• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.120-129
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• 2017

This study assessed the safety of raw oysters Crassostrea gigas for consumption during processing in a processing plant. Bacterial contamination (e.g., viable cell counts, coliform groups, Escherichia. coli and pathogenic bacteria) and chemical contamination (e.g., heavy metals and shellfish toxins) were measured on raw oysters, a processing equipment, employees and work areas. No total mercury, lead, paralytic shellfish poison, diarrheic shellfish poison or norovirus was detected in any post-harvested oyster samples. However, the cadmium level ranged from 0.1-0.2 mg/kg. The viable cell count, E. coli and coliform group levels in post-harvested oysters ranged from 4.00-4.54 log CFU/g, ND-210 MPN/100 g and 110-410 MPN/100 g, respectively. The viable contaminating cell counts on employees, equipment and work areas were in the range of $0.90-3.46log\;CFU/100cm^2$. Airborne bacteria in the work areas ranged from 0.60 to 1.81 log CFU/plate/15 min. Thus, no significant health risks were detected in the processing plant.

• Food Science of Animal Resources
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• v.36 no.4
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• pp.558-565
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• 2016

The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.7-13
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• 2004

Lactic acid fermentation of prickly pear extract (PPE) was performed by Lactobacillus rhamnosus LS, Lactobacillus bulgaricus, and Lactobacillus brevis. The PPE was pasteurized to eliminate indigenous microorganisms as well as to dissolve the partially insoluble pulp. The PPE fermented without yeast extract by L. rhamnosus LS exhibited 0.57％ acidity and 3.5${\times}$10$^{8}$ CFU/mL bacteria count. With the addition of 0.2% edible yeast extract the PPE fermented by L. rhamnosus LS exhibited 1.15％ acidity,2.7${\times}$10$^{9}$ CFU/mL bacteria count and 95.0% retention of red color. When 5％ fructose syrup was added, the PPE fermented by L. rhamnosus LS had 1.09% acidity, 6.5${\times}$10$^{8}$ CFU/mL, and 97.7% retention of red color. With 1∼3% (w/v) concentrations of starter, the PPE fermented by L. bulgaricus and L. brevis showed 0.97% and 0.65% acidities, respectively. The viable cell counts from L. rhamnosus LS fermentation were higher compared with those of other LAB. During cold storage at 4$^{\circ}C$, the viable cell count was well maintained for 3 weeks, but then rapidly decreased. The red pigment was highly stable during cold storage for 4 weeks. The pasteurized PPE fortified with 5% fructose syrup, 0.2% yeast extract, and 0.05% CaCO$_3$ was successfully fermented by inoculating with 3% LAB and incubating at 3$0^{\circ}C$ for 2 days. Both viable cell counts and the red color of the fermented PPE were well maintained during cold storage for 3 weeks.

• Food Science and Biotechnology
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• v.16 no.2
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• pp.198-204
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• 2007

The objectives of this study were to determine the quality characteristics, antioxidant activity, and cytotoxicity of fermented ginseng wine at each fermentation step. In the first mash with and without ginseng, viable cell counts (total cell, lactic acid bacteria, and yeast) were maximum between 2 to 4 days of fermentation. At the beginning of fermentation, Brix and ethanol contents, and titratable acidity increased, while pH decreased rapidly. At 3 days of fermentation of the second mash with ginseng, the viable cell counts were similar to those without ginseng and then continually decreased. At the end of fermentation, the pH of the second mash with ginseng was 4.00, lower than the pH of the second mash without ginseng, which was 4.35. Alcohol contents of second mashes with and without ginseng were 12.2 and 11.8%, respectively. In the aging period of ginseng and rice wines, the pH, titratable acidity, Brix, and ethanol contents did not change markedly. The results of sensory evaluation showed that fermented ginseng wine had good flavor and high acceptability. In the 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity assay, fermented ginseng wine ($IC_{50}$: 0.394 mg/mL) showed higher antioxidant activity than fermented rice wine ($IC_{50}$: 0.884 mg/mL). The butanol fraction of fermented ginseng wine exhibited weak cytotoxic activity against P388 and HeLa cell lines.

• Food Science of Animal Resources
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• v.20 no.1
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• pp.56-63
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• 2000

This study was investigated the effects of the addition of adlay with levels of 1%(T1), 2%(T2), 3%(T3) and 4% (T4) in skim milk substrate on the physicochemical and microbiological properties of yoghurt during fermentation and storage period at 4$\pm$1$^{\circ}C$. Adlay yoghurt were fermented with the mixed cultures of YC-380, ABT-4 and ABT-D. Titratable acidity and pH values of all treatments were increased and decreased significantly(p<0.05) with fermentation period, respectively and increased and decreased slightly during the storage period, respectively. There were increased and decreased in order of all treatments fermented with YC-380, ABT-4 and ABT-D. Viscosity of adlay yoghurt increased rapidly in order of T4, T3, T2 and T1 during fermentation and slowly in order of T1, T2, T3 and T4 during the storage period. There were increased in order of all treatments fermented with ABT-D, YC-380 and ABT-4. The counts of viable cells of lactic acid bacteria in all treatments were rapidly and slightly increased during fermentation and storage period, respectively. There were increased in order of fermented with ABT-D, ABT-4 and YC-380 in all treatments. The counts of E. coli were not found in adlay yoghurt. In all treatments, T1 showed slightly high compared to that of control. Based on the results of this experiment, the optimum level of addition of adlay were 1% (w/v) for production of acid production, pH, viscosity and the counts of viable cells of lactic acid bacteria.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.169-175
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• 1997

This study was carried out to assess the effect of the chlorine treatment into water for processing chicken products in each stage of slaughtering, with a special viewpoint related with reducing the viable number of microorganisms by which the water and the chicken body were contaminated. The mean bacterial number on chicken samples after picking process was log5.37$\pm$0.20~5.84$\pm$0.160CFU/$\textrm{cm}^2$. When assessed by standard plate count method, it was the higher one than any other processing stage in which eviscerating, pinning, packaging, and chilling was followed in order of the mean bacterial number. The coliform bacterial numbers on carcasses after sampling from different processing stages were log2.11$\pm$0.63~2.88$\pm$0.25MPN/$\textrm{cm}^2, which show almost similar numbers in each processing stage. But, after chilling process the number was decreased slightly. The bacterial counts in the water for scalding and chilling showed log3.43 $\pm$ 0.59~5.06$\pm$0.21 and log4.30$\pm$0.21~6.62$\pm$0.33CFU/$m\ell$, respectively. In the coliform counts for the water taken out from the 2nd chilling tank, the number was log1.97$\pm$0.35~2.91$\pm$0.22MPN/$m\ell$ which showed higher than those of the 1st and the 3rd chilling tank water. The effect of chlorination in reducing the bacterial numbers was accepted at the residual chlorine concentration of 1$m\ell$/$\ell$by showing the reduction from $10^8$ to $10^4$CFU level and the numbers were decreased less than 10CFU at the concentration of 5mg/$\ell$, when assessed by viable cell counts. In conclusion, these results suggested that chlorination In chilling water with final concentration of 5mg/$\ell$was strongly recommended to reduce the bacterial numbers on final chicken products.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.728-737
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• 2003

To evaluate microbial data and salivary measurements from clinically compatible, culture-based screening procedures employed with children younger than 36 months old. Plaque and stimulated saliva specimens were collected from 87 children. The pH of each saliva sample was measured before and after 0.94% lactic acid was added. Specimens were diluted and plated on selective media and non-selective media. Data collected were counts of mutans streptococci (MS) and lactobacilli (LB). In addition, total viable counts (TVC) of specimens, salivary pH and buffering capacity were also assessed. Each variable was compared to caries status of subjects. According to this study, the results were as followed: 1. Highly significant correlation with caries rates were found for counts of MS and LB. 2. The specific counts/ml saliva or plaque above which caries is predicted, or below which caries is not predicted were as follows: 1) Saliva MS; $10^5$ 2) Plaque MS; $2{\times}10^5$ 3) Saliva LB; $10^3$ 4) Plaque LB; $10^3$. 3. Salivary pH and buffering capacity versus caries status were not significant. 4. Microbial screening methods based on mutans streptococci had higher predictive values and odds ratios than methods for lactobacilli. 5. MS counts were clearly the best indicators of caries status in young children. This measurement can easily be obtained in a dental clinical setting both by conventional culture techniques, or commercial kits for MS recovery.

• Journal of Microbiology and Biotechnology
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• v.3 no.3
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• pp.199-203
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• 1993

The bacteriocin produced by Pediococcus acidilactici KFRI 168 exhibited a wide antimicrobial spectrum including many strains of lactic acid bacteria, Listeria monocytogenes, Staphylococcus aureus, and Enterococcus faecium by both disk and deferred assay methods. Inhibition of Lis. monocytogenes and Stph. aureus were observed only from deferred assay. Gram-negative bacteria were not inhibited. Bacteriocin production was observed at 10 h, and was maximized at 16 h in MRS broth incubated at $37^{\circ}C$. In a beaker sausage fermented with P. acidilactici KFRI 168, viable counts of Stph. aureus, Salmonella, Escherichia coli, Clostridium perfringens, and Lis. monocytogenes were reduced by 2.8, 2.3, 2.4, 0.7, and 0.5 log CFU/g, respectively. Inoculated P. acidilactici KFRI 168 maintained its viable count of more than $10^8$ CFU/g during the whole fermentation period, and it took less than 8 h to reduce sausage pH below 5.

• Journal of Ginseng Research
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• v.20 no.3
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• pp.299-306
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• 1996

This study was undertaken to examine the effects of fresh ginseng on the physicochemical and microbiological changes in dongchimi juice fermented under various conditions. The pH was somewhat lower in dongchimi juice added with 2.0% and 4.0% of fresh ginseng than that without ginseng, whereas the titratable acidity was higher in dongchimi juice with 2.0% and 4.0% of ginseng addition than the control. The addition of fresh ginseng to dongchimi preparation increased the numbers of total viable bacteria, lactic acid bacteria including Leuconostac mesenterotdes in dongchimi juice during fermentation. The changes in the counts of lactic acid bacteria were similar to those of total viable cells throughout the experiment except the initial stage of fermentation. However, the number of Leucosfastoc mesenternidgs decreased after the palatable stage. Key words : Panax ginseng C.A. Meyer, dongchlmi juice, pH, titratable acidity, microbiological changes.