• The Korean Journal of Food And Nutrition
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• v.36 no.6
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• pp.515-525
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• 2023

This research aimed to examine the effects of grapefruit seed extract (GSE) at various concentrations on the microbial safety and physicochemical characteristics of onion puree (0.01~0.1%). The onion puree was kept at 4℃ for 14 days. The results of the study indicated that the addition of GSE did not cause any significant changes in the sample's brix degree and viscosity in onion puree (p<0.05). However, as the concentration of GSE increased, the pH level decreased. On the other hand, as GSE was added, the lightness of the onion puree increased, while the redness and yellowness decreased. Compared to pure onion puree, the GSE-incorporated onion puree had higher levels of total flavonoid and total polyphenol content, indicating that it helps to maintain antioxidant activities. Based on the microbial safety test, aerobic bacteria, yeast, and mold were absent until day 14 of storage. In conclusion, the study suggests that the addition of GSE to onion puree increases its antioxidant activity and shelf-life.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.485-497
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• 2003

Grapefruit seed extract has been reported to have antimicrobial effect. The purpose of this study was to evaluate the antimicrobial and anti-gingivitis effect of chewing gum containing grapefruit seed extract and xylitol. 40 healthy subjects with gingivitis or early periodontitis were divided into two groups. Subjects in the experimental group chewed gum containing grapefruit seed extract and xylitol while subjects in the control group chewed gum containing only xylitol. All subjects received scaling and tooth brushing instruction. 1 week after scaling was set as baseline. Gingival index and plaque index were scored at baseline, 1 week, 2 week, 3 week and 4 week. Bleeding index, probing pocket depth and clinical attachment level were scored at baseline, 2 week and 4 week. The number of total bacteria and Streptococcus mutans in unstimulated saliva of experimental group were counted at 1 week, 2 week, 3 week and 4 week. Gingival indices of experimental group and control group at baseline, 1 week, 2 week, 3 week and 4 week were 0.850${\pm}$0.298, 0.575${\pm}$0.345, 0.533${\pm}$0.332, 0.459${\pm}$0.311, 0.408${\pm}$0.224 and 0.758${\pm}$0.379, 0.592${\pm}$0.276, 0.563${\pm}$0.281, 0.454${\pm}$0.194, 0.413${\pm}$0.199 (mean${\pm}$SD), respectively. Plaque indices of experimental group and control group at baseline, 1 week. 2 week, 3 week and 4 week were 0.497${\pm}$0.500, 0.375${\pm}$0.484, 0.332${\pm}$0.471, 0,286${\pm}$0.452, 0.210${\pm}$0.407 and 0.411${\pm}$0.492, 0.375${\pm}$0.484, 0.354${\pm}$0.479, 0.313${\pm}$0.463, 0.193${\pm}$0.395, respectively. Bleeding indices of experimental group and control group at baseline, 2 week and 4 week were 0.377${\pm}$0.177, 0.298${\pm}$0.152, 0.192${\pm}$0.108 and 0.383${\pm}$0.124, 0.318${\pm}$0.153, 0.225${\pm}$0.126, respectively. Probing pocket depth of experimental group and control group at baseline, 2 week and 4 week were 2.56${\pm}$1.00, 2.40${\pm}$0.65, 2.23${\pm}$0.64 and 2.45${\pm}$0.682.37${\pm}$0.57, 2.19${\pm}$0.57, respectively. Clinical attachment level of experimental group and control group at baseline, 2 week and 4 week were 2.58${\pm}$1.01, 2.43${\pm}$0.67, 2.26${\pm}$0.65 and 2.49${\pm}$0.70, 2.40${\pm}$0.59, 2.22${\pm}$0.62, respectively. The % of reduction of total bacteria in saliva of experimental group at 2 week, 3 week and 4 week were 46 ${\pm}$ 53%, 53 ${\pm}$ 5% and 69 ${\pm}$ 33%. The % of reduction of Streptococcus mutans count in saliva of experimental group at 2 week, 3 week and 4 week were 52${\pm}$69%, 88${\pm}$30% and 89${\pm}$17%. From these findings, it can be concluded that regular use of grapefruit seed extract /xylitol chewing gum may be effective to control and prevent gingivitis and may have caries-preventive effect.

• Food Science and Preservation
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• v.11 no.3
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• pp.411-416
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• 2004

Botanical antimicrobial agent-grapefruit seed extract mixture(BAAG), which could be applied to the preparation of antimicrobial packaging paper, was investigated in order to prove the preservative function of fruits and vegetables. HAAG showed remarkable antimicrobial effects against Fusarium solani Botrytis cinerea, Pencillium crustosum, Erwinia carotovora, Phoma destructiva and Alternaria radicina causing the postharvest decay of fruits and vegetables. We have examined that HAAG could inhibit the growth of microorganims when treated with more than 500 $\mu$g/mL concentration. The activities of HAAG were stable in the wide spectrum of pH and temperature. Direct visualization of microbial cells by using scanning electron microscope showed the loss of microbial cell membrane function, which was destroyed by treating with the dilute solutions of HAAG. We could confirm that HAAG be an antimicrobial agent for the preparation of antimicrobial packaging paper.

• Korean Journal of Food Science and Technology
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• v.35 no.2
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• pp.246-253
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• 2003

Application of xylitol (Xyl) and grapefruit seed extract (GSE) to improve the quality and preservation of baechu kimchi was attempted. Xylitol and grapefruit seed extract at various combinatory concentrations were added into baechu kimchi and fermented for 25 days at $10^{\circ}C$. Assay was performed on sensory value, acidity, and bacterial growth. Addition of 0.1% GSE and 2% Xyl showed the highest score in the overall acceptability, sour taste, and texture. Score of intensity characteristics in smell and sour taste were the highest in the control and that of texture the highest in 0.1% GSE plus 2% Xyl treatment. The pH decreased, and titratable acidity, and growth of total viable cells and lactic acid bacteria were remarkably retarded in 0.1% GSE plus 2% Xyl group compared to the control. Results showed that application of 2% Xyl plus 0.1% GSE to the kimchi fermentation enhanced sensory value of the fermented product and extended the storage period by about twofold.

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.614-618
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• 1991

To investigate the efficacy of grapefruit seed extract (GFSE) in the preservation of Satsuma mandarin, the citrus fruits were treated with 0 (control, only wash), 100 ppm and 250 ppm, dried and stored for 8 weeks at $15{\sim}20^{\circ}C$ and 60% RH. While 80% of the control fruits were contaminated and decayed by Penicillium sp., forming the the greenish blue spores, 27% of 100 ppm GFSE-treated fruits were contaminated and decayed and only 13% of 250 ppm GFSE-treated fruits were contaminated and decayed and only 13% of 250 ppm GFSE-treated samples were contaminated and not decayed by the fungi. GFSE showed marded inhibitory action against Penicillium sp. which was related to the decay of the citrus fruits in vitro experiments. Fungal growth was completely controlled through use of 500 ppm and the recommended range of GFSE to preserve the citrus fruits was $250{\sim}500ppm$. Transmission electron microscopic examination showed the fungal conidiospores the function of which was destroyed by dipping into GFSE.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.239-246
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• 2016

This study was performed to investigate changes in characteristics of Umbilicaria esculenta Yakju added with 0.5% and 1% grapefruit seed extracts (GSE) during storage for 75 days at $25^{\circ}C$ and 165 days at $4^{\circ}C$. Quality characteristics of pH, titratable acidity, turbidity, total aerobic microbes, and ethanol, glucose, acetic acid, and lactic acid contents were analyzed. Control group showed sharply increased pH, titratable acidity, turbidity, and acetic acid and lactic acid has contents while the 0.5% and 1% GSE groups added to Yakju did not show significant changes in pattern (P<0.05). Total aerobic microbes increased rapidly during storage from 15 days in the control group, and the 0.5% and 1% GSE groups showed gradually increased total aerobic microbes from 30 days of storage compared to the control group (P<0.05). In addition, in all test groups, coli, yeast, and fungus were not detected. Ethanol content slightly increased during storage and glucose content slightly decreased, but there were no large changes during storage between the control group and GSE groups. Therefore, 3 months and $4^{\circ}C$ are considered safe for 6 months of storage, and GSE is effective to improve shelf-life and quality improvement of Yakju.

• 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.

• Journal of Food Hygiene and Safety
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• v.9 no.4
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• pp.191-198
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• 1994

The major purpose of the present study is to syrvey vegetables, meats, seafoods, processed foods and imported foods for the presence of Listeria spp. and to prevent listeriosis caused by the contamination of Listeria monocytogenes. Listeria spp. was not found in vegetables and processed foods. The optimum growth condition of isolates indentified as Listeria monocytogenes was pH 7.0 and 37$^{\circ}C$. the antimicrobial effect of grapefruit seed extract(GFSE) was observed in the level of more than 100ppm by disk method. When 1ml(2.5$\times$106 CFU/ml) of Listeria monocytogenes was inoculated and incubated for 3 days at 3$0^{\circ}C$, the total cell number of the organism was 4.5$\times$109 in the control, 7.2$\times$103 in 100 $\mu\textrm{g}$/ml of GFSE medium, and 3.5 $\mu\textrm{g}$/ml of GFSE medium. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed microbial cell membrane the function of which was destroyed by treating with the dilute solutions of GFSE. It could be confirmed that GFSE completely inhibited the growth of the test strain of Listeria monocytogenes.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.370-374
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• 2008

The Gelidium corneum (GC)-whey protein isolate (WPI) blend film containing grapefruit seed extract (GSE) was prepared by incorporating different amounts (0, 0.02, 0.04, 0.08, 0.1%) of GSE into the film. The film's tensile strength (TS) and water vapor permeability (WVP) were improved by the addition of GSE. The film containing 0.1% GSE had a TS of 3.27 MPa, whereas the control had 2.64 MPa. WVP of the film was also significantly decreased by the addition of GSE. Addition of 0.1% GSE decreased the populations of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium by 1.0, 1.6, and 0.6 log CFU/g, respectively, compared to the control. Fish paste was packed with the GC-WPI blend film containing GSE, and microbial change in the fish paste inoculated with E. coli O157:H7, L. monocytogenes, and S. Typhimurium during storage was examined. Populations of E. coli O157:H7, L. monocytogenes, and S. Typhimurium were decreased by 0.60, 0.48, and 0.85 log CFU/g, after 7 day of storage, respectively. These results suggest packaging fish paste in the GC-WPI blend film containing GSE can extend the shelf life.