• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.815-822
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• 2005

In order to extend the shelf-life of packaged or coated foods, an antibacterial edible film was developed from soybean meal that had been fermented with Bacillus subtilis under the optimum condition of pH 7.0-7.5 and $33^{\circ}C$ for 33 h. The water vapor permeability of the fermented film ($86.0 mg/cm^2{\cdot}h$) was higher than those of normal soybean films ($66.9 mg/cm^2{\cdot}h$). Protein solubility of the fermented film was also higher than ordinary soy protein film at the pH range of 3 -10. The fermented soybean film had higher tensile strength and lower $\%$ elongation (elongation rate) than the ordinary soybean film, mainly because partial hydrolysis of proteins in the soybean film occurred during fermentation. Antimicrobial properties of the fermented film on foodstuffs were measured by placing the films on surime, jerked beef, and mashed sausage media; containing $10^2-10^3$ CFU/plate of foodborne pathogenic bacteria, and showed significantly higher inhibitory effects on the growths of all the indicating bacteria. The film could be used as a packaging material in the food industry. However, before direct application of the fermented film to the commercial food industry, its poor mechanical and antibacterial properties need to be improved.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1303-1309
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• 2004

In order to extend shelf-life of the packaged or coated foods, an antibacterial edible film was developed. Antimicrobial activities of 9 bacteriocin-like substance (BLS)­producing strains were evaluated after growing them on defatted soybean meal medium (DSMM). Bacillus subtilis was selected among those, because it showed the biggest inhibition zone against 6 problem bacteria in food. The antimicrobial edible film, containing $0.32\%$ of BLS, was produced from the fermented soybean meal with B. subtilis at the optimum condition of pH 7.0-7.5 and $33^{\circ}C$ for 33 h. The antimicrobial activity of the film was over $50\%$ of the maximum activity after film production with heat treatment at $90^{\circ}C$ and pH adjustment to 9. When the soy protein film with BLS was applied on the agar media containing E. coli, the growth inhibition was much higher than the ordinary soy protein film. These results indicate that the soy protein film with BLS from B. subtilis can be used as a new packaging material to extend the shelf-life of foods.

• 미생물학회지
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• 제49권3호
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• pp.286-291
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• 2013

한국인의 저염 섭취 필요성에 부응하기 위해 14% (w/w) 염도의 된장 대신 8% (w/w) 저염 된장을 제조하였다. 숙성 후 8% 저염 된장 시료들은 14% 염 된장과 달리 모두 산막을 형성하였고, 이 산막 형성균들을 동정한 결과 8종 모두 효모인 Pichia kudriavzevii에 속하였다. 장류 고유한 풍미를 유지하기 위해 발효 특성이 우수한 11종의 Bacillus 균들을 전통 장류에서 분리했고, 이들의 생화학적 특성 및 16S rRNA 염기 서열 분석 결과 B. subtilis, B. licheniformis, B. methylotrophicus로 동정되었다. 이 균주들은 8종의 산막 효모에 대해 증식 억제 능력을 보였으며, 항균 계면활성제인 lichenysin 또는 surfactin 유전자들을 함유하고 있었다.

• 한국식품과학회지
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• 제1권1호
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• pp.78-84
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• 1969

An attempt has been made to investigate the possible occurrence of aflatoxins, a group of micotoxin which are toxic metabolites produced by Aspergillus flavus, and aflatoxin like substances in fungal fermented soybean products such as meju and soybean paste. Chloroform extracts from 15 samples which has been defated with petroleum ether are subjected to separations with thin-layer chromatography on silica gel washed with methanol prior to film coating, improves the chromatographic separation and ultraviolet absorption spectral identification. In addition to fluorescencing spot having an Rf value which is same as aflatoxin $B_1$, many of the fluorescencing spots have been occurred in every sample examined. Each fluorescencing spot is scratched and the ethanol extracts are subjected to further separation with thin-layer chromatography. Each fluorescence substance is eluted with ultra violet transparent absolute ethanol and the ultraviolet absorption spectra are checked. None of the absorption curve of eluates shsow accordance with the curve of aflatoxin. 2, 4-Dinitrophenyl hydrazine reagent, Tollen's reagent and ninhydrin reagent are applied on the chromatogram- The data show that aflatoxin is not present in any of the fungal preparations examined.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1053-1059
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• 2006

The effectiveness of a proteinaceous fibrous material formed during commercial fermentation of soy protein (PFSP) and cysteine addition were evaluated in order to improve on the properties of soy protein-based films. Nine types of films were prepared at pH 7, 9, and 11, with heat treatments at $70^{\circ}C\;and\;90^{\circ}C$ for 30 min, by casting 5% (w/w) PFSP aqueous solution, containing 2.25% (w/w) glycerol, on to polystyrene plates. The tensile strength (TS) of films ranged from 3.88 to 6.87 MPa. The highest puncture strength (PS) was observed with pH 7.0 films prepared from PFSP solution heated at $70^{\circ}C$ (P<0.05). Alkaline pH and temperature caused a decrease in both the TS and PS of the films. The thickness of films ranged from $58\;to\;74{\mu}m$. Water vapor permeabilities of the films decreased with increasing pH and temperature. To produce films from PFSP, pH value of 7.0 to 9.0 and heat treatment of $70^{\circ}C\;to\;90^{\circ}C$ were needed. A soluble nature of PFSP films in water might be useful for preparation of hot water-soluble pouches. Cysteine addition could be necessary to produce films with increased TS and enhanced barrier properties. The combination treatment that provided the best combination of barrier and mechanical properties was the PFSP film prepared at pH 7.0 with addition of 1% cysteine. The films were good oxygen barriers.