• Food Science and Preservation
• /
• v.8 no.4
• /
• pp.393-398
• /
• 2001

Changes in physicochemical and microbiological properties of seafood bun containing kimchi were investgated during storage at 20$^{\circ}C$. pH of seafood bun tended to decrease and titratable acidity tended to increase during storage, as the kimrhi added more the pH was higher and titratable was lower. Acidity of seafood bun tended to increase during storage, the acidity was lower in seafood added kimchi than in control. Peroxide value of seafood bun added kimchi was lower than that of control, the value decreased with kimchi content. VBN and TBA values increased during storage, as the kimchi added more the value was lower. Viable colony and E. coli count significantly increased during 2 days of storage and tended to slightly increase afterward. The seafood bun added 20% kimchi obtained higher scores than other samples.

• Korean Journal of Veterinary Research
• /
• v.34 no.3
• /
• pp.517-527
• /
• 1994

An attempt was made to isolate a causative viral agents from the fecal specimens of the diseased dogs with the gastroenteritis symptoms. Two coronavirus-like agents were isolated by serial dilution end point method and plaque assay. The isolates were characterized in terms of cytopathology, antigenicity, replication, physicochemical and morphological properties. The results obtained through the experiment were as follows; 1. Among 7 fecal specimens collected from the dogs with enteric disease, 2(28.6%)coronavirus-like agents showing typical cytopathic effects of canine coronavirus were isolated, and designated as CCV D1 and CCV D2, respectively. 2. By the cross-neutralization test and indirect immunofluoresence antibody test, the isolates were antigenically indentified as the standard CCV. The viruses were replicated only in the cytoplasm of A-72 cells. 3. The isolates showed no haemagglutinating activity against the erythrocytes from 11 kinds of animals. 4. The electron microscopic observation for the isolates showed spherical and pleomorphic features, covered with club-shaped projections on the surface. The size of particles was ranged from 70 to 150nm. 5. In one-step growth curve for the isolates in A-72 cells, maximum titers of intracellular vius was $10^{4.6}$ $TCID_{50}/0.1ml$ at 46 hrs postinoculation(pi) of CCV Dl and $10^{4.4}$ $TCID_{50}/0.1ml$ at 34 hrs pi of CCV D2. The maximum titers of extracellular virus was $10^{5.5}$ $TCID_{50}/0.1ml$ at 58 hrs pi of CCV D1 and $10^{5.8}$ $TCID_{50}/0.1ml$ at 46 hrs pi of CCV D2. 6. In physicochemical property test, the isolates were very sensitive to choroform and were found to be RNA virus. The viruses was stable at pH 3.0 for 1 hr and at $22{^{\circ}C}$ for 5 hrs. However, infectivity titers reduced remarkably by treatment with $56{^{\circ}C}$ for 10min.

• Korean Journal of Food Science and Technology
• /
• v.33 no.5
• /
• pp.589-595
• /
• 2001

Effect of anti-microbial agents, such as alcohol, garlic, chitosan, K-sorbate, or mustard, or pasteurization on the quality of traditional kochujang was investigated during storage at $30^{\circ}C$ for 24 weeks. Water activities of kochujang decreased after 12 weeks of storage. Consistency increased during storage and highest consistency of kochujang was obtained by the addition of mustard or garlic. Hunter a- and b-values decreased linearly as storage time passed. The degree of increase in total color difference$({\Delta}E)$ of alcohol added group was the highest among the tested anti-microbial agents. Gas was rapidly produced in the control and chitosan added group of kochujang. Capsanthin content decreased more rapidly in the group of alcohol, garlic or mustard added kochujang than the other group. Viable cell counts of yeast and aerobic bacteria in kochujang increased up to 12 weeks of storage, and then decreased slowly. The number of yeast was low in K-sorbate or alcohol added group. Activity of ${\alpha}-amylase$ decreased during storage, but that of ${\beta}-amylase$ increased in alcohol, garlic, K-sorbate added or pasteurized kochujang. Protease activities did not show any remarkable differences in the groups of tested during storage.

• Food Science and Preservation
• /
• v.21 no.5
• /
• pp.652-660
• /
• 2014

To maintain the microbiological safety of Prunus mume fruit before it is processed, it was treated with a combination of 0.5% citric acid and 0.1% Tween 20, and stored at $4{\pm}1^{\circ}C$ for seven days. The combined treatment reduced total aerobic bacteria, yeast, and mold populations in the fruit by 2.20 and 1.70 log CFU/g, respectively, compared to those in the control. Organic acid contents and the Hunter $L^*$, $a^*$, and $b^*$ values were not affected by the treatment during the storage. In addition, the dried Prunus mume fruit prepared with 40% red algae extract (RAE) or maltodextrin (MD) treatment and hot-air drying were compared with respect to the fruit's physicochemical properties such as color, total phenolic and flavonoid content, and microstructure. The hot-air dried samples had undesirable color changes and inferior textures. The RAE-treated samples had a higher total phenolic content (225.15 mg gallic acid equivalent (GAE)/100 g) and total flavonoid content (49.25 mg quercetin equivalent (QE)/100 g) than the other treatments. The treatment of Prunus mume fruit with RAE can provide better-dried products than can MD treatment or hot-air drying. These results suggest that the combined treatment with citric acid and Tween 20 can be effective in preserving the microbiological safety of Prunus mume fruit, and its dehydration using RAE is an efficient drying method.

• Journal of Food Hygiene and Safety
• /
• v.28 no.1
• /
• pp.1-6
• /
• 2013

Ten commercially available red pepper powders were investigated for their hygienic quality (total aerobic count, yeasts and molds, and coliforms) and physicochemical properties (moisture content, pH, Hunter's color values, American Spice Trade Association (ASTA) color and particle size). Microbial analysis resulted in $10^3-10^6$ CFU/g of total aerobic count and same of yeasts & molds, where 2 samples were positive ($10^3$ CFU/g) for coliforms. The moisture contents (7.25% to 12.73%) were with in the range as described in the Korean Food Standards Codex. Noteworthy variations were observed in pH (4.97 to 5.15), Hunter's ${\Delta}E$ values (47.19 to 58.04) and ASTA color values (89.31 to 98.61). Although the color differences were evident among the samples, but the Hunter values were not in good correlations with ASTA color values. The average particle sizes of the all samples were comparable ranging from $605{\mu}m$ to $1251{\mu}m$ with few exceptions. There was a great variation in the key quality attributes of commercially available red pepper powders that should be considered for their various uses in food products.

• Korean Journal of Food Science and Technology
• /
• v.48 no.5
• /
• pp.486-491
• /
• 2016

Efficacy of dielectric barrier discharge-cold plasma treatment (DBD-CPT) for microbial decontamination of onion powder was evaluated. Onion powder, inoculated with Escherichia coli O157:H7, Salmonella Enteritidis, or Listeria monocytogenes, was treated with helium DBD-CPT. DBD-CPT (9 kV, 20 min) inhibited E. coli O157:H7, S. Enteritidis, and L. monocytogenes by $1.4{\pm}0.5$, $2.3{\pm}0.3$, and $1.2{\pm}0.0log\;CFU/cm^2$, respectively. The inactivation levels of E. coli O157:H7, S. Enteritidis and L. monocytogenes increased by $2.2{\pm}0.1$, $2.5{\pm}0.1$ and $1.9{\pm}0.3log\;CFU/cm^2$, respectively, as water activity increased from 0.4 to 0.8, and increased by $2.3{\pm}0.4$, $2.1{\pm}0.1$ and $1.6{\pm}0.1log\;CFU/cm^2$, respectively, as the particle size increased from 0.3 to $1.0cm^2$. Neither the ascorbic acid and quercetin concentrations nor the color of onion powder was changed by DBD-CPT (p>0.05). These results demonstrate the potential for application of DBD-CPT in improving microbiological safety of onion powder while preserving the physicochemical properties.

• Korean Journal of Plant Resources
• /
• v.20 no.4
• /
• pp.342-347
• /
• 2007

The present study was conducted to examine the effect of prunus mume extract on the Kimchi fermentation. The physicochemical and microbiological properties of Kimchi with the addition of various levels(0, 0.1, 0.3 or 0.5%)of prunus mume extract was measured up to 30 days at $4^{\circ}C$. pH was decreased sharply in control after 2 days . A typical decreasing pattern in pH values was noted in all treatments during the initial 18 days of fermentation followed by a gradual decrease afterwards. Total acidity was decreased by the addition of prunus mume extract. Reducing sugar content was reduced to approximately 70% by day 10-12 in prunus mume extract treatments. Total vitamin C content was reached to maximum on 6 days of fermentation and then decreased in all treatments. Reducing sugar and total vitamin C contents were slightly increased by the addition of prunus mume. Total viable cell number increased to reach peak on day 8 and then slowly decreased during the fermentation. Lactobacillus cell number in control treatment continued to increase to reach peak on day 12, while the numbers in prunus mume treatments reached peak on day 8-12 and then gradually decreased throughout the fermentation. The results of this study indicate that prunus mume extract causes to delay the Kimchi fermentation by slowing down pH drop and inhibiting the Lactobacillus cell growth.

• Korean Journal of Soil Science and Fertilizer
• /
• v.34 no.2
• /
• pp.134-144
• /
• 2001

This study was conducted to investigate physicochemical and microbiological properties during composting process when pig manure was composted with some bulking agents(Saw dust, Rice hull, Crushed wood). The pig manure consisted of 2.95% total nitrogen, 4.55% $P_2O_5$, 2.07% $K_2O$, 81.2% organic matter and 14.0 C/N, dry base. The inorganic content of bulking agents were similar one another, and C/N ratio was Saw dust 392. Rice hull 91.5, Crushed wood 266. The temperature of Saw dust composting slowly increased at initial stage, whereas one of Rice hull and Crushed wood rapidly increased and stabilized similarly to outdoor temperature after about 2 month. The pH of compost increased during initial 1 month after decreasing, but thereafter decreased rapidly. The C/N ratio rapidly decreased at initial stage, and it slowly decreased after 1 month. Total nitrogen somewhat increased according to composting process. Ammonium-nitrogen increased until 60th day, and thereafter it was rapidly inclined to decrease. The population of aerobic bacteria, Bacillus spp., actinomycetes and fungi increased up to > $10^{10}cfu\;g^{-1}$ fresh weight, > $10^7$, > $10^8$ and > $10^6$, respectively in Rice hull and Crushed wood composting, and more than ones in Saw dust composting, and specially actinomycetes. The persuasive Bacillus spp. isolated from composting process were B. lentimorbus, B. licheniformis, B. pumilus, B. megaterium, etc.

• Korean journal of food and cookery science
• /
• v.15 no.2
• /
• pp.178-184
• /
• 1999

Physicochemical, microbiological, and sensory properties of corns irradiated by gamma-ray at 1.2 kGy, 10.1 kGy or 30.5 kGy were investigated every 40 days during the storage at 25$^{\circ}C$ and 50% relative humidity. The moisture content of irradiated corns decreased and crude lipid content increased during the storage. Acid values of the irradiated corns were not significantly different from those of the nonirradiated corns but acid values generally increased during the storage. TBA values of irradiated corns increased in proportion to the irradiation dose and to the storage period. Numbers of mesophilic and psychrotrophic bacteria in the nonirradiated corns and 1.2 kGy dose-irradiated corns were higher than those in the corns irradiated at 10.1 kGy and 30.5 kGy at the late storage. The number of yeasts and molds in the nonirradiated corns were higher than those in the irradiated corns during the storage. In Hunter's color, L values of irradiated and nonirradiated corns decreased with the storage period and b values of all groups decreased except the group irradiated at 30.5 kGy. In sensory evaluation, fresh corn odor of the irradiated group was significantly different from those of the nonirradiated one stored for only 0 day and 200 days but raw corn odor and acidic odor were not significantly different among the groups depending upon the radiation dose and storage period.

• Microbiology and Biotechnology Letters
• /
• v.44 no.2
• /
• pp.150-155
• /
• 2016

This study investigated the effects of combined treatments of immersion liquid and high hydrostatic pressure (HHP, 100−400 MPa) on the quality of mackerel. In this study, we measured viable cell counts, pH level, color value, texture properties, and sensory evaluation of mackerel. Viable cell counts of mackerel treated with combined HHP were decreased by 2 log cycles at 300 MPa and 400 MPa compared to the control. The pH values of mackerel treated with HHP at 300 MPa and 400 MPa were higher than that of other samples. Hardness, gumminess, and chewiness decreased when treated with combined HHP and increased with increase in HHP. Lightness and whiteness of mackerel increased, but redness decreased, with increase in HHP. In case of sensory evaluation, texture of mackerel treated with HHP at 300 MPa and 400 MPa showed higher scores than that of other samples. These results suggest that immersion liquid and HHP treatments can increase microbiological safety and improve textural properties of mackerel.