• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.33-39
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• 1995

The antibacterial and antifungal effect of grapefruit seed extract(GFSE) was investigated for its purpose of application to a diverse spectrum of field as sanitizers, disinfectants and preservatives. GFSE showed coparatively high content of such flavoniods as naringin and hesperidin and ascorbic acid. GFSE containing a low level of organic acids is a heavy viscous and water-soluble liquid. As a result of the antimicrobial test of GFSE, Bacillus subtilis and Aspergillus oryzae did not survive at detectable levels when treated with more than 100 ppm of GFSE. The minimum inhibitory concentrations of GFSE for a wide variety of pathogenic and putrefactive bacteria, fungi and yeasts were 100 ppm and 250 ppm, respectively. In the comparable electron micrograph of microbial cells treated with GFSE or not, we could conclude that GFSE destroy microorganisms by disrupting the functions of the cell wall membrane and microbial spores.

• Journal of Food Hygiene and Safety
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• v.7 no.1
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• pp.15-22
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• 1992

This study was conducted to determine the potential of grapefruit seed extract to support Aspergillus parasilicus growth and aflatoxin production. The grapefruit seed extract inhibited the growth and aflatoxin production of the fungi in the level of more than 4,000 ppm and 3,000 ppm in the medium, respectively. Grapefruit seed extract appears to block the conversion of acetate, averufin and versiconal acetate into aflatoxin in vitro experiments. The addition of grapefruit seed extract to the feeding experiment systems did not inhibit the incorporation of 14C-labeled versicolorin A, versicolorin A hemiacetal and sterigmatocystin into aflatoxin. In the electron microscopic examination the biocidal action of grapefruit seed extract was related to the disturbance of cell menbrane funtion, inhibiting cellular respiration.

• Food Science and Preservation
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• v.1 no.1
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• pp.1-7
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• 1994

To investigate the effect of several bactericides and fungicides against fruit & vegetable decay grapefruit seed extract(GFSE) was tested in a dilution solution. GFSE was shown to be effective against decay and rind breakdown and to extend the shelf-life of fruits and vegetables during storage and tiansport. Antimicrobial efficiency of GFSE on a wide spectra of gram + & - bacteria, moulds and yeasts was demonstrated by the measurement of minimal inhibitory concentrations performed (Bacteria 10-500ppm, Fungi:250-1,000ppm, Yeasts:100-250ppm). GFSE was separated and extracted into water-soluble fraction, water-insoluble and non-dialyzed fraction to isolate the antimicrobial substances. The water-soluble fraction showed the most active antimicrobial effect. The antimicrobial substances were isolated by gas chromatography. As the result of the isolation using GC, Peak-D was found to be the antimicrobial compound in GFSE. The identification of the most antimicrobial substance was carried out by using GC-MS.

• Food Science and Preservation
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• v.3 no.2
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• pp.187-193
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• 1996

To investigate the antimicrobial activities and effect of grapefruit seed extract(GFSE) on the physiological function of microorganism, antimicrobial activity, fatty acids of bacterial cell lipid and amino acids of bacterial cell protein were measured. The change of cell morphotype was observed by transmission electron microscope. GFSE was very stable on the wide range temperture and pH. The growth rate of E. coli and B. suvtilis were decreased above 40ppm GFSE There fore, minimum inhibitory concentration (MIC) of the E. coli and B. subtilis to GFSE were determined around 40ppm. In the change of fatty acids quantities, hexadecanoate was significantly decreased on the treatment compared with control in case of E. coli, whereas tridecanoate was not detected in case of B. subtilis. In the change of amino acids quantities, alanine, glutamic acid, glycine, lysine were decreased on the treatment compared with control in case of E. coli and B. subtilis Transmission electron microsgraphs(TEM) showed the microbial cells were destroyed by GFSE.

• Journal of Food Hygiene and Safety
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• v.6 no.1
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• pp.67-72
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• 1991

This study was carried out to investigate the preservative effect of grapefruit seed extract on fish meat product. he effect of GFSE has been tried on fish meat product divided into three lots; Control (no treatment), 500 ppm and 1,000 ppm of GFSE-treated samples. The results were summarized as follows; 1 During the storage of fish meat product, chagnges of crude protein contents of GFSEtreated samples were smaller than the control. 2 Texture was inclined to decrease as the storage period goes, the decrease ratio of GFSEtreated samples was smaller than the control. 3. SDS-PAGE patterns of fish meat product treated with or without GFSE showed that Mw 30,000-32,000 of major proteins were hydrolyzed and disappeared. The deterioration of fish meat product proteins occured in the storage period of 2 days in the control and 4-5 days in GFSE-treated samples. Conclusivery, the excellent preservative effects of GFSE on fish meat product were shown in the rheological, chemical test and sensory evaluation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.1
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• pp.30-34
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• 2000

Salted Chinese cabbage was washed in 1,000 ppm solutions of grapefruit seed extract(GFSE) or citric acid, and used to make kimchi for the retentio of quality characteristics during fermentation at $10^{\circ}C$. Kimchi treated with GFSE or citric acid showed a retarded increase in titratable acidity and decrease in pH and reducing sugar content. Total microbial count and lactic acid bacteria of GFSE treated kimchi were about 1.1 log(CFU/g) lower than those of control and citric acid treated kimchi after making, but the difference was gradually reduced during fermentation.

• Journal of Food Hygiene and Safety
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• v.9 no.3
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• pp.141-149
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• 1994

To investigate the distribution of Vibrio parahaemopyticus in the southern 4 coastal areas, Vibrio parahaemolyticus was isolated from seawater, shellfish and sediment from May to October in 1991, and antimicrobial effect of grapefruit seed extract (GFSE) on the growth of isolated strains were examined. In the 120 sample from 4 coastal areas, 16 strains of Vibrio parahaemolyticus were isolated and identified. The distribution serotype of isolated strains was 10 types of monovalent k-antiserum. Especially k-5 and k-28 were highly distribyted with 3 and 4 strains. 31.3% of isolated strains showed positive on Kanagawa phenomenon test. All isolated Vibrio parahaemolyticus were sensitive to chloramphenicol and gentamycin, 5 and 6 strains were resistant to streptomycin and colistin, respectively. Isolated strains were compared with geographical, month and sample. The distribution of 16 isolated Vibrio parahamolyticus was high at Hadong with 50%(8 strains), on July with 43.8%(7 strains) and from seawater with 37.5%(6 strains) respectively. Minimal inhibitory level of GFSE to Vibrio parahaemolyticus was 50 ppm. With 100 ppm treatment of GFSE, the destroy of cell membrane function, outflow of cell ingredients and ghost morphology of cell were investigated.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.297-302
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• 1990

This study was carried out to investigate the antimicrobial activity of the grapefruit seed extract (GFSE) The antimicrobial activity of GFSE was strong enough against such bacteria as Vibrio vulnificus, Vibrio fluvialis, Bacillus cereus, Staphylococcus aureus and Serratia sp. Growth of the above strains was inhibited by the GFSE'S concentration of 50 ppm. The growth of Vibrio vulnificus was completely inhibited by adding the 50 ppm GFSE to the nutrient broth medium with $3\%$ NaCl. The cell counts of Vibrio uulnfficus $5.2\times10^5$ at first in $5\%$ skim milk containing GFSE 0, 10, 30, 50 and 100 ppm were reduced to 35, 48, $5.6\times10^2,\;5.3\times10^3\;and\;9.6\times10^3/ml$ after 120 hours, respectively. And growth of Aspergillus Parasiticus, Asperillus versicolor, Penicillium funiculosum, Py-renochaeta terrestris and Trichoderma viride were inhibited by the concentration of GFSE 100, 50, 100, 10 and 30 ppm, respectively. The shelf life of Mulkimchi containing GFSE 50 and 100 ppm was 20 days longer than the control during storage at $5^{\circ}C\;and\;20^{\circ}C$.

• Food Science and Preservation
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• v.10 no.3
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• pp.288-292
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• 2003

Grapefruit seed extract powder (GFSEP), which was made with grapefruit seed extract and calcium carbonate, was investigated to retard the fermentation rate. The mixing ratios of GFSEP to salted Chinese cabbage were 0.1, 0.3 and 0.5％. Quality characteristics of kimchi such as pH, titratable acidity, reducing sugar content and microbial loads were measured during fermentation at 10$^{\circ}C$. pH and reducing sugar content of control and kimchi sample with 0.1％ GFSEP showed decreases until 10 days, and then attained to stabilized levels. Kimchi samples with 0.3％ and 0.5％ GFSEP maintained a higher pH and reducing sugar content, while microbial load was lower than others. Based on the pH and tit ratable acidity, kimchi samples with GFSEP prolong the shelf life about 3～10 days.