• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.35-41
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• 2006

Possible application of hurdle technology extention of shelf-life of fresh-cut apples was investigated by evaluating various hurdle factors known to be effective microbial growth inhibitors and their synergistic effects. Fresh-cut apples treated with chitooligosaccharide or grapefruit seed extract (GSE) showed higher microbial counts than those treated with distilled water during latter half of storage period, and at high concentrations. Citric and malic acids showed similar results, although microbial counts of fresh-cut apples treated with 0.75% or higher concentration of citric acid increased at 4 days of storage at $18^{\circ}C$, indicating malic acid is more effective than all hurdles tested for controlling microbial growth. Using ascorbic acid and calcium chloride as additional hurdles to control browning and softening, minimum and maximum compositions of dipping solution were: 0.25 : 0.5 : 0.25% and 0.75 : 1.0 : 0.75% malic acid: ascorbic acid: calcium chloride, respectively.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1189-1195
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• 2018

This study developed an antimicrobial hydrogel to control Listeria monocytogenes in Yukhoe (Korean beef tartare). Four hydrogels (hydrogel 1: 5% alginate+1% chitosan+0.2% $CaCl_2$, hydrogel 2: 1% ${\kappa}$-carrageenan+1% chitosan, hydrogel 3: 2% ${\kappa}$-carrageenan+1% $CaCl_2$, and hydrogel 4: 2% ${\kappa}$-carrageenan+3% $CaCl_2$) were prepared. The hydrogels then absorbed 0.1% grapefruit seed extract (GSE) and 0.1% citrus extract (CE) for 30, 60, 120, and 240 min to be antimicrobial hydrogels. To select the most effective antimicrobial hydrogel, their swelling ratio (SR) and antilisterial activities were determined. The selected hydrogel ($2{\times}2cm$) was then placed on surface of beef (round; $3{\times}3cm$), where L. monocytogenes (ca. $10^6CFU/g$) were inoculated, and the cell counts were enumerated on PALCAM agar. Among the hydrogels, the SR of hydrogel 1 increased with absorbing time, but other hydrogels showed no significant changes. Antimicrobial hydrogel 1 showed higher (p<0.05) antilisterial activity than other antimicrobial hydrogels, especially for the one absorbed the antimicrobial for 120 min. Thus, the antimicrobial hydrogel 1 absorbed antimicrobials for 120 min was applied on raw beef at $4^{\circ}C$, and reduced (p<0.05) more than 90% of L. monocytogenes on raw beef. These results indicate that antimicrobial hydrogel 1 formulated with 0.1% GSE or 0.1% CE is appropriate to improve the safety of Yukhoe by reducing psychrotrophic L. monocytogenes cell counts on raw beef.

• Journal of Korean Ophthalmic Optics Society
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• v.10 no.1
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• pp.63-69
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• 2005

The effects of R products of B company and natural disinfectant naringin, well-known chemical disinfectant on Corneal endothelium and epithelium of rabbit were observed by scanning electron microscope. The main component of naringin is extract of grapefruit seed, which is one of the flavonoid widely recognized as natural antioxidants and used as preservative agent of food and cosmetics. The chemical disinfectants cytotoxicity in cell cultures were announced by MIT assay and LDH leakage assay. But there has been no study about that chemical disinfectants and natural disinfectants is inserted drops on rabbit's cornea directly. In this test R products B company and natural disinfectants has been dropped on the cornea of rabbits for one weeks and observed cytotoxiciy by light camera after rose bengal staining. Also, we analysed the damage of corneal epithelium and endothelium morphologically after enucleating the cornea by scanning electron microscope.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.75-81
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• 2012

Molds cause severe cheese deterioration, even though some white and blue molds are used for the manufacture of Camembert and Blue cheese, respectively. The species of Geotrichum, Moniliella, Aspergillus, Penicillium, Mucor, Fusarium, Phoma, and Cladosporium are the main fungi that affect contamination during cheese ripening. Once deteriorated by fungal spoilage, cheese becomes toxic and inedible. Fungal deterioration of cheese decreases the nutritional value, flavor profiles, physicochemical and organoleptic properties, and increases toxicity and infectious disease. Fungal contamination during cheese ripening is highly damaging to cheese production in Korean farmstead milk processing companies. Therefore, these companies hesitate to develop natural and ripened cheese varieties. This article discusses the recent and ongoing developments in the removal techniques of fungal contamination during cheese ripening. There are 2 categories of antifungal agents: chemical and natural. Major chemical agents are preservatives (propionic acid, sodium propionate, and calcium propionate) and ethanol. Among the natural agents, grapefruit seed extract, phytoncide, essential oils, and garlic have been investigated as natural antifungal agents. Additionally, some studies have shown that antibiotics such as natamycin and Delvocid$^{(R)}$, have antifungal activities for cheese contaminated with fungi. Microbial resources such as probiotic lactic acid bacteria, Propionibacterium, lactic acid bacteria from Kimchi, and bacteriocin are well known as antifungal agents. In addition, ozonization treatment has been reported to inhibit the growth activity of cheese-contaminating fungi.

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.584-589
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• 2000

In order to inhibit rot of soybean sprouts, presoaking treatments of soybeans with various solutions were studied. Optimal soaking time was 20min and citric acid, chitosan, GFSE(Grapefruit seed extract) were more effective. Most of presoaking treatments decreased the rot ratio of soybeans considerably, and didn't decrease germination ratio of them compared to control. Particularly GFSE, chitosan and phosphate buffer were effective. Presoaking treatments besides ethanol showed increased weight and yield of soybean sprouts compared to control, and particularly chitosan treatment increased yield of 67%, weight of 6.9% and length of 9.5% of soybean sprouts compared to control. Presoaking treatments decreased total microbial count of soybeans and rot of soybean sprouts during cultivation.

• Journal of the Korean Dietetic Association
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• v.24 no.4
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• pp.330-343
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• 2018

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at $50^{\circ}C{\sim}95^{\circ}C$ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.25 no.3
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• pp.87-99
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• 1999

Manuka oil named New Zealand’s tea tree oil is oil-soluble and comes firom nature. Manuka oil and its extract $\alpha$-pinene, Oxy’less clear, R-limonene which is one of the component of Citron extracted from Grapefruit seed and Citrex were used to estimate the antimicrobial activity and to improve the capability of antiseptic. Disk diffusion method was used to measure the antimicrobial activity. Escherichia coli which is gram-negative bacteria and Staphylococcus aureus which is gram-positive bacteria were used as strain. The antimicrobial activity of Manuka oil and $\alpha$-pinene for Escherichia coli, Staphylococcus aureus was similar when the concentration of Manuka oil and $\alpha$-pinene are 10u/paper disk. However, antimi-crobial activity of Manuka oil fDr Escherichia coli, Staphylococcus aurem was better than that of $\alpha$-pinene when the concentration of Manuka oil and $\alpha$-pinene was low. Antimicrobial activity of Oxy’less clear is better than that of propyl para hydroxybenzoate(PPHB), R-limonene at all the concentration and is similar to that of $\alpha$-pinene. Antimicrobial activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1381-1384
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• 2004

In order to help the preservation of the cherry tomatoes, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to packaging fruits. The fruits were packed with a paper bag of 15.5${\times}$24 cm and then stored at 1$0^{\circ}C$. During the storage, weight loss, pH, total acidity, soluble solid content, microbial load and decay were measured as quality indices. Steady weight loss due to the transpiration was observed to slightly increase the solid content during the storage with little difference between the packaging treatments. There were little change in pH and acidity of the stored fruits. The microbial loads of total aerobic bacteria, and yeast/mold counts were significantly suppressed during 10 day storage by the antimicrobial paper packaging, which also contributed to reducing the decayed fruits observed after 15 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.10
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• pp.1715-1719
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• 2004

In order to help the preservation of the unshiu orange and pear, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to pack fruits. Unshiu orange was packed in a box (24${\times}$24${\times}$22 cm) attached with antimicrobial paper and then stored respectively at l$0^{\circ}C$. Pears were wrapped individually before storage at l$0^{\circ}C$. During the storage, weight loss, pH, total acidity, soluble solid content, microbial load and decay were measured as quality indices. Steady pH increase in unshiu orange was observed to slightly decrease total acidity during the storage with little difference between the packaging treatments. The microbial loads of total aerobic bacteria, and yeast/mold counts were suppressed during storage by the antimicrobial paper packaging, which also contributed to reducing the decayed unshiu orange. Limited reduction of total aerobic bacteria and yeast/mold counts was observed only for initial storage period for the pears wrapped with 9 and 12% antimicrobial agent-added papers. Antimicrobial paper was useful for the reduction of microbial load in unshiu orange and pear without other quality deterioration.

• Food Science and Preservation
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• v.13 no.3
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• pp.273-278
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• 2006

In order to help the preservation of the cherry tomato and unshiu orange, antimicrobial paper incorporating grapefruit seed extract and zeolite was applied to the package. Cherry tomato and unshiu orange were packed in a box (38x25x20 cm) attached with antimicrobial paper and then stored respectively at $5^{\circ}C$. During the storage, weight loss, pH total acidity, soluble solid content microbial load and decay ratio were measured as quality indices. pH increase in cherry tomato was observed until 20 days, and decreased with litle difference between the packaging treatments thereafter pH and total acidity decrease in unshiu orange were shown till 30 days, and abrupt change was revealed by 40 days. This was due to physiological disorders. The microbial loads of total aerobic bacteria, and yeast/mold count were suppressed during storage by the box packaging incorporated with antimicrobial agents, which also contributed to reducing the decayed cherry tomato and unshiu orange. Antimicrobial paper was useful fur the reduction of microbial load in cherry tomato and unshiu orange pear without other quality deterioration.