• Journal of agriculture & life science
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• v.50 no.4
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• pp.169-177
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• 2016

This study was carried out to compare microbiological and hygienic quality characteristics of the products reached expiration date among meat products distributing in markets. A total of 20 meat products(6 hams, 3 bacons and 11 sausages) were examined for analyses of pH, Aw, TBARS, VBN, total aerobic microbial counts, and meat colors. The pH values of samples were between 5.33 and 6.59. The water activity (Aw) of samples ranged 0.90-0.93. TBARS and VBN values of samples were 0.11-0.59 and 2.37~14.75, respectively. The contaminated levels of total aerobic bacteria were less than 2.80 CFU/g. In meat color, L*, a*, and b* values of samples were in the range of 56-72, 5.2-34 and 0.7-16, respectively. It is suggested that the quality difference of meat products is attributed to the different additives and manufacturing processes. Therefore, we suggest that the results of this study are not only applied for evaluation of the microbiological and hygienic safety but also served as fundamental information for re-establishing the shelf-life of meat products.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.424-428
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• 2013

To identify risk factors for Legionella contamination, water quality variables routinely measured in examination of natural and city waters were meta-analyzed for significance of correlation to Legionella incidences. For evaluation of abundance of Escherichia coli as a risk factor, which is currently used as an indicator of Legionella contamination in an official guideline in Korea, odds ratio (OR) of above-cutoff total coliform counts for Legionella presence/absence was used as the effect size in the meta-analysis. The OR was estimated as 1.05 (0.36-3.12, 95% CI), and the probability of having identical odds reached 0.92. Also, ORs from individual studies showed significant heterogeneity (P=0.008), which contributed to 63% of total variance of the ORs. In the case of heterotrophic plate count (HPC), the OR for Legionella presence/absence was 2.72 (2.04-3.63) with highly significant deviation from identical odds (P<0.0001). ORs from different studies were seemingly homogeneous ($Q_{df=8}$=12.7, P=0.12). Turbidity and concentrations of chlorine, iron ion and cupper ion were other routine variables that could be considered as risk factors. However, statistical measures from different studies were not uniform enough to develop an appropriate effect size while the number of studies reporting the variables was also small (3-5). In conclusion, HPC appeared to be appropriate as indicator of Legionella contamination, rather than fecal bacteria contamination. HPC may imply abundance of habitats (amoebas and biofilms) of Legionella in water. This result warrants further studies for standardizing protocols and cutoff values to infer Legionella risks from HPC.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.510-521
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• 1998

The effects of two types of protein, soybean meal (SBM) and fish meal (FM); and two types of energy supplements, corn flour (CF) and paper pulp (PP), on intake of guinea grass (Panicum maximum), fibre digestion and microbial activities in four Merino rams with an average weight of $54.4{\pm}4.5kg$ were studied. Each animal was fitted with a ruminal cannula and a duodenal cannula at the proximal position. The animals were fed twice daily with chopped guinea grass (5 cm) ad libitum and one of the four dietary supplements: 170 g FM+268 g PP; 170 g FM+268 g CF; 200 g SBM+200 g PP or 200 g SBM+200 g CF. All the supplements were mixed with 100 g molasses. In sacco and in vivo digestibilities, digesta flow rates, fermentation and microbial population were studied in a $4{\times}4$ Latin square design with a $2{\times}2$ factorial arrangement of dietary treatments. The effects of energy or protein sources were not significant on grass intake of sheep. The potential degradabilities of NDF and ADF were not significantly affected by any of the supplements. However, the energy and protein sources had significant efects on disappearance rate of NDF and ADF. The disappearance rate of both NDF and ADF were significantly (p < 0.05) higher in animals fed PP when compared to animals fed CF. Animals fed FM also showed significantly (p < 0.03) higher disappearance rate of ADF than those fed SBM. Animals fed PP showed better digestion in the rumen and total tract. Total flow of NDF and ADF through the duodenum was not significantly affected by the various supplements. The mean rumen pH values (5.8-6.1) were not significantly different among the four different diets. The concentration of rumen ammonia was significantly (p < 0.0001) higher in animals fed SBM (235-266.4 mg N/L) supplement than in animals fed FM (174.9-179.7 mg N/L), while total VFA concentration was not significantly affected by both energy and protein supplements. Mean values of total VFA ranged from 72.5-82.3 mM. Molar proportions of acetate, propionate and butyrate were typical of a roughage type fermentation. Molar proportion of acetate was significantly (p < 0.0001) higher in sheep fed PP when compared to sheep fed CF. Animals fed FM had higher total viable bacterial counts, while animals fed CF showed higher protozoal numbers. Proportions of cellulolytic bacteria were only slightly higher in animals fed SBM or PP.

• Journal of Environmental Health Sciences
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• v.41 no.6
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• pp.397-404
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• 2015

Objectives: The aim of this study is to investigate microbial contamination in the school food service environment for the assessment of microbial food safety. Methods: We collected both swab samples from tables and desks and airborne bacterial samples from an elementary school (School A) and a high school (School B). Heterotrophic plate count, total coliform, Staphylococcus aureus, and Bacillus cereus were measured with selective media to quantify microbial concentration. PCR assay targeting 16S rRNA genes was performed to identify the strains of S. aureus and B. cereus isolated. In addition, we made a food service checklist for the locations to evaluate the food service environment. A Wilcoxon test was employed to examine the differences in microbial concentration between before lunchtime and afterwards. Results: Heterotrophic plate counts showed higher levels after-lunch compared to before-lunch at School B. However, levels of S. aureus were higher in the after-lunch period (p<0.05) in both classrooms and in the cafeteria in School A. B. cereus was only sparsely detected in School B. Several samples from food dining carts were found to be contaminated with bacteria, and facilities associated with food delivery were found to be vulnerable to bacterial contamination. Although microbial concentrations in the air showed little difference between before- and after-lunchtime in the cafeteria in School A, those in classrooms were greater after-lunchtime at both schools. Conclusion: Our results suggested that the microbial safety in schools after lunchtime of concern. Necessary preventive measures such as hygiene education for students and food handlers should be required to minimize microbial contamination during food service processes in schools.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.265-276
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• 1999

This study was performed to evaluate the effect of hydrogen peroxide-producing Lactobacillus acidophilus V-20onthe replication of periodontal pathogens, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. When A. actinomycetemcomitans and P. gingivalis were incubated alone and in the combination with L. acidophilus V-20, the viable cell numbers of A. actinomycetemcomitans and P. gingivalis were compared between those cultures. The effect of S. mutans, E. durans, and L. lactis on the replication of A. actinomycetemcomitans and P. gingivalis was also evaluated. The change of periodontal indexes(probine depth, gingival index, GCF volume) and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides in subgingival plaque sample were evaluated following gargling of fermented milk made from L. acidophilus V-20 for 1 month on patients with periodontal disease in maintenance phase. In the mixed culture of L. acidophilus V-20 and A. actinomycetemcomitans or P. gingivalis, the replication of A. actinomycetemcomitans or P. gingivalis wascompletely inhibited. But in the mixed culture of P. gingivalis and hydrogen peroxide-nonproducing Lactobacillus casei, the viable ceil numbers of P. gingivaliswas not decreased when compared with the numbers in the mixed culture of P. gingivalis and L. acidophilus V-20. In the mixed culture of A. actinomycetemcomitans and S. mutans, E. durans, or L. lactis, the viable cell number of A. actinomycetemcomitans was not almost changed when compared with the numbers in the culture of A. actinomycetemcomitans alone. And in the mixed culture of P. gingivalis and E. durans or L. lactis, the viable cell numbers of P. gingivaliswas not almost changed compared with the counts in the culture of P. gingivalis alone. But the replication of P. gingivalis was completely inhibited in the mixed culture of P. gingivalis and S. mutans. When the change of periodontal indexes following gargling of fermented milk was compared with baseline, probing depth and gingival index were not changed, but GCF volume was significantly decreased(p<0.05). And when the viable ceil numbers of microorganisms in subgingival plaque sample were compared with baseline, total viable ceil number was almost unchanged and the viable cell numbers of A. actinomycetemcomitans and black pigmented bacteroides were significantly decreased(p<0.05). These results suggest that L. acidophilus V-20 inhibit the replication of A. actinomycetemcomitans and black pigmented bacteroides by the formation of hydrogen peroxide.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.221-226
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• 2001

Various sterilization methods were applied to the powder of ginseng for the improving hygienic quality. Ultra-violet (UV) and Infrared ray (IR) treatments could not inhibit highly growth of bacteria in ginseng powder. However, high hydrostatic pressure treatment showed high inhibition rate against bacterial growth in ginseng powder. Changes of viable cell count by the pressure showed positive relationship between growth inhibition rates and the pressures applied. When powder was treated with 2,000 kg/$\textrm{cm}^2$ for 10 min at $25^{\circ}C$, initial viable cell count of the powder, 2.0$\times$10$^4$CFU/g, was decreased to 1.0$\times$10$^4$CFU/g. When it treated with 3,000, 4,000 and 5,000 kg/$\textrm{cm}^2$ of pressures under the same condition, viable cell counts were 8.0$\times$10$^3$, 7.0$\times$10$^3$and 1.8$\times$ 10$^3$CFU/g, respectively. Ginseng saponins of the powders were all detected when analyzed by TLC chromatography after treatment with the Pressures. Therefore, it was considered that saponin of ginseng powder was stable under the condition of 5,000 kg/$\textrm{cm}^2$ of pressure, even though the treatment induced coagulation of the powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1422-1429
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• 2009

Alaska pollock roe is mainly used as a raw material for fermented seafood, especially in the East Asia. Kernels of Alaska pollock roe are not valuable as a raw material and usually discarded as a waste product. In order to utilize the broken roes of Alaska pollock, the smoked product, a imitated sausage, was manufactured for commercial production. Texture intensity (hardness and gumminess) and sensory evaluation (taste and acceptability) of the smoked Alaska pollock roe packed with collagen casing were evaluated based on mixture design and regression models. At higher concentration of carrageenan and lower concentration of starch in the formula of the smoked Alaska pollock roe, higher texture intensity and sensory scores were obtained. pH values of all treatments (control, vacuum and $N_2$ packages) increased up to 6.28, 6.23 and 6.24 on 4 months of storage, respectively, and then decreased. The numbers of VBN, TBA and viable cell counts increased during storage periods, higher in control than in vacuum and $N_2$ packages. Coliform bacteria was not detected in all treatment during storage periods.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1821-1828
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• 2013

This study was conducted to investigate the physicochemical and microbial properties of Makgeolli supplemented with kiwifruit (Actinidia deliciosa). Four hundred grams of kiwifruit were added to 3.1 L of distilled water, followed by 2.0 kg of rice, 40.0 g of Nuruk, and 14.0 g of yeast. The mixed rice solution was then fermented at $28^{\circ}C$ for 6 days to prepare the kiwifruit Makgeolli. The pH values of the kiwifruit Makgeolli decreased from 5.31 to 4.37, but the total acidity values increased from 0.05 to 0.34% during fermentation. The total viable cells ($3.18{\times}10^7$ and $2.88{\times}10^7$, respectively), lactic acid bacteria ($1.51{\times}10^6$ and $1.50{\times}10^6$, respectively), and yeast counts ($1.96{\times}10^7$ and $1.90{\times}10^7$, respectively) of the kiwifruit Makgeolli and control were similar throughout the fermentation process. Glucose was the major free sugar in the control and kiwifruit Makgeolli and significantly decreased during fermentation. Succinic acid was the highest organic acid in both the control (24.6 mg/mL) and kiwifruit Makgeolli (26.3 mg/mL). In a volatile compound analysis, 3-methyl-1-butanol, 2-methyl-1-propanol and ethyl acetate were the major volatile compounds in the kiwifruit Makgeolli.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.98-104
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• 2011

The storage quality of fresh buckwheat sprouts, as influenced by pretreatment and packaging within processing steps, was investigated to establish appropriate postharvest handling treatment for the commodity. After harvest, the sprouts were dipped in chlorine water (100 ppm), rinsed twice with clean water, pre-cooled with iced water, de-watered, and packed in plastic trays. Sprout samples taken from each processing step were stored at $5^{\circ}C$ for 6 days to measure quality attributes. Viable cell counts of mesophilic aerobes and coliform bacteria were lower by about 1 log scale in the postharvest treated samples compared to an untreated control, although the initial microbial reduction due to the postharvest treatments was offset by cell growth during storage. All sprout samples showed a decrease of fresh weight by approximately 4% after 6 days of storage. However, moisture and soluble solid contents were maintained at the initial levels of the sprouts. No significant difference in surface color was observed among sample treatments. For sensory properties including discoloration, wilting, decay, and visual quality, there were no significant differences among sample treatments. The present results suggest that proper postharvest processing treatments can exert positive effects on extending the shelf-life of fresh buckwheat sprout.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.132-140
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• 2017

Nuruk, a traditional Korean alcoholic beverage starter, was evaluated as an additional saccharifying agent comprising up to 1.5% (w/w) of malt weight in ale-type beer processing. Sample characteristics were monitored during fermentation, ripening, and storage. Beer containing nuruk showed higher numbers of total viable bacteria and yeast cell counts. Additionally, ethanol (6.19-6.35%), color (Standard Reference Method), foam stability ($228.49-368.24{Sigma}$), saccharogenic power (307-417), and reducing sugar (3.83-5.25%) increased as the amount of nuruk was increased, while viscosity (3.13-2.07 cP) and bitterness unit (19.68-13.13) were lower than in samples without nuruk. Overall acceptance and aftertaste of the beer were significantly higher in a preference test. These results demonstrate that nuruk can be used to produce a new type of ale.