• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1466-1470
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• 2009

This study was focused on the development of anticariogenic edible films using pullulan containing grapefruit seed extract (GFSE), polylysine or propolis. According to the result of antimicrobial activity (disc diffusion method) of GFSE, polylysine and propolis against Streptococcus mutans, antimicrobial pullulan film was produced by adding grapefruit seed extract. The optimum combination of pullulan and sorbitol (plasticizer) was 10$\sim$15% (w/v) and 40$\sim$50% of pullulan (w/w), respectively. Minimum concentration of grapefruit seed extract for growth inhibition of Str. mutans was 50 ppm in medium. Formulation of antimicrobial pullulan films containing grape seed extract was established and these results evidently showed potential for commercial application.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.289-296
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• 1990

The antimicrobial and antioxidant activities of grapefruit seed extract(GFSE), which was extracted with glycerine in the special schematic extraction apparatus, were investigated for handling and processing of fishery products. The effectivity of GFSE has been tried on sardine, mackerel and shrimp divided into six lots for each fishery product: control(no treatment) and five GFSE-treated samples. Samples were inoculated with Salmenella typhi, incubated for 24hrs at $30^{\circ}C$ in dextrose-tryptone broth medium and prepared for microbiological 8f chemical analysis and organoleptic assessment. The bacteriological analytical results with GFSE(250ppm) showed the reduction of $1.8\times10^6\to2.0\times10^4,\;1.9\times10^6\to1.8\times10^4$ and $1.6\times10^6\to2.7\times10^3$ in total bacterial count for sardine, mackerel and shrimp, respectively. The test results with GFSE(500ppm) showed a $100\%$ reduction of bacterial mackerel treated with GFSE(500ppm) was reduced to $1.1\times10^4$ and $9.0\times10^3$ respectively. Antioxidant effect of treatment with GFSE at 500ppm level for three products was significant. LSD test results on organoleptic parameter for the samples treated with various showed a significant influence on the appearance, odor and texture in which at concentration 500ppm level give the excellent scours compared to each control.

• 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.

• 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.

• Food Science and Preservation
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• v.7 no.1
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• pp.8-11
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• 2000

The antimicrobial extracts of rheum palmatum and coptis chinensis root as well as grapefruit seed extract(GFSE) were applied to dipping treatment for keeping qualities of cucumbers, respectively, which were then packed in low density polyethylene(LDPE) films incorporated with 1 % antimicrobial extracts and stored $10^{\circ}C$. Dipping and packaging in the antimicrobial agents suppressed the growth of putrefactive microorgani는 and the decay ratio of cucumbers. In addition, the loss ratio of ascortic acid content and their weight was decreased during the sotrage of cucumbers. Consequently, the combined method of dippinf and packaging in antimicrobial agents turned out to be superior to dipping treatment or film-packaging in the view point of decay ratio and the keeping qualities of cucumbers.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.99-106
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• 1992

To prevent food-poisoning outbreaks by Vibrio vulnificus the antimicrobial efficacy of grapefruit seed extract (GFSE) was examined. Minimal inhibitory concentration (in vitro) for the microorganism was found to be 50∼100 ppm. Transmission electron micrographs of Vibrio vulnificus showed the biocidal action of this natural antimicrobial agent would be related to specific respiratory effect coupled with the destruction of permeable function of microbial cell membrane. After Anguilla japonica GFSE-injected to the body was incubated in the seawater contaminated by Vibrio vulnifiucs the fish meats were taken up, mixed with control diet and used as a diet in the feeding experiment. In this experiment the effect of GFSE treated with fish muscle on body weight, protein efficiency ratio, serum enzymes and serum blood components of broiler chicks was investigated. It is proved from this study that there is neither Vibriosis nor toxicity associated with GFSE itself an fish meats treated with it when it is injected to the fish body at a level of 250 ppm or less.

• Food Science and Preservation
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• v.6 no.1
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• pp.43-47
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• 1999

To develop a wrapping film, which suppresses the microbial decay through the storage and distribute of greenhouse fresh produce, the antimicrobial packaging films were made and applied to the preservation of grapes(Campbell early). For the purpose the films were made by adding 1% grapefruit seed extract(GFSE) to LDPE film(Control). Graps were separately wrapped with packaging films in the state of closely-adhered packaging as well as modified atmosphere packaging(MAP). The wrapped grapes were stored at 5$^{\circ}C$ for 65 days and then the colony count of contaminated microorganims, decay ration of grapes, the gas component within the packages and chemical qualities were investigated. The antimicrobial film packaging showed the efficient results to suppress microbial growth as compared with control. The total number of containated microorganisms were decreased gradually through all the storage period. In the closely-adhered packaging and MAP the decay ratios of grapes was 31% and 19%, indivisually. After the storage period of 65 days, the interior gas components of MAP were 4.5% of O2 and 17.6% of CO2, which were efficient for the storage of grapes. In addition, no negative effects in sweetness and acidities occurred.

• Food Science and Preservation
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• v.8 no.3
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• pp.264-268
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• 2001

Two antimicrobial extracts of Rheum palmatum L. and Coptis chinesis France root as well as grapefruit seed extract(GFSE) were applied to dipping treatment for green chilli peppers, which were then packed in low density polyethylene(LDPE) films incorporated with 1% antimicrobial extracts and stored 10$^{\circ}C$. Dipping and packaging treatments suppressed the growth of putrefactive microorganisms and the duly ratio of green chilli peppers. In addition, the loss ratio of ascorbic acid content and their weight during the storage was lower with treated green chilli peppers. Consequently, the combined method of dipping and packaging in antimicrobial agents turned out to be superior to dipping treatment or film-packaging in the view point of decay ratio and the keeping qualities of green chilli peppers.

• Food Science and Preservation
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• v.10 no.1
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• pp.37-40
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• 2003

Coptis chinensis extract and grapefruit seed extract, natural antimicrobial substances, were applied to the dipping treatment of strawberry and incorporated in the packaging films. Strawberry was steeped in the extract solutions of 50 ppm concentration and packed with the low density polyethylene(LDPE) films incorporated with 1% extracts. During the storage at 5$^{\circ}C$, the qualities of microbial counts, awぶy ratio, texture and chemical attributes were measured for the pretreated strawberry. The LDPE films incorporated with the extracts retarded the growth of aerobic bacteria, lactic acid bacteria and yeast that had been contaminated before the pretreatment, significantly lowed the decay ratio, and gave better retention of textural firmness. The chemical and physical qualities of strawberry were not affected by the packaging films. When strawberry was steeped in the extract solutions, the effects of the packaging film incorporated with the extracts on the qualities of strawberry were accelerated.

• 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.