• Advances in environmental research
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• 제2권1호
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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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• 제9권3호
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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.

• 급식외식위생학회지
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• 제2권2호
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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.

• 한국식생활문화학회지
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• 제18권2호
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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.

• 한국식품저장유통학회지
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• 제4권1호
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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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• 제9권2호
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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.

• 한국식품조리과학회:학술대회논문집
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• 한국식품조리과학회 2003년도 추계학술대회 및 사단법인 창립총회
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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)

• 한국식품영양학회지
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• 제10권4호
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• pp.553-558
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• 1997

냉동상태로 포장하여 판매되고 있는 생선(대구살)을 대구지역 수퍼마켓에서 구입하여 냉장(R:refrigerating), 냉동(F:freezing), 냉장과 동결을 반복(RFR:repeated freezing and refrigerating)하는 3군으로 나누어 저온저장하면서 저장중의 중온균과 저온세균의 수, free drip량과 pH의 변화를 측정하여 이들의 상관관계를 비교하였다. 저장직전의 해동어육의 생균수는 중온균이 6.5$\times$104, 저온세균이 7.4$\times$103cells/g이었으며 냉장한 시료에서는 저장 8일, 냉장과 동결을 반복한 시료에서는 저장 16일 후에 107cells/g을 초과하여 초기 부패에 도달하였다. 동결시료의 경우에는 46일간의 전 저장기간 동안 저장 28일째에 약 106cells/g으로 생균수가 가장 많았으며 신선한 상태가 유지되었다. 저온저장 중 저장초기에는 중온균의 수가 약간 많았으나 저장기간이 경과하면서 저온세균의 수가 빠르게 증가하여 저장밀기에는 저온세균의 수가 중온균의 수보다 증가하였다. 저장 중 pH의 변화는 생균수의 변화에 비례하여 증가하였으며 r=0.73-0.96의 높은 상관관계를 나타내었다. 저온저장 중의 drip량은 냉장시료에서 27.06$\pm$9.75, 냉동시료에서 27.56$\pm$8.02%로서 전 저장기간 동안 drip량은 큰 변화가 업이 두 시료간에는 유의적인 차이를 나타내지 않았다. 냉장과 동결을 반복한 시료는 저장기간이 길어질수록 drip량이 증가하는 경향으로서(r=0.84) 전 저장기간 동안의 평균치는 33.97$\pm$10.70%로서 냉장과 냉동시료에 비하여 20%정도 높은 값을 나타내었고 냉장 및 냉동시료와 유의적인 차이를 나타내었다.

• 한국미생물·생명공학회지
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• 제26권3호
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• pp.221-225
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• 1998

Y-CB와 Y-UCB를 음용하였을 때, 장내 비피더스균수, 유산간균수, 대장균수 및 분변의 pH, 수분함량(%) 등 장내환경 변화에 어떤 영향을 미치는지 검토하였다. 시험 대상자는 20～30세의 건강한 성인 남녀 14명으로 하였으며 평상시의 분변 상태를 조사한 다음 요구르트를 하루 2병씩 식후에 음용하도록 하였다. 음용시험의 방법은 Y-CB와 Y-UCB를 2주간 1차 음용 시험후 2주간의 음용 중단 기간을 가졌으며, 다음 제2차 음용시험으로서는 1차 음용시의 공시요구르트를 교차음용 하면서 분변상태를 비교 분석하였다. Y-UCB의 음용중에는 음용전과 비교하여 비피더스균수(p<0.01)와 유산간균수(p<0.05)는 유의성있게 증가하였고, 수분, pH, 대장균수에는 변화가 없었다. Y-CB의 음용은 음용전과 비교하여 비피더스균수는 증가하였고(p<0.01), 대장균수는 감소하였으며(p<0.05), 유산간균수, 수분, pH는 변화가 없었다. 두 개의 공시 요구르트를 음용 전과 비교하면 음용중단 후에도 비피더스균수가 증가하였고, 낮은 pH를 지속하였으며, 유산간균수, 수분, 대장균수의 변화는 없는 것으로 나타났다 결과적으로 유산균발효유의 음용효과(비피더스균수, 유산간균수, 대장균수, pH, 수분함량의 변화측정 ) 비교에 있어서 본 실험에 사용한 Y-CB나 Y-UCB는 어느 것이나 거의 동등한 효과를 나타내었으며 통계적으로 유의 차가 없는 것으로 나타났다(p>0.05).

• Preventive Nutrition and Food Science
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• 제7권4호
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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.