adipic acid) and heat treatment $(40^{\circ}C,\;60^{\circ}C)$ for the prolongation of shelf-life on low-salt Kimchi. Low-salt Kimchi was prepared with salt replacements (NaCl 50%, KCl 36%, $MgSO_4$ 10%, $CaSO_4$ 3%, glutamic acid 0.2%). Chemical characteristics and microbiological parameters were monitored during fermentation at $20^{\circ}C$. When three kinds of preservative which were alcohol 2.0%, adipic acid 0.1% and their mixture were added to low-salt Kimchi, shelf-life of them were prolonged. To extend the shelf-life of low-salt Kimchi, when the heat treatment at $40^{\circ}C$ and $60^{\circ}C$ were tried, heat treatment at $60^{\circ}C$ was superior than at $40^{\circ}C$. In sensory evaluation of low-salt Kimchi, the control was showed the best quality in the overall acceptability. And low-salt Kimchi treated at $40^{\circ}C$ showed the most similar characteristics to the control Kimchi.

• Korean Journal of Food Science and Technology
• /
• v.34 no.4
• /
• pp.647-651
• /
• 2002

Eleven salt replacements$(SR-1{\sim}SR-11)$ composed of NaCl, KCl, $MgSO_4,\;CaSO_4$, lysine or glutamic acid were prepared and used for the preparation of low salt Kimchi instead of NaCl alone. Some chemical and microbiological characteristics of the low-salt Kimchi with 2.5% salt replacement were determined during the fermentation at $20^{\circ}C$. The pH decrease and acidity increase of low-salt Kimchi were slower than those of control Kimchi with NaCl alone. The total number of microorganism in SR-8 Kimchi added L-lysine was lower than that of control Kimchi until 5 days of fermentation. However, there was no difference in the numer of lactic bacteria between low-salt Kimchi and control Kimchi. The growth of yeasts was found to be slow in low-salt Kimchi with SR-8. The low-salt Kimchi with SR-3 showed the hardest texture among the prepared Kimchi. The overall acceptabilities of low-salt Kimchi prepared with SR-1, SR-3 composed of NaCl, KCl, $MgSO_4,\;CaSO_4$, and SR-10 added 0.2% glutamic acid to the elements were similar to the control Kimchi.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.11
• /
• pp.4924-4931
• /
• 2011

This research performed to evaluate a production processes reporting by the HACCP system of green vegetable juice products, containing lactic acid bacteria, stage of processing raw materials agricultural products and production facilities of general bacteria and pathogenic micro organism. General bacteria are found from four samples of storage of agricultural products at process stage and water was detected 8.67~14.67 CFU/ml. However, all samples were detected less than 105 CFU/ml as a legal standards after the process of UV sterilization. For the outcome of experiment of E.coli, E.coli O157:H7, B.cereus, L.moonocytogenes, Salmonella spp, Staph.aureus as the food poisoning bacterial, E.coli was detected until UV pre-step process in storage process and B.cereus was detected partly till 1st washing. Since all bacterial, Yeast and Mold are detected in main materials, pre-control method is a necessary to establish for decreasing with a number of initial bacteria of main materials and it is considered to establish the effective ways of washing and sterilization such as production facilities for cross contamination prevention of bacteria and Sthaphylococcus. Based on above results, the process of UV sterilization should be managed with CCP as an important process to reduce or eliminate the general and food poisoning bacterial of green vegetable juice products, including lactic acid bacteria. Therefore, it is considered to need an exhaustive HACCP plan such as control manual of UV sterilization, solution method, verification, education and training and record management.