• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.572-580
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• 2019

Recently, it has been reported that benzyl alcohol (BzOH) as an additive in cosmetics, food, and medicine lead to toxicity and allergy problem. Then, to circumvent this hurdle, we carried out the synthesis of benzyl alcohol galactoside (BzO-gal). Previously, it was confirmed that BzO-gal was synthesized by transgalactosylation reaction using Escherichia coli (E. coli) ${\beta}$-galactosidase (${\beta}-gal$). Meanwhile, in this study, two peaks of BzO-gal as sodium adduct ion (m/z=293.1004) and protonated ion (m/z=271.1180) were detected in the reaction mixture by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS). In addition, the amount of ${\beta}-gal$ and BzOH concentration, temperature, pH, and lactose concentration, respectively, were optimized (${\beta}-gal$, 0.75 U/mL; BzOH, 185 mM; temperature, $40^{\circ}C$, pH, 7.5; lactose, 350 g/l). Under these optimal conditions, 185 mM BzOH was converted into about 131 mM BzO-gal, in which the conversion yield was about 72%. In the future, BzO-gal will be applicable as a substitute for BzOH as a less toxic preservative for the cosmetic, pharmaceutical, and food industries, and we are planning to investigate the characteristics of BzO-gal as a preservative.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.9-15
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• 2012

This study analyzed the antibacterial activity of a Rubus coreanum (Bokbunja) ethanol extract. The antimicrobial activity was determined by disc diffusion, minimum inhibitory concentration (MIC), and growth inhibition methods with seven kinds of bacteria related to foodborne illness (Bacillus cereus, Escherichia coli, Escherichia coli O157:H7, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Salmonella typhimurium). In the results, disc diffusions of the ethanol extract from R. coreanum (9.8-17.5 mm at $4,000{\mu}g/disc$) clearly showed the antimicrobial activity of the extract against all tested microorganisms. Rubus coreanum promoted an inhibitory effect as follows: E. coli O157:H7 > P. aeruginosa > L. monocytogenes > E. coli > S. aureus > B. cereus ${\geq}$ S. typhimurium. In the MIC test, R. coreanum showed high antimicrobial effect against L. monocytogenes at 500 ppm. Moreover, the R. coreanum ethanol extract showed strong growth inhibition against microorganisms, similar to the MIC results. These results show that a R. coreanum ethanol extract has powerful antimicrobial activity against all tested microorganisms, suggesting that R. coreanum will be useful as a potential natural preservative.

• Journal of Food Hygiene and Safety
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• v.11 no.3
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• pp.203-207
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• 1996

One kind of fungus was isolated and identified from comtaminated red-ginseng in order to give fundermental data for improving hygienic quality of ginseng product. The isolated strain was identified as Aspergillus sp. Hyphae of the strain had septum structrue. The strain showed vesicle and sterigmata structure which were typical characteristics of Aspergillus species. The growth of the strain was slightly inhibited by sodium benzoate and potassium sorbate at a concentration of 0.05%. The strain showed no growth at 4.0% potassium sorbate. The isolated stain Aspergillus sp. showed no significant degradation in the presence of red-ginseng saponins.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1060-1077
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• 2021

Food additives are required to maintain the freshness and quality of foods, particularly meats. However, chemical additives may not be preferred by consumers, and natural materials with antimicrobial and antioxidant effects may be used as replacements for common chemical additives. Accordingly, in this study, we compared the antimicrobial and antioxidant activities of natural compounds extracted with ethanol and hot water, and emulsion sausage prepared with natural ethanol extracts was analyzed for pH, color, thiobarbituric acid reactive substances (TBARS), and Clostridium perfringens growth during storage. The antimicrobial activities of 49 natural extract candidates against Listeria monocytogenes, C. perfringens, Salmonella spp., and Escherichia coli were analyzed, and six natural materials with excellent antibacterial activities, i.e., Elaeagnus umbellata Thunb. f. nakaiana (Araki) H. Ohba, Punica granatum L., Ecklonia cava, Nelumbo nucifera Gaertner, and Schisandra chinensis (Turcz.) Baill., and Rubus coreanus Miq. were evaluated to determine their total polyphenol contents and DPPH radical scavenging activities. The total polyphenol contents of ethanol extracts were higher than those of hot water extracts, whereas DPPH radical scavenging activity was found to be higher in hot water extracts. The TBARS values of emulsion sausages were significantly increased as storage time increased, and the TBARS values of emulsion sausages prepared with natural extracts were lower than those of control sausages. Natural extract-treated emulsion sausages showed a 99% reduction in bacterial contents compared with untreated sausages on day 2, with greater than 99.9% reduction after day 3. Thus, these results demonstrated that natural extracts could have applications as natural preservatives in meat products.

• Korean Journal of Food Science and Technology
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• v.5 no.1
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• pp.49-54
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• 1973

Studies were carried out to investigate the relationship of the remaining percentage of antiseptics and the preservative effect of combined antiseptics and gamma radiation on the keeping quality of pork sausage. Antiseptics quantities, total bacterial counts, and pH were examined during the storage at $5^{\circ}C$ and $30^{\circ}C$. The results obtained were summarized as follows: 1) After irradiation, quantities of antiseptics decreased in proportion to the level of dosage and K-SOA showed more radiosensitivity than AF-2 (p<0.01). 2) The remaining percentage of antiseptics during storage were higher in samples of more irradiated and stored at the lower temperature. AF-2 decreased less than K-SOA. 3) The correlation between the increase of total bacteria counts and percentage of antiseptics survival in sausage was highly significant(p<0.01). High doses of irradiation, storage at lower temperature and use of AF-2, however, seemed to be effective in controlling the increase of total bacterial flora. 4) From the relationships among quantities of antiseptics, number of total bacteria and sensory evaluation, it was shown that the most suitable radiation dose was considered to be 0.5 Mrad, which was superior to 0.75 Mrad in keeping qualities and nonirradiation odor. 5) Effect of gamma ray on the heme pigments of sausage surface was not recognized.

• Korean journal of food and cookery science
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• v.25 no.3
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• pp.350-356
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• 2009

In order to develop a natural food preservative, UlGeum (Curcuma longa L.) powder was extracted with ethanol, and its antimicrobial activity was investigated. This ethanol extract showed antimicrobial activity against Bacillussubtilis, Escherichiacoli, and Staphylococcus aureus, and the resulting inhibition zones against the microorganisms by the extract (4 mg/disc) were 11, 10, and 8.5 mm, respectively. To test for further food preservation effects, solutions of the extract were added to rice cakes and noodles at concentrations of 0%, 0.25%, 0.50%, 0.75%, and 1.00%, respectively. Microbial growth was less in the UlGeum ethanol extract-added groups than in the control group. In sensory evaluations, there were significant differences among the groups of rice cakes and noodles in terms of color, taste, flavor, chewiness, and overall acceptability (p<0.05), and the 0.5% added groups received significantly higher scores than the other groups. Furthermore, as storage time increased, the sensory scores of the rice cakes and noodles significantly decreased in all groups (p<0.05). These results suggest that UlGeum is effective for increasing the shelf-life of rice cakes and noodles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1351-1357
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• 2016

Green tea (Camellia sinensis) seed extract (GTSE) was prepared under various pretreatment conditions and used to investigate its extraction yield and anti-yeast activity. Anti-yeast activity of GTSE from seeds with or without the coats was the same, whereas the extraction yield was slightly higher in extract from seeds without the coat. Anti-yeast activity of GTSE from seeds with different water contents or particle sizes was the same, whereas the extraction yield was highest in extract from seeds with 7.3% moisture or a smaller particle size. Anti-yeast activity of defatted green tea seed extract (DGTSE) was the same as that of GTSE. Extraction yield was higher in DGTSE from defatted seeds by the oil press machine compared to hexane extraction. Defatted green tea seed (DGTS), a by-product from the oil extraction process, is a good natural source of anti-yeast preservative. The extraction yield and anti-yeast activity of DGTSE were investigated using various extraction solvents, temperatures, and times. The results show that water was an economic extraction solvent, and anti-yeast activity of DGTSE was unstable at $90^{\circ}C$. These results suggest that water, extraction temperature of $50^{\circ}C$, and extraction time of 4 h were the most efficient for extraction of anti-yeast compounds from DGTS.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.2
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• pp.70-78
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• 1989

This experiment was carried out to develop the preparation method of chitosan which has strong antimicrobial activity, and also tried to investigate as a natural food preservative with this chitosan. The antimicrobial activity of chitosan was the strongest when deacetylation of chitin was conducted at $146^{\circ}C$ for 8 hours with $50\%$ sodium hydroxide. The growth of Escherichia coil was completely inhibited by adding this low molecular weight chitosan (M. W, 35,000) at the level of concentration of 75ppm to the medium. The antimicrobial activity was strong enough against such Gram positive bacteria as Staphylococcus sp. and Bacillus sp.. The growth of these strains was inhibited by the concentration of 50ppm but it was varied in its kinds against Gram negative bacteria. The concentration of chitosan re-quired for growth inhibition of microorganisms was 100ppm against Pseudomonas sp. and Vibrio sp., 2,000ppm against Salmonella sp.. The growth of Saccharomyces sp. was inhibited by the concentration of 100ppm, but Hansenula sp., Aspergillus sp., Penicillium sp. and Mu-cor sp. did not inhibited by even more than the concentration of 5,000ppm. The shelf life of Mulkimchi (pickle type Kimchi), containing $0.2\%$ chitosan was 10 days longer than control stored at $5^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.241-248
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• 2006

Conditions for extraction of antimicrobial materials from licorice root, Glycyrrhiza glabra, were optimized. Among solvents tested, 95% ethanol gave highest antimicrobial activity, and was chosen as optimal extracting solvent. Extraction temperature and time were optimal at room temperature and for 12 hr, respectively. Minimal inhibitory concentration (MIC) of 95% ethanol extracts was determined against 14 microorganisms. Reference microorganisms included 6 Gram(-) bacteria, 4 Gram(+) bacteria, and 4 yeast strains. Ethanol extract exerted very strong growth inhibition on Gram(+) bacteria, while was moderately effective for Gram(-) bacteria and yeasts. Treatment at $180^{\circ}C$ for 30 min or extreme pHs merely destroyed antimicrobial activity of ethanol extract. These findings suggest ethanol extract of G glabra may be useful as natural preservative.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.355-360
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• 2004

Residual contamination levels of natural microflora in strawberries were evaluated. Approximate counts of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were 8, 2, and 3 log CFU/g, respectively, whereas those of Escherichia coli and yeasts/molds were under the detection limit (<10 cells/g). Growth inhibition degrees of total aerobic mesophilic bacteria, total coliforms, and lactic acid bacteria were also evaluated based on three hurdles of preservative, storage temperature, and pH of strawberry paste prepared as model system. Strawberry paste was stored at low ($4^{\circ}C$), room ($20^{\circ}C$), and high ($37^{\circ}C$) temperatures. Potassium sorbate was added as a preservative up to 0.1%. Acidity of strawberry paste was adjusted to pH 4 or 7. During 7-day storage, inhibitory effects of the hurdles against bacterial groups were: storage temperature > pH of strawberry paste > addition of potassium sorbate. Combination of three hurdles most effectively inhibited growth of residual microflora.