• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.136-136
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• 2003

Calcium lactate has been known extending shelf-life of several lactic acid fermented foods through buffer action with lactic acid and binding of calcium and pectic polysaccharides in the tissue. But, the effects in kimchi during storage and distribution has not been observed. Calcium lactate is tasteless, nontoxic compounds commonly used in a number of food products. Recent observations have indicated the potential usefulness of calcium lactate as food additive which has anticariogenic-, antimicrobial-, anticalculus, anti- carcinogenic effects and enhancement of bone mineral density. In this work we determined the effects of calcium lactate(CaL)-treatment(0, 1, 2 and 3% against salted Chinese cabbage) on the pH, acidity, microbial counts, content of alcohol insoluble substance and calcium texture, color, scanning electron microscopic observation of kimchi tissue and sensory test during storage. pH of CaL treated kimchi were higher(3.78∼3.92) than that of control products(3.58). Total microbe(TM) of CaL treated kimchis were lower but ratio of lactic acid bacteria against TM was higher than those of control products, respectively. Calcium content of treated products were 3-5 times higher than control products. The hardness and crispy taste of treated products were remarkably higher than those of control products evaluated by SEM observation AIS analysis, sensory and textural analysis. Moreover, evaluation on the pH, acidity and sensory test showed the shelf-life of treated kimchi(CaL 2%) to be 25-30 days, which was 13-15 days longer than that of control products.

• Journal of Ecology and Environment
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• v.44 no.2
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• pp.72-80
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• 2020

Background: Antibiotics are widely used to treat animals from infections. After fertilizing, antibacterials can remain in the soil while adversely affecting the soil microorganisms. The concentration of oxytetracycline (OTC) in the soil and its effect on the soil microbial community was assessed. To assess the impact of OTC on the soil microbial community, it was added to the soil at concentrations of 50, 150, and 300 mg kg^-1 and incubated for 35 days. Results: The concentration of OTC added to the soil decreased from 150 to 7.6 mg kg^-1 during 30 days of incubation, as revealed by LC-MS. The deviations from the control values in the level of substrate-induced respiration on the 5th day of the experiment were, on average, 26, 68, and 90%, with OTC concentrations at 50, 150, and 300 mg kg^-1, respectively. In samples with 150 and 300 mg kg^-1 of OTC, the number of bacteria from the 3rd to 14th day was 2-3 orders of magnitude lower than in the control. The addition of OTC did not affect the fungal counts in samples except on the 7th and 14th days for the 150 and 300 mg kg^-1 contaminated samples. Genes tet(M) and tet(X) were found in samples containing 50, 150, and 300 mg kg^-1 OTC, with no significant differences in the number of copies of tet(M) and tet(X) genes from the OTC concentration. Conclusions: Our results showed that even after a decrease in antibiotic availability, its influence on the soil microbial community remains.

• Korean journal of food and cookery science
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• v.20 no.6 s.84
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• pp.561-567
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• 2004

The purpose of this study was to investigate the effect of Paecilomyces japonica mycelia(PJM) on pH, titrable acidity and microbiological qualify of Jeungpyun(fermented rice cake). Jeungpyun prepared with $0\~\%$ of PJM stored at $5^{\circ}C\;and\;20^{\circ}C$ for 4 weeks and 7 days respectively. Before fermentation of Jeungpyun dough, viable cells of total bacterial counts(TBC), yeasts and lactic acid bacteria(LAB) were $6.0\~9.8\times10^6,\;5.3\~9.0\times10^6,\;5.4\~8.5\times10^6\;CFU/g$, respectively. During the fermentation of dough, viable cells of TBC, yeasts and LAB increased $0.3\~0.4$ log cycle and pH was decreased whereas acidity increased as the progress of fermentation. Total viable cells in Jeungpyun before storage were $5.0\times10^1\;CFU/g$. During storage of Jeungpyun, TBC, yeasts and LAB of control group increased 2.6, 2.4, 2.1 log cycle at $5^{\circ}C$ and 4.8, 4.6, 4.5 log cycle at $50^{\circ}C$, respectively, when reached at maximum level. Major microflora of Jeungpyun was composed of yeasts and LAB during fermentation of dough and storage at $5^{\circ}C\;and\;20^{\circ}C$. Addition of PJM, inhibited the growth of microorganisms, the changes of PH and titrable acidity of Jeungpyun during storage at both of $5^{\circ}C\;and\;20^{\circ}C$. From these results, the addition of PJM extended the shelf-life of Jeungpyun during storage at $5^{\circ}C\;and\;20^{\circ}C$.

• Food Science of Animal Resources
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• v.23 no.1
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• pp.50-55
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• 2003

Fresh ground pork was irradiated with the electron beam(3.0 and 5.0 kGy) using 2 different conveyer speeds (10 and 20 ㎐), respectively, in order to determine the effect of conveyer speeds on the development of lipid oxidation and microbial stability. During refrigerated storage, the development of lipid oxidation decreased significantly (p<0.05) with the increase in the electron beam conveyer speed from 10 to 20 ㎐. The ground pork with electron beam inhibited the growth of total aerobic bacteria and mesophiles. The inhibitory effect increased when the electron beam dose increased from 0 to 5.0 kGy. The finding that higher speed(20 ㎐) of electron beam had some antioxidative effect is very promising, however, other means to control the lipid oxidation must also be employed to fully utilize the sterilization effect of electron beam in ground pork.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1830-1836
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• 2003

Studies using natural resistance-associated macrophage protein (NRAMP) identification indicated that cattle could be selected for immunity. Several studies performed on intracellular organisms such as Mycobacterium, Salmonella, Brucella and Leishmania in human and mouse revealed that resistance against these bacteria was dependent on high activity of NRAMP1 in macrophages. However, hardly any researches have been done on Staphylococcus aureus in bovine mastitis, which is an intracellular organism and the main cause of bovine mastitis. The objectives of this study were to establish reverse transcriptase polymerase chain reaction (RT-PCR) methods, through which NRAMP1 mRNA expression could be compared and analyzed between mastitis-resistant and -susceptible cows. NRAMP1 gene and its expression were investigated using 20 cows (Holstein Friesian) in Korea. Cows were evenly split into two groups, with and without histories of clinical mastitis. Equivalent numbers of cows were randomly selected from each group. Monocytes were isolated from the bovine peripheral blood of each selected cows and activated with lipopolysaccharide (LPS). mRNA was separated from the monocytes and cDNA of NRAMP1 was synthesized and amplified using RT-PCR with amplification of $\beta$-actin as a control. The difference in NRAMP1 expressions of mastitis-resistant (n=10) and -susceptible (n=10) Holstein cows was analyzed. Results demonstrate that resistant cows produced more NRAMP1 mRNA than the susceptible ones, and ratios of NRAMP1:$\beta$-actin expression were higher in resistant cows with or without LPS activation. Therefore, this study could be applied to select bovine mastitis resistant cows before infection based on the expression of NRAMP1.

• Korean Journal of Organic Agriculture
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• v.19 no.4
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• pp.553-563
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• 2011

This experiment was conducted to determine the effect of nattokinase (NK) additives on milk production and composition, and blood metabolites in dairy cows. The two kinds of nattokinase with high fibrinolytic activity were produced by two strains of bacteria, Bacillus amyloliquefacines (NK1) and Bacillus subtilis (NK2). Total fifteen Holstein cows (average $1.83{\pm}0.37$ parity; average milk yield $23.2{\pm}3.2$ kg/d) were randomly assigned to three treatments (5 animals per treatment). Cows were fed TMR supplemented with 0g, 100g and 100g for control, NK1 and NK2 treatment, respectively for 4 weeks. Milk yield was significantly higher (p<0.05) for NK1 (22.89 kg/d) than for control (21.07 kg/d) and NK2 (21.36 kg/d). Somatic cell counts in NK treatments were significantly lower than that in control group (58,000 vs. 21,000 and 35,000 cells/ml, control vs. NK1 and NK2). Serum ALT levels in all treatment were similar to the range of 32.00~35.83 IU/L, but AST levels in NK1 (85.67 IU/L) was significantly decreased compared with those in control and NK2 (121.67 and 117.67 IU/L respectively). Serum T-CHO levels in NK1 (145.33 mg/dl) was significantly decreased (p<0.05) compared with that in control (179.00 mg/dl) and NK2 (176.17 mg/dl). This finding showed that NK1 additives could possibly have a positive effect in lactation performance of mid-lactation dairy cows by increasing milk yield, reducing somatic cell count, improving liver function and decreasing cholesterol in blood.

• Korean Journal of Veterinary Research
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• v.55 no.4
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• pp.253-257
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• 2015

Oregano (Origanum vulgare) is an aromatic herb belonging to the Lamiaceae family. This study evaluated the therapeutic effect of oregano essential oil (OEO) on clinical bovine mastitis caused by Staphylococcus (S.) aureus and/or Escherichia (E.) coli. Thirty-two quarters from 18 lactating cows with subclinical mastitis were selected from a dairy farm and were divided into 4 groups (8 quarters/group): negative control (CON), positive control (GEN) and two OEO-treated groups (OEO-1 and OEO-2). Each group was intramammarily treated with saline, 10 g/tube of gentamicin ointment, and single and double doses of 0.9 mL OEO ointment twice a day for three days, respectively. After the treatments, physical udder conditions were greatly improved in GEN and OEO groups. In CON group, somatic cell counts (SCCs), number of white blood cells (WBC) and bacteria were increased. However, in OEO groups, SCCs and number of WBC were significantly decreased and S. aureus and E. coli were not detected in milk as compared with those before the treatments as well as GEN group. These results suggest that OEO may be a useful alternative to antibiotics for the control of subclinical bovine mastitis caused by S. aureus and/or E. coli.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.188-195
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• 2012

To produce rapidly the traditional Kanjang soy sauce-like product with rich flavors, lactic acid bacteria of Enterococcus spp. isolated from Chungkukjang was used as one of starter cultures. Among 119 Enterococcus spp., eight strains were selected by protease-secreting activities and identified as four E. faecium, three E. faecalis, and one E. gallinarium. The strains showed low resistances toward eight antibiotics and had no resistant genes to the vancomycin. Especially, E. faecium O24 was cultivated well on 5% NaCl medium that was selected for further study as the starter. E. faecium O24 grew well on the steamed soybean and the counts increased by ten times overnight, which produced mostly 80 mg% glutamic acid and aspartic acid as the seasoning amino acids on the product. Various organic acids including principal lactic acid were also produced. Flavors of maltol and guaiacol, typical soy-sauce flavor, were produced in the mixed cultures of Zygosaccharomyces rouxii and Candida versatilis. Therefore, E. faecium O24 could be a starter of soybean fermentation for soy sauce-like product with rich flavors rapidly.

• The Korean Journal of Food And Nutrition
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• v.27 no.2
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• pp.183-193
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• 2014

This study is conducted to evaluate the effects of gamma irradiation (0.4, 0.6, 0.8, 1 and 1.5 kGy) on the microbiological, physicochemical and sensory qualities of imported oranges during storage at $20^{\circ}C$ for 15 days. Total aerobic bacteria and yeast/mold counts in non-irradiated oranges increase significantly with increasing storage time. Irradiation has effects on the reduction of microorganism of dose-dependent oranges. The vitamin C contents decrease significantly according to dose-dependent manners and storage times after the gamma irradiation. Sensory evaluation decreases according to dose-ependent manners and storage times, excluding the color. The results suggest that gamma irradiation is effective for ensuring the microbiological safety, but the irradiated oranges more than 1 kGy are not good for physicochemical and sensory qualities. Therefore, irradiated samples of 0.4~0.6 kGy are considered as the optimum-dose for maintaining quality.

• Journal of Environmental Health Sciences
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• v.37 no.4
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• pp.298-305
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• 2011

Objectives: There has been a great amount of controversy in the food industry over the effectiveness of using gloves. The objectives of this study were to examine the microbial contamination of food handlers' hands and determine if using gloves could ensure safe handling of foods. Methods: Samples were collected through the glove-juice method from the bare and gloved hands of food handlers at work and were analyzed for the presence of aerobic plate counts, total coliform, fecal coliform, Escherichiacoli, Staphylococcus aureus, and Salmonella spp. Microbiological testing was conducted according to the Food Code of Korea. Results: Microbial contamination was consistently higher with bare hands than with gloved hands, although the microbial loads on both hands increased over time. Under certain conditions, there were significant differences between the bacterial loads on bare and on gloved hands (p<0.05). E. coli, S. aureus, and Salmonella spp. were still alive on both bare and gloved hands at the time the food handlers finished their work. Conclusions: Wearing gloves was associated with a marked reduction of bacterial contamination of the hands. However, the practice of continuously wearing gloves during food handling increases the potential for cross-contamination of bacteria. The findings of this study emphasize the need for a rational use of gloves, and strict adherence to hand hygiene compliance among food handlers.