• Journal of Environmental Health Sciences
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• v.42 no.4
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• pp.266-273
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• 2016

Objectives: This study evaluated the virucidal efficacy against avian influenza virus (AIV) of a disinfectant spray containing 0.25% grapefruit seed extract, 0.2% citric acid, 0.0625% malic acid and 0.0125% benzalkonium chloride. Methods: The disinfectant spray was diluted several times with hard water (HW) and organic matter (OM). Two point five mL of each diluent was added into each test tube, and 2.5 mL of AIV suspension was inserted into each test tube. After 30 minutes of virus-disinfectant contact reaction at $4^{\circ}C$, 2.5 mL of 10% inactivated fetal bovine serum was added into each test tube to neutralize the sanitizer efficacy. The neutralized solutions were serial 10-fold dilutions with phosphate buffer solution, and 0.2 mL of the diluents was injected into the allantoic cavity of five ten-day-old-chickens per dilution time. After incubation of the embryos for five days, the viability of the AIV was examined by hemagglutination titer. The valid dilution of the disinfectant spray was estimated according to the dilution time that the virus titer was inactivated more than $10^4$ 50% egg-infective dose (EID50)/mL compared with pathogen control. Results: In HW and OM conditions, the valid dilutions of the disinfectant spray against AIV were seven- and three-fold dilutions, respectively. The AIV titer of the pathogen control was more than 6.1 log10EID50/mL, and there was no embryonic toxicity. Conclusion: The present study showed that this disinfectant spray has effective virucidal activity against AIV.

• Journal of Food Hygiene and Safety
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• v.10 no.4
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• pp.263-270
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• 1995

In order to promote the prevention of microbial and enzymatic spoilage and to retain the freshiness, sweet persimmons harvested in Gyeongsangnam-do were treated with graperfruit seed extract(GFSE)-CaCO3 mixture and stored in the proper packaging conditions. A low concentration of GFSE showed effective growth inhibition of plant pathological bacteria and fungi, Enterobacter pyrinus and Fusarium sp., which were involved in the decay of fruits and vegetables. GFSE was stable to heat treatment; its antimicrobial activity was not changed by heat treatment upto 10$0^{\circ}C$. However, when the temperature was raised to 12$0^{\circ}C$, about 90% of total activity was retained within 30 min. GFSE was also highly stable to broad pH changes; its activity was not changed in the range of pH 2.0 to pH 12.0. The physiological function of cell membrane in the spores of Bacillus cereus and the hyphae of Fusarium sp. was destroyed by treating with GFSE. It was observed that treating sweet persimmons with GFSE minxture and storing them in strech-wrapped packages could prolong the greshness of sweet persimmons and reduce quality deterioration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.2
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• pp.315-321
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• 1994

In order to prevent the postharvest decay and to promote the freshness retention of fruits and vegetables grapefruit seed extract(GFSE), natural microorganism control agent, was applied to the preservation of fresh fruits and vegetables. Freshfruits and vegetables treated with GFSE and stored in polyethylene film (0.1mm) at 1$0^{\circ}C$-15$^{\circ}C$ of natural low temperature low kept better qualities in color and texture than the GFSE -not- treated control. The treatment using GFSE ina 250ppm to 500ppm concentration seemed to be an effective one for the control of Botrytis cinerea isolated in red wine grapes. After 4 weeks of storage the firmness rate of cucumbers treated with the dilute GFSE was four times higher than that of non-treated ones. GFSE showed effective inhibitory action towards plant pathological bacteria and fungi which were involved in the decay of fruits and vegetables. Minimum inhibitory concentrations of GFSE towards them were in the range of 250ppm to 500ppm .Direct visualization of microbial cells and spores using electron microscopy showed microbial cells and fungal spores the function of which was destroyed by treating with the dilute solutions of GFSE. It was observed that GFSE would reduced disease damages and have bactericide & fungicide properties during the storage of such fruits and vegetables as egg plant, wild edible greens , kumquat, and kiwi fruit.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.05a
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• pp.343-347
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• 2005

이 실험의 목적은 GSE 첨가가 간장과 고추장 양념액의 저장 조건에 따라 식중독균의 생육억제효과와 pH 변화를 조사하는데 있다. 저장 초기 비첨가구 경우에 간장 양념액의 pH는5.50, 고추장 양념액은 4.92 이였으며, GSE 첨가에 따른 양념액의 PH는 거의 변화가 없었다. 저장기간에 따라 pH는 고추장 양념액 보다 간장 양념액에서 서서히 낮아졌다. 식중독균의 생육억제효과는 우선 $20^{\circ}C$의 간장 양념액을 $4^{\circ}C$와 비교해 볼 때 GSE 농도에 따라 균수가 변화하는 반면 $4^{\circ}C$의 간장 양념액은 큰 변화가 없음을 알 수 있었다. 그러나 고추장 양념액의 경우는 온도와 GSE 농도에 따라 식중독균수의 차이가 나지 않았다.

• Journal of Life Science
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• v.19 no.1
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• pp.94-100
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• 2009

This study was carried out to examine the antimicrobial effects of grapefruit seed extract (GSE) and processed sulfur solution (PSS) against human skin pathogens: Malassezia furfur, M. restricta, Propionibacterium arnes, Trichophyton mentagrophytes and T. rubrum. The antimicrobial effects of GSE and PSS were tested by agar diffusion method and micro broth dilution method. As the results, the MIC values of GSE against M. furfur, M. restricta, P. acnes, T. mentagrophytes and T. rubrum were 3.91, 3.91, 0.004, 0.024, and $0.012{\mu}l/ml$, respectively. The MIC values of PSS were 0.03, 0.03, 0.156, 0.003, and $0.012{\mu}l/ml$, respectively. Antimicrobial activity of skin care emulsion products containing 0.5% GSE and 0.5% PSS against human skin pathogens were 5.2, 4.3, 8.0, 9.5 and 12.8 mm, respectively. Refractive index, pH, viscosity and color value of skin care emulsions containing GSE and PSS were measured. According to these results, it was concluded that the GSE and PSS were the promising sources of antibacterial agent which could be useful for skin and hair care products as well as for the alternative medicine development in treatment of certain types of skin ailments.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.141-148
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• 2005

This study was conducted to evaluate physicochemical and textural properties, and antimicrobial effects of low-fat comminuted sausages manufactured with sodium lactate $(3.3\%,\;SL)$ and various levels $(0.1\~0.3\%)$ of grapefruit seed extract (GSE, DF-100) during refrigerated storage for 10 weeks. Low-fat comminuted sausages (LFCS) has pH ranges of $6.09\~6.26,\;74\~76\%$ moisture, $<3\%\;fat,\;16\~17\%$ protein. The addition of SL $(3.3\%)$ and GSE with various levels $(0.1\~0.3\%)$ didn't impair water holding capacity (WHC), vacuum purge (VP) and Hunter color values (L, a, b). LFCS containing SL $(3.3\%)$ increased hardness and chewiness, whereas most TPA values were not affected by the addition of various levels $(0.1\~0.3\%)$ of GSE. LFCS containing $0.2\%\;or\;0.3\%$ GSE retarded the microbial growth of Listeria monocytogenes(LM). The addition of $0.3\%$ GSE in LFCS showed similar antimicrobial effect to $3.3\%$ SL, which kept $10^3 CFU/g$ until 10 weeks of refrigerated storage. Yellowness, VP and cohesiveness tended to be increased with increased storage time. These results indicated that the addition of $0.3\%$ GSE as a replacer for synthetic particularly paI1icuiarly inhibited the microbial growth of LM, resulting in antimicrobial effect similar to those of $3.3\%$ SL treatment without quality defects.

• Journal of Life Science
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• v.19 no.7
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• pp.956-962
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• 2009

The aim of this study was to assess the effects of dentifrice-contatning grapefruit seed extract (GSE) and processed sulfur solution (PSS) on antimicrobial effects against oral pathogens. We first evaluated the antimicrobial effects of GSE and PSS against oral microbes: Streptococcus mutans (Sm), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Candida albicans (Ca). When antimicrobial activity against Sm, Pi, Pg and Ca was tested, at 40 $\mu$l/disk, the inhibition zones of GSE were 11.0, 9.5, 8.0 and 9.0 mm, respectively. With the same method, the inhibition zones of PSS were 2.0, 3.5, 0.0 and 1.5 mm, respectively. In the micro broth dilution method, the MIC values of GSE against Sm, Pi, Pg and Ca were 0.24, 0.06, 0.10 and 15.63 $\mu$l/rnl, respectively. The MIC values of PSS were 0.12, 3.91,>125 and 7.81 $\mu$l/ml, respectively. When pH, refractive index, viscosity and color value of dentifrice-containing GSE and PSS were measured, there were no significant changes in these physical properties compared to the control samples. Antimicrobial activities of dentifrice products containing 0.5% GSE and 0.5% PSS against oral pathogens were 7.3, 4.3, 2.2 and 1.5 mm, respectively. According to these results, we conclude that there may be a role for GSE and PSS in the development of new oral supplies.

• Food Science and Preservation
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• v.16 no.4
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• pp.472-481
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• 2009

Response surface methodology (RSM) is frequently used for optimization studies. In the present work, RSM was used to determine the antimicrobial activitiesof grapefruit seed extract (GFSE) and a lactic acid mixture (LA) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, and Vibrio parahaemolyticus. A central composite design was used to investigate the effects of independent variables on dependent parameters. One set of antimicrobial preparations included mixtures of 1% (w/w) GFSE and 10% (w/w) LA, in which the relative proportions of component antimicrobials varied between 0 and 100%. In further experiments, the relative proportions were between 20% and 100%. Antimicrobial effects against various microorganisms were mathematically encoded for analysis. The codes are given in parentheses after the bacterial names, and were S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$). The optimum antimicrobial activity of the 1% (w/w) GFSE:10% (w/w) LA mixture against each microorganism was obtained by superimposing contour plots ofantimicrobial activities on measures of response obtained under various conditions. The optimum rangesfor maximum antimicrobial activity of a mixture with a ratio of 1:10 (by weight) GFSE and LA were 35.73:64.27 and 56.58:43.42 (v/v), and the optimum mixture ratio was 51.70-100%. Under the tested conditions (a ratio of 1% [w/w] GFSE to 10% [w/w] LA of 40:60, and a concentration of 1% [w/w] GFSE and 10% [w/w] LA, 70% of the highest value tested), and within optimum antimicrobial activity ranges, the antimicrobial activities of the 1% (w/w) GFSE:10% (w/w) LA mixture against S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$) were 24.55, 25.22, 20.20, 22.49, 23.89, and 28.04 mm, respectively. The predicted values at optimum conditions were similar to experimental values.

• Journal of Life Science
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• v.15 no.1 s.68
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• pp.66-70
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• 2005

In order to preserve the freshness of vegetables and to reduce the rate of decay, grapefruit seed extract (GFSE), a natural microorganism growth inhibiting agent, was applied during the preservation process of heat treated carrot and spinach. To investigate synergic effect of heat and GFSE treatment, carrots and spinaches were treated with or without 10 ppm of GFSE at $70^{\circ}C$. Surface color, texture and microbial counts of the samples were measured during storage at $4^{\circ}C$. GFSE showed an effective inhibitory activity against aerobic bacteria and yeast which might be involved in the decay of vegetables. Heat treatment at 2 min at $70^{\circ}C$ could also well preserve the color and texture of the vegetables. From the results, optimal concentrations of GFSE were 10 ppm and 50 ppm with heat treatment of 2 min $70^{\circ}C$ for the growth inhibitory effect to aerobic bacteria and yeast and preservation of color and texture.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.336-341
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• 2011

This study was carried out to investigate efficacy of aerosol sanitizer with natural antimicrobial and organic acids against Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes. The artificially inoculated pathogens on stainless steel coupon were treated with grapefruit seed extract (GFE), acetic acid, citric acid and lactic acid in model cabinet for 5 min. The number of three foodborne pathogens with individual treatment was reduced by 0.34-3.77 log units, treatment with GEF + organic acid was reduced by 1.72-3.89 log units and treatment with GEF + organic acid + alcohol was reduced by 1.46-5.05 log units. By treatment with GEF + lactic acid + alcohol in scale-up model system for 10 min. Populations of E. coli O157:H7, S. Typhimurium and L. monocytogenes were reduced by 3.42, 2.72 and 2.30 log units from the untreated control respectively. From the above result, aerosol sanitizer with natural antimicrobial agents and organic acid can be used as an environmental sanitation method with satisfying the consumer demand on safe food.