• Advances in environmental research
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• v.2 no.1
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• pp.61-80
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• 2013

Quantification of viable forms of microbial community (bacteria and fungi) using culture-dependent methods was done in order to characterize the indoor air quality (IAQ). Role of those factors, which may influence the concentration of viable counts of bacteria and fungi, like ventilation, occupancy, outdoor concentration and environmental parameters (temperature and relative humidity) were also determined. Volumetric-infiltration sampling technique was employed to collect air samples both inside and outside the schools. As regard of measurements of airborne viable culturable microflora of schools during one academic year, the level of TVMCs in school buildings was ranged between 803-5368 cfu/$m^3$. Viable counts of bacteria (VBCs) were constituted 63.7% of the mean total viable microbial counts where as viable counts of fungi (VFCs) formed 36.3% of the total. Mean a total viable microbial count (TVMCs) in three schools was 2491 cfu/$m^3$. Outdoor level of TVMCs was varied from 736-5855 cfu/$m^3$. Maximum and minimum VBCs were 3678-286 cfu/m3 respectively. Culturable fungal counts were ranged from 268-2089 cfu/$m^3$ in three schools. Significant positive correlation (p < 0.01) was indicated that indoor concentration of viable community reliant upon outdoor concentration. Temperature seemed to have a large effect (p < 0.05, p < 0.01) on the concentration of viable culturable microbial community rather than relative humidity. Consistent with the analysis and findings, the concentration of viable cultural counts of bacteria and fungi found indoors, were of several orders of magnitude, depending upon the potential of local, spatial and temporal factors, IO ratio appeared as a crucial indicator to identify the source of microbial contaminants.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.206-212
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• 2004

Prickly pear extract (PPE) was fermented by Lactobacillus rhamnosus LS at 3$0^{\circ}C$ for 2 days. To improve the physicochemical properties of fermented PPE, it was fortified with food polysaccharides (0.2 %) or seaweed calcium before lactic acid fermentation. The viable cell counts, flow behavior, titratable acidity and color stability of fermented PPE were evaluated during 4 weeks of cold storage. Addition of xanthan gum or glucomannan increased the apparent viscosity and acid production, viable cell counts and red color of PPE were also well maintained during the cold storage. However, fermenting PPE with gellan gum resulted in a decrease in relative absorbance, indicating lower color stability. In particular, PPE fortified with carrageenan or alginic acid showed reduced acid production and lower viable cell counts. Addition of seaweed calcium at a 0.1 % level had positive effects on color stability, and helped maintain viable cell counts of 4.1 ${\times}$ 10$^{9}$ CFU/mL. This study demonstrated that xanthan gum could be used as a good thickening agent and stabilizer for retaining viable cell counts and red color during the cold storage in PPE fermented by lactic acid bacteria.

• Journal of the FoodService Safety
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• v.2 no.2
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• pp.84-90
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• 2021

This study was performed to assess the microbiological quality and safety of microgreen sampled from harvesting farms and food processing plant in Korea. The samples were analyzed for total viable counts, coliforms, Enterobacteriaceae, Escherichia coli, Salmonella spp., Listeria monocytogenes, Vibrio parahaemolyticus, Bacillus cereus, and Staphylococcus aureus. Total viable counts were highly contaminated in samples collected from farms (7.7~8.2 log CFU/g) and the final products (5.8~7.8 log CFU/g), respectively. B. cereus was detected less than 100 CFU/g, which was satisfied with Korean standards (<1,000 CFU/g) of fresh-cut produce. A predictive model was developed for the changes of total viable counts in microgreens during storage at 5~35℃. The predictive models were developed using the Baranyi model for the primary model and the square root model for the secondary model. The results obtained in this study can be useful to develop the safety management options along the food chain, including fresh-cut produce storage and distribution.

• Journal of the Korean Society of Food Culture
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• v.18 no.2
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• pp.134-138
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• 2003

Quality stability of the herb pill coated with edible oils containing rosemary was investigated. Herb pills were made of herb powders such as Panax ginseng, Cinnamomum cassia, Lycium chinense, Zyzyphus jujuba and Zingiber officinale. Rapeseed oil and lubriol were used as edible coating oil. After herb pills coated with edible oils with or without rosemary were stored at $40^{\circ}C$ for 180 days, the microbial viable cell counts and peroxide values(POV) of the herb pill were investigated. After 180 day storage, POVs of herb pills with only rapeseed oil or lubriol were 0.51 and 0.49 meq/kg, respectively. However, when rosemary was added in herb pills the POVs were decreased to 0.30 and 0.39 meq/kg, respectively. The addition of rosemary to the rapeseed oil and lubriol tended to decrease the microbial viable cell counts of the herb pill. The microbial viable cell counts of rapeseed oil and lubriol were 940 and 820CFU/g, respectively after 180 days of storage. However, these levels were suppressed to 720 and 640CFU/g by the resemary addition. On the other hand, the ginseng saponin content of herb pills was not affected by the rosemary addition during storage.

• Food Science and Preservation
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• v.4 no.1
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• pp.17-25
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• 1997

The effects of microwave treatment on the perservation of foods, such as a seaweed soup and sea stoned radish shreds, were studied. Microwave treatment of microbial cell suspensions revealed that viable cells decreased dramatically when heated to 6$0^{\circ}C$. However, it was unlikely that microwave treatment to 60 is enough to decrease the viable cell counts efficiently in a seaweed soup and radish shreds. It was thought that microwave heating to at least 7$0^{\circ}C$ as a final temperature was an important factor to reduce microbial cell counts in foods. When foods were heated to 7$0^{\circ}C$ with a repetitive 15 sec "on" followed by 30 sec "off", no big differences were observed in viable counts during storage at 2$0^{\circ}C$ for 3 days, as compared to those treated with a full power. The microwave treatment with three stages was designed to solve problems associated with variations depending on food volumes and difficulties of heat diffusion in a solid food to be irradiated with a microwave oven. The three stage method was found to have a similar efficiency in the reduction of viable cell counts in foods to microwave treatment at a full power and to conventional methods, such as water bath heating or boiling for 3 min with a gas range.in with a gas range.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.138-143
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• 2004

Soybean curd residues (SCR) obtained from hot and cold manufacturing processes were fermented by indigenous microorganisms, Lactobacillus rhamnosus LS and Bacillus firmus NA-l for 15 h at 37$^{\circ}C$. The pH, acidity, viable cell counts, and tyrosine content were evaluated in samples with variations in sugar, starter and type of SCR. The raw Doowon SCR (D-SCR, cold-processed) fermented by indigenous microorganism had a 0.9% acidity and 6.7 ${\times}$ 10$^{7}$ CFU/g viable cell counts, compared with the 0.11 % acidity and 6.7 ${\times}$ 10$^{6}$ CFU/g viable cell counts of raw fermented Pulmuwon SCR (P-SCR, hot-processed). After fermentation of raw P-SCR with 1 % glucose and 1 % L. rhamnosus LS starter, the viable cell counts, tyrosine content and acidity were 4.7 ${\times}$ 10$^{8}$ CFU/g, 16.3 mg% and 0.9%, respectively. In addition, the raw P-SCR fermented with Bacillus firmus NA-l as co-starter had a 0.45% acidity, 2.4 ${\times}$ 10$^{8}$ CFU/g lactic acid bacteria, and 3.3 ${\times}$ 10$^{6}$ CFU/g Bacillus sp. In particular, the tyrosine content was increased 5 fold. The drying of fermented SCR was completed by hot-air drying (5$0^{\circ}C$) within 12 h; the dried P-SCR and D-SCR had 1.8 ${\times}$ 10$^{7}$ CFU/g and 5.3 ${\times}$ 10$^{6}$ CFU/g viable cell counts, respectively. The concentrate of methanol extract from fermented D-SCR inhibited the initial cell growth of E. coli, Staphylococcus aureus and Pseudomonas aeruginosa in liquid culture.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2003.10a
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• pp.74-74
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• 2003

We investigated the microbial populations and viable cell counts of Codonopsis lanceolata from uncultivated and cultivated soil in the suing. The microbial populations and viable cell counts from both types of soils were also investigated simultaneously. It had existed 10 more kinds of microorganisms in uncultivated than those in cultivated. The total viable cell counts of C. laneolata from uncultivated soil, especially in the upper zone, were 9.7$\times$10$^{6}$ CFU/g. However, the C. lanceolata from cultivated soil was 4.2$\times$10$^{6}$ CFU/g. (omitted)

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.553-558
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• 1997

Frozen cod fillet block(7.0$\times$4.6$\times$0.6cm, 18$\pm$0.5g) was purchased from a supermarket in Taegu area. Three experimental groups of fish fillet, frozen-thawed cod fillet refrigerated at 5$^{\circ}C$(R), frozen at -2$0^{\circ}C$(F) and repeated freezing and refrigerating(RFR) every other day, were incubated at each temperature. Changes in the viable counts of mesophiles and psychrotrops, the amount of free drip and pH of cod muscle during cold storage were 6.5$\times$104 and 7.4$\times$103 CFU/g of muscle, respectively. The viable counts of cod muscle R and FRF exceeded 107 CFU/g within 8 days and 16 days, respectively, while the viable counts of cod muscle F were not exceeded 107 cells/g throughout the storage period. The viable counts of psychrotrops exceeded that of mesophiles at the end of cold storage period. The viable counts of cod muscle showed positive correlation with pH(r=0.73-0.96,the highest in RFR) during cold storage. The amount of free drip in cod muscle R, F and RFR was 27.06$\pm$9.75, 27.56$\pm$8.02 and 33.97$\pm$10.70%, respectively. The amount of free drip in RFR increased as the progress of storage.

• Microbiology and Biotechnology Letters
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• v.26 no.3
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• pp.221-225
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• 1998

Fourteen healthy volunteers ranged in ages from 20 to 30 were served to administrate two types of yoghurt (2 bottles/day) such as one added uncapsulated-Bifidobacteria (Y-UCB) and the other added capsulated-Bifdobacteria (Y-CB) for 4 weeks, and the changes of intestinal microflora and fecal properties were studied. After administration of Y-UCB, the viable cell counts of fecal Bifidobacteria (p<0.01) and Lactobacilli (p<0.05) were significantly increased, however, fecal pH, moisture content and tile viable cell counts of coliform bacteria in feces were not changed when they were compared to those before administration (control). After administration of Y-CB, the viable cell counts of Bifidobacteria were significantly increased (p<0.01) and viable cell counts of coliform bacteria were significantly decreased (p<0.05), however, fecal pH, moisture content, and viable cell counts of Lactobacilli were not changed when they were compared to those before administration. High level of fecal Bifidobacteria and low pH were maintained after 2 weeks from ceasing the administration of both types of yoghurt when they were compared to those before administration. In conclusion, there were not significant differences between two types, Y-CB and Y-UCB in the changes of fecal pH, moisture content, and the viable cell counts of Bifidobacteria, Lactobacilli, coliform bacteria after the administration.

• Preventive Nutrition and Food Science
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• v.7 no.4
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• pp.397-404
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• 2002

Soybean curd residue (SCR) was fermented by lactic acid bacteria, Lactobacillus rhamnosus LS and Entercoccus faecium LL, isolated from SCR. The pH, titratable acidify and viable cell counts were determined from the fermented SCR to evaluate the lactic acid production and growth of lactic acid bacteria. Optimal amounts of pretense enzyme and glucose, and ideal fermentation time for SCR fermentation were estimated by response surface methodology (RSM). Raw SCR fermented by indigenous microorganisms had 0.78 % titratable acidity, The acid production in SCR fermented by L. rhamnosus LS was greatly enhanced by the addition of glucose and lactose. However only glucose increased acid production by Ent. faecium LL. The proof test of SCR fermentation demonstrated that similar results for titratable acidity, tyrosine content and viable cell counts to that predicted could be obtained by the at optimized fermentation conditions. In the presence of 0.029 % (w/w) pretense enzyme and 0.9% (w/w) glucose, the SCR fermented by Ent. faecium LL showed 1.07% (w/v) of titratable acidity, 1.02 mg% tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts. With the SCR fortified with 0.033% pretense enzyme and 1.7% glucose, L. rhamnosus LS showed 1.8% (w/v) of titratable acidity, 0.92 mg% of tyrosine content and 2$\times$10$^{9}$ (cfu/g) of viable cell counts.