• Food Science and Preservation
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• v.16 no.6
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• pp.965-970
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• 2009

PCR technology has been widely used to detect and quantify microbial pathogens in foodstuffs, because the technique is rapid, sensitive, and selective. In this study, detection of contaminating pathogenic bacteria on shells of chicken eggs was performed using both a commercial multiplex polymerase chain reaction (PCR) kit and a viable count method employing a selective medium. The PCR kit was capable of detecting Campylobacter jejuni, Escherichia coli O157:H7, Staphylococcus aureus, Bacillus cereus, Vibrio parahaemolyticus, Listeria monocytogenes, Yersinia enterocolitica, Salmonella species, and Shigella species. Using the PCR method, five bacterial species were detected from 30 samples (33.3%) of 90 batches of eggs commercially available in a market. PCR products from B. cereus, S. aureus, L. monocytogenes, Y. enterocolitica, and E. coli O157:H7 were detected, and the numbers and frequencies of positive samples were 17 (18.8%), 12 (13.3%), 15 (16.6%), 16 (17.7%),and 4 (4.4%), respectively. None of any Salmonella species, C. jejuni, V. parahaemolyticus, or Shigella species was detected in this study. The results of PCR testing were confirmed using a typical viable count method employing a selective medium. We suggest that the multiplex polymerase chain reaction (mPCR) assay is a rapid and reliable method for detection of pathogenic bacteria contaminating eggs.

• Food Science and Preservation
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• v.20 no.6
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• pp.886-893
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• 2013

Several indigenous sulfite-resistant yeasts were isolated at the microbial succession stage of yeast flora during spontaneous fermentation of Campbell Early grapes using a YPD plate that contained 200 mg/L or 500 mg/L potassium metabisulfite. When they were applied to the wine fermentation using the Campbell Early grape and apple juices, strains S13 and D8 showed strong alcohol fermentation and good flavor production. They were identified as Saccharomyces cerevisiae in the phylogenetic analysis based on their ITS 1-5.8S-ITS II DNA sequences. The two yeast strains grew to a high cell density in the YPD media supplemented with 40%(w/v) glucose. They also grew rapidly in the YPD media at $40^{\circ}C$. While strain S13 showed some differences in cell density at the two temperatures, no marked difference was observed during the culture of strain D8. The strains grew relatively well at pH 5.0 and 9.0 compared with pH 7.0, which was the optimum pH for their growth. Especially, strain S13 cultivated in the YPD media at pH 9.0 grew to 93% of the growth of strain D8, which was obtained at pH 7.0.

• Korean Journal of Agricultural Science
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• v.26 no.1
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• pp.39-49
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• 1999

Curd yoghurts were manufactured by addition of chestnuts and walnuts which were special agricultural products in Chungnam area. The nut powders were added to the yoghurts in the given concentration of 1~4%. The yoghurts after 12 hours fermentation were examined for pH, acidity, cell counts of lactic acid bacteria, viscosity, chemical composition and sensory test and preservation of yoghurts. The results obtained were summarized as follows; 1. The chestnut powder decreased pH, whereas increased acidity in yoghurts, however, the walnut powder did not change significantly for pH and acidity in yoghurts. 2. The cell counts of lactic acid bacteria was higher for 2% chestnut powder yoghurt ($2.6{\times}10^9/ml$) than 2% walnut powder yoghurt ($1.7{\times}10^9/ml$) and control yoghurt. 3. The viscosity of yoghurt was higher for 4% chestnut powder yoghurt (3,225 centipoise) than control (1,638 centipoise) and 4% walnut powder yoghurt (2,010 centipoise). 4. The protein content of yoghurts were 3.99% for both 2% chestnut powder and 2% walnut powder yoghurts, and solid-non-fat contents of yoghurt were 15.10% for chestnut powder yoghurt and 13.65% walnut powder yoghurt. 5. The scores of sensory tests were higher in chestnut powder yoghurt for tastes, odor and texture, and in walnut powder yoghurt for tastes, odor and texture compared to control yoghurt. 6. When yoghurts were stored at $5^{\circ}C$ for 14 days for preservation test, the acidity and number of lactic acid bacteria were not changed significantly.

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.66-70
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• 2007

Lactobacillus fermentum YL-3 was encapsulated to increase acid tolerance and its total viability. After micro-encapsulation of L. fermentum YL-3 cells with sodium alginate and soybean oil, the morphology of the microcapsule was observed using confocal laser scanning microscopy (CLSM) after staining with pyronin Y and fluorescein isothiocyanate. The sizes of the microcapsules were 120-126 ${\mu}m$, 444-486 ${\mu}m$ and 401-463 ${\mu}m$ when manufactured at pH 2, 3 and 4, respectively. The microcapsule could hold live cells of L. fermentum YL-3 up to $1.2{\times}10^{7}$, $8.1{\times}10^{7}$ and $1.1{\times}10^{8}$ CFU/mL at pH 2, 3 and 4, respectively. The acid tolerance and preservative ability of L. fermentum YL-3 in microcapsule and macrocapsule at $4^{\circ}C$ and $25^{\circ}C$ were tested. L. fermentum YL-3 cells were evenly located in the alginate capsule matrix structure and the firmness of microcapsule was highest at pH 2. Micro-encapsulation showed the most effective acid tolerance at pH 2.0 and preservation of viability at $4^{\circ}C$. However, at $25^{\circ}C$, the macrocapsules showed more effective cell protection than the microcapsules. The application range for microcapsules could be wider than for macrocapsules in the food industry.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.317-319
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• 1999

The ciliate, Vorticella was often observed in the rotifer mass culture tanks as common co-existing organism. This Vorticella performed as a predator for aquatic bacteria population in the rotifer mass culture tanks. This study was carried out to investigate a cyst formation medium of Vorticella in the laboratory for keeping Vorticella seed. The test organism Vorticella sp. was isolated from culture water of rotifer mass culture tanks. The cyst of Vorticella was formed by dried-method for the formation and maintainance of cyst. MCCF (Marine Ciliate Cyst Formation) medium was used for cyst formation (incystment), preservation and return to moving cell (excystment) of the marine ciliate, Vorticella sp. The cyst shape and size were ellipical type and $30.51 \pm1.98\;\mu$m (Avg. $\pm$ SD) of minor axis and $28.89 \pm2.12\;\mu$m (Avg. $\pm$ SD) of minor axis (n=10), The Vorticella cyst was kept in the room temperature ($10\~35^{\circ}C$) and total dark condition (24D:0L) during 1 year. The preserved cyst was transferred to moving cell state (excystment) only by the addition of fresh sea water in the MCCF medium. The five Vorticella sp. moving cells of excysted from cysts showed the growth up to 912$\pm$64 cells/10 ml in MCCF medium during the culture period of 16 days. This MCCF medium was very useful tool for cyst formation and species preservation of marine ciliate Vorticella.

• Food Science and Preservation
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• v.12 no.5
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• pp.496-500
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• 2005

To develop functional food material using Rhodiola dumulosa(RD), the biological activities such as antioxidation, antiproliferation in the cancer cells and immuno-activity in macrophage cells were investigated with hexane, ethylacetate, n-butanol, methanol and water fractions of RD 80% methanol extract. Hydrogen-donating activities of hexane, ethyl acetate, n-butanol, methanol and water fraction were 28.30, 53.21, 35.48, 42.64 and 21.14%, respectively, at a concentration of 100 ${\mu}g/mL$, and the activity of ethyl acetate fraction was similar to as that of BHT. After treated for 48 hrs, the ethyl acetate fraction decreased the proliferation of the A549 and SW480 cells in a dose-dependent manner at concentration of 10, 50, and 100 ${\mu}g/mL$, the activities were higher than other fractions. Morphology of cells treated with the ethyl acetate fraction for 48 hr at 100 ${\mu}g/mL$ was distorted with shrank cell mass, and the cell number was lower than that of control cells the macrophage cells treated. The methanol fraction was significantly induced NO production compared with untreated control cells at above 10 ${\mu}g/mL$ concentration. These results indicate that RD would be used the functional food material.

• Food Science and Preservation
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• v.13 no.3
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• pp.397-403
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• 2006

This experiment was conducted to examine the changes in polysaccharide concentration and morphological variation of Fomitopsis pinicola mycelium during submerged-culture in the citrus peel medium (CP). On the 12 days culture, the yields of mycelium and alcohol insoluble substance were 40.21%(w/v) and 6.94%(w/w), respectively, which were much higher than 11.29%(w/v, wet basis) and 3.17%(w/w, wet basis) obtained from YM medium. A large amount of acid soluble polysaccharides was derived from YM medium while a larger amount of alkali soluble polysaccharide was produced from CP medium. Yields of the mycelium were higher when cultured in CP medium However, there was no significant difference in formation of membranous vesicle between mycelia cultured in CP medium and YM medium. It was also observed that the formation of vacuole was closely related to the activation of the multivescular body known as cytolysome. As a result activation of mycelium and cell wall biosynthesis were more accelerated in CP medium.

• Food Science and Preservation
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• v.23 no.3
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• pp.341-346
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• 2016

The purpose of this study was to investigate alcohol content of commercial Korean fermented sources and to analyze the quality parameters such as titratable acidity, pH, salinity, reducing sugar, alcohol and yeast cell count. Eighty-seven samples of Doenjang, 68 samples of Kanjang and 57 samples of Kochujang were collected and divided into conventional and improved products depending on manufacturing method. As a result, the titratable acidities of conventional Doenjang, Kanjang and Kochujang were 1.72, 1.23 and 1.25%, and those of the improved products were 1.87, 1.80, and 1.00%, respectively. The pH values of conventional Doenjang and Kochujang were lower than those of the corresponding improved products and the pH of conventional Kanjang was higher than improved products. The salinities of the conventional products were higher than the improved products, and an the reducing sugar and alcohol content of the conventional products were lower than the improved products. The detection rate of alcohol (above 1%) in conventional Doenjang, Kanjang, and Kochujang were 6, 10 and 39%, respectively while the corresponding improved products showed much higher rates of 100, 76 and 100%, respectively. There was no significant difference in the yeast cell count between the alcohol-containing products and the alcohol-free products. Accordingly, further study is necessary to develop a manufacturing method using non-degradable sugar and salt control to reduce the production of alcohol in Korean source.

• Food Science and Preservation
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• v.19 no.1
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• pp.138-143
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• 2012

The anti-obesity activity of the $Cucubita$ $moschata$ Duch. extracts was investigated. The inhibitory effect on triglyceride accumulation was shown in 3T3-L1 preadipocyte. The lipid accumulation of the ethanol extract in 5 mg/mL concentration was shown to be 75.4%, where as that of water extract was shown to be 85.2%. The survival rate of the cell in the viability test was shown to be 86.5% in the 0.5-5 mg/mL concentration. Total polyphenol content was highest in the water extract($46.54{\pm}0.02$ mg). These results suggest that $Cucubita$ $moschata$ Duch. extracts have a potential as anti-obesity material by reducing the lipid accumulation.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.1
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• pp.45-53
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• 2009

Objectives: To determinate the optimal culture condition to maintain lifespan in human sperm, we evaluated the effect of different temperature on sperm motility and viability up to 5 days in normal specimens. Methods: Ejaculated semen samples with normal semen parameters were gently washed in HEPES buffered Tyrod's-Albumin-Lactate-Pyruvate (HTALP) media. Each 5 ml of HTALP + 0.3% albumin with $1{\times}10^6$ sperm/ml was incubated for 5 days in $37^{\circ}C$, $22^{\circ}C$, and $4^{\circ}C$. The sperm motility and kinematics were analyzed using computer assisted sperm analysis (CASA), membrane integrity was assessed by hypoosmotic swelling test (HOST), and capacitation status was evaluated by chlorotetracycline (CTC) fluorescence pattern. Each parameter was measured on day 1, 3, and 5, respectively. Results: The motility, viability and live/uncapacitated pattern were demonstrated significantly in temperature- and time-dependent difference (p<0.05). While the sperm cultured for 1 day in each temperature was not significantly different, the sperm cell kept in $22^{\circ}C$ after 3 days were preserved sperm motility, viability, membrane integrity, and F pattern better than in other culture temperatures. Conclusions: HTALP can be used a basic medium for culture and longevity preservation, and sperm cell kept at $22^{\circ}C$ is beneficial for assisted reproductive techniques.