• Journal of the Korean Society of Food Culture
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• v.15 no.1
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• pp.9-15
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• 2000

This study was conducted to investigate the antimicrobial activity of grapefruit extracts and polylysine mixture against food-borne pathogens. The mixture was showed a potent and quick antibacterial activity for 5 major bacteria causing food poisoning i.e. Escherichia coli, Escherichia coli O-157, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae. The antibacterial effect of the mixture on the ordinary bacteria inhibiting on the surface of lettuce was lasted even 6 hrs after the treatment, however the mixture was non-effective on the color, smell and taste of lettuce. The treatment with 10% mixture solution of the foods such as fish, meat, rice and bread suppressed the growth of the bacteria and kept the foods more freshly than the untreated foods.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.109-113
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• 2000

Somatic hybrids were produced by electrofusion between embryogenic callus protoplasts of 'Syougun' mandarin and leaf protoplasts of grapefruit. Hybridity of the two plants was confirmed by leaf morphological characteristics and random amplified polymorphic DNA (RAPD) analysis. The cpDNA analysis using PCR-RFLP could not distinguish those of both parents. These plants showed normal growth and had chromosome number of 27. These unexpected triploid somatic hybrids might be derived from fused cells between diaploid protoplast of embryogenic calli and diploid protoplast of leaf, because polysomaty, a mixture of haploid cells and diploid cells was observed in the lactose medium-pretreated embryogenic calli of 'Syougun' by flow cytomehy analysis.

• 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 Microbiology and Biotechnology
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• v.30 no.12
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• pp.1854-1861
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• 2020

Staphylococcus aureus is one of the most common microorganisms and causes foodborne diseases. In particular, biofilm-forming S. aureus is more resistant to antimicrobial agents and sanitizing treatments than planktonic cells. Therefore, this study aimed to investigate the anti-biofilm effects of cell-free supernatant (CFS) of Saccharomyces cerevisiae isolated from cucumber jangajji compared to grapefruit seed extract (GSE). CFS and GSE inhibited and degraded S. aureus biofilms. The adhesion ability, auto-aggregation, and exopolysaccharide production of CFS-treated S. aureus, compared to those of the control, were significantly decreased. Moreover, biofilm-related gene expression was altered upon CFS treatment. Scanning electron microscopy images confirmed that CFS exerted anti-biofilm effects against S. aureus. Therefore, these results suggest that S. cerevisiae CFS has anti-biofilm potential against S. aureus strains.

• Safe Food
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• v.3 no.3
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• pp.23-31
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• 2008

• Korean Journal of Plant Resources
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• v.32 no.6
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• pp.633-643
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• 2019

Long-term ultraviolet (UV) exposure accelerates the phenomenon of skin photo-aging by activating collagenase and elastase. In this study, we aimed to investigate the effects of a combination of grapefruit and rosemary extracts (cG&Re) on UVB-irradiated damage in HaCaT cells and dorsal mouse skin. In HaCaT cells, cG&Re recovered UVB-reduced cell viability and inhibited protein expression of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinases (p-Erk), c-Jun N-terminal kinases (p-JNK), and a class of MAPKs (p-P38). Also, cG&Re suppressed UVB-induced collagen and elastin degradation by decreasing matrix metalloproteinases (MMPs) and nuclear factor kappa light chain enhancer of activated B cells (NF-κB) expression, which is a transcription factor. Similar results were observed in dorsal mouse skin. Taken together, our data indicate that cG&Re prevent UVB-induced skin photo-aging due to collagen/elastin degradation via activation of MAPKs, MMPs, and the NF-κB signaling pathway in vitro and in vivo.

• KSBB Journal
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• v.29 no.3
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• pp.145-154
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• 2014

A fresh vegetable and fruit juice has become a new healthy food available for detoxification, dieting and health. This paper presents the useful information about the quality changes of fresh juice according to different juicer. Quality of fresh juice could be evaluated by several factors such as juice yield, enzyme activity, antioxidant activity, polyphenol contents, and anti-inflammatory activity. The juice yields of 12 different vegetables and fruits were compared using 6 different juicers and it was observed that the yield of slow juicer was better than that of conventional blender. Among 12 samples, the juice yield of grape is the best and the pH of the juice was in the acidic range of 3 and 4. Kiwi and grapefruit were the best in terms of protease enzyme activities by Hemoglobin units on the tyrosine basis and Spectrophotometric acid protease unit and papain units on the tyrosine basis of KFDA protocols. The total polyphenol contents were also high in kiwi and grapefruit. The antioxidant activity by diphenyl-1-picrylhydrazyl (DPPH), superoxide dismutase (SOD), and radical scavenging assay were high in the order of kiwi, grapefruit, grape, tomato, and orange. Anti-inflammatory activities were also assay for 12 samples with 6 juicers. It can be concluded that of fresh fruit and vegetable juice provides a source of antioxidant components and enzymes with high activity. And the enzyme activities could be used as one of the quality indicator of fresh juice. Concerning the juicers used in this study, slow juicer could be recommended to prepare the fresh juice in terms of the juice quality.

• Journal of Life Science
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• v.20 no.8
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• pp.1230-1234
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• 2010

The effects of inhaling three essential oils (lavender [Lavendular angustifolia], silver fir [Abies alba], and grapefruit [Citrus paradise]) against restraint stress were investigated in mice. Serum cortisol levels were significantly increased in the 1h-restraint group. Also, silver fir and grapefruit oils prevented the elevation of cortisol levels under experimental conditions. Inhalation of 10% lavender oil for 30 min before inducing stress significantly inhibited restraint-induced hypothermia. We also investigated the effects of restraint stress on triglycerides, total cholesterol, and high-density lipoprotein cholesterol. It was found that the concentration of triglycerides in the serum samples increased after restraint stress. Silver fir essential oil inhibited elevation of triglyceride levels. Taken all together, the correlation of herb essential oil inhalation against restraint stress in animals can partly be explained.

• Food Science of Animal Resources
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• v.37 no.3
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• pp.429-439
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• 2017

This study investigated the antioxidative and functional effects of a curing agent containing grapefruit seed extract (GSE) on the quality and storage characteristics of chicken breast. The total polyphenol and total flavonoid contents of GSE were 45.06 mg/g and 36.06 mg/g, respectively. The $IC_{50}$ value of 2,2-diphenyl-1-picrylhydrazyl hydroxyl scavenging of GSE was $333.33{\mu}g/mL$. The chicken breast comprised six groups: no-treatment (N), 0.2% ascorbic acid + 70 ppm sodium nitrite (C), 0.05% GSE (G0.05), 0.1% GSE (G0.1), 0.3% GSE (G0.3), and 0.5% GSE (G0.5). The pH and cooking loss of cured chicken breast decreased with increasing GSE levels, and the water holding capacity increased with increasing GSE levels. The hardness and chewiness of GSE-treated chicken breast were higher than those of N and C. Hunter's L and a color values increased significantly after GSE addition. Moreover, 0.1% GSE (G0.1) increased the flavor and total acceptability scores. The 2-thiobarbituric acid and volatile basic nitrogen values of the 0.5% GSE group decreased significantly compared with those of C group. Total microbial counts of GSE-treated chicken breast were higher than those of C, but that lower than those of N. Adding GSE to chicken breast delayed lipid peroxidation and had antimicrobial effects during cold storage. GSE improved shelf life and palatability; therefore, it could be used as a natural antioxidant and functional curing agent ingredient in meat products.

• Food Science and Preservation
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• v.16 no.1
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• pp.134-137
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• 2009

The gelatin film containing grapefruit seed extract (GSE) was prepared by incorporating different amounts (0, 0.02, 0.05, 0.08, 0.1%) of GSE into the film. The tensile strength (TS) of the film increased by the addition of GSE, and water vapor permeability (WVP) of the film decreased. In particular, the gelatin film containing 0.1% GSE had a TS of 10.28 MPa, while the control had 8.68 MPa. WVP of the film containing 0.1% GSE decreased to 2.18 ng m/m2 s Pa, compared to 2.48 ng $m/m^{2}s$ Pa of the control. In addition, incorporation of 0.1% GSE to the gelatin film decreased the populations of Escherichia coli O157:H7 and Listeria monocytogenes by 2.67 and 3.15 log CFU/g, respectively, compared to the control. These results suggest that as a packaging material, gelatin film containing GSE can have antimicrobial activity against pathogenic microorganisms in foods.