• Title/Summary/Keyword: microbiological properties

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Improvement of Kimchi Fermentation by Using Acid-Tolerant Mutant of Leuconostoc mesenteroides and Aromatic Yeast Saccharomyces fermentati as Starters

  • Kim, Young-Chan;Jung, Eun-Youg;Kim, Hyung-Joo;Jung, Dai-Hyun;Hong, Seong-Gil;Kwon, Tae-Jong;Kang, Sang-Mo
    • Journal of Microbiology and Biotechnology
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    • v.9 no.1
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    • pp.22-31
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    • 1999
  • Saccharomyces fermentati and Leuconostoc mesenteroides were isolated from a traditional kimchi, and then the Leu. mesenteroides was mutated to the acid-tolerant mutant Leu. mesenteroides M-l00. In the result of growth properties in MRS broth with various pHs adjusted with HCl and acid solution (latic acid:acetic acid=1:2), an acid-tolerant mutant Leu. mesenteroides M-100 showed more increased ability for growth than its wild strain at various temperatures. The strains were used as starters for the fermentation of kimchi. The experiments were performed with classified experimental groups (Group I, control kimchi; Group II, addition of YK-19 only; Group III, addition of M-100 only; Group IV, addition of mixture of M-100 and YK-19), and their pH, total acidity, reducing sugars content, organic acid productivity, organoleptic tests, and microfloral changes were compared. As a result, in pH and acidity, the optimal ripening period of Group IV was about 13.5 days (i.e. from the 8.5 to 22 days of fermentation). This result indicates that the optimal ripening period of Group IV was about 1.5 times longer than that of Group I. Furthermore, Group IV was edible to 28 days of fermentation. In addition, high contents of succinc acid was observed in Group IV. Group IV was also highly ranked on the organoleptic test. During the fermentation of kimchi, the number of Leuconostoc sp. in group I reduced after 7 days; however, the number of Leuconostoc sp. in Group II, III, and IV decresed after 14 days of fermentation. An especially high number of Leu. sp. was observed in Group IV, and this gave better flavor of kimchi than any other during the whole fermentation period. Citric acid, tartaric acid, succinic acid, fumaric acid, and lactic acid were detected in the kimchi, and a significant increase in the concentration of lactic acid during fermentation was observed in the all experimental groups.

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Reactive Dyeing Properties of Cotton/hemp Blend

  • Lee, Ji-Eun;Kim, Sung-Eun;Kim, Hyung-Sup;Kim, Hyung-Joo;Koh, Joon-Seok
    • Textile Coloration and Finishing
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    • v.21 no.5
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    • pp.10-15
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    • 2009
  • A mixed bi-functional reactive dye has been applied to the cotton and the cotton/hemp blend and their dyeing and fastness properties were compared. The cotton/hemp blend exhibited higher exhaustion values and better build-up property than cotton, presumably due to the lower crystallinity. Hence, the reproducibility of dyeing of hemp is expected to be excellent. Fastness properties of reactive dyes on cotton and cotton/hemp blend are found to be almost identical. The results obtained suggest that hemp in cellulosic fabric could be used as an important alternative to universal cotton in cellulose fabrics.

Chitinase from an Antarctic Bacterium, Sanguibacter sp. KCTC10714

  • Lee, Hong-Kum
    • Proceedings of the Microbiological Society of Korea Conference
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    • 2006.05a
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    • pp.97-99
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    • 2006
  • A chitinase-producing bacterium strain KCTC10714 was isolated from sea sand around the King Sejong Station, King George Island in Antarctica. It was identified as Sanguibacter sp., based on the biochemical properties and 16S rRNA gene sequence. KCTC10714 chitinase showed enzyme activity in broad range of temperature from 0 to $70^{\circ}C$. At $0^{\circ}C$, it showed 70.9% of relative activity in comparison with 100%. The chitinase gene of KCTC10714 was cloned using inverse PCR cloning method. KCTC10714 chitinase gene was designated as chi21702. The ORF of chi21702 consisted of 1,449 bp (482 amino acid), and contained ChtBD3 (a chitin/cellulose binding domain) and an active site for chitinase family 18.

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Properties of a bilirubin oxidase from Penicillium sp. LAM 91-89 (Penicillium sp. LAM 91-89가 생산하는 bilirubin oxidase의 특성)

  • Yi, Dong-Heui;Lee, Dong-Ho;Kim, Jung-Bae;Lee, No-Woon
    • Applied Biological Chemistry
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    • v.36 no.3
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    • pp.158-162
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    • 1993
  • A bilirubin oxidase produced by Penicillium sp. strain LAM 91-89 was purified and partially characterized. The enzyme was purified about 70 folds from culture broth by ethanol precipitation, first and second Sephadex G-200 column chromatography with overall yield of 12%. The molecular weight of the enzyme was estimated to be 53,000 dalton by SDS-PAGE. The optimum pH and temperature was 8.5 and $40^{\circ}C$, respectively. The enzyme was stable in the pH range $6{\sim}10$ and below $40^{\circ}C$. Activity of the enzyme was increased by the addition of $Mg^{2+}$ but was gretly inhibited by $Ag^+,\;Hg^{2+},\;Mn^{2+},\;Pb^{2+}$, iodoacetate, p-chloromercurobenzoic acid and sodium dodecyl sulfate. Among various substrates, bilirubin was favorably reacted and $K_m$ value for bilirubin was $6.67\;{\mu}mole$.

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Microbiological, Physicochemical, and Antioxidant Properties of Plain Yogurt and Soy Yogurt (플레인 요구르트와 소이 요구르트의 미생물학적, 물리화학적 및 항산화 활성)

  • Lim, Sung-Mee
    • Korean Journal of Microbiology
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    • v.49 no.4
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    • pp.403-414
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    • 2013
  • This study evaluated the physicochemical and microbiological characteristics and antioxidant properties of yogurt samples fermented with lactic acid bacteria (LAB) obtained from pickled cabbage. API 50 CHL systems and 16S rRNA nucleotide sequence analyses revealed that the isolates were Lactobacillus casei PC05 and L. acidophilus PC16. Cell counts, titratable acidity, and viscosity of the yogurt samples fermented with L. acidophilus PC16 were significantly higher than those of the samples fermented with L. casei PC05 (P<0.05). The detected cell counts and physicochemical properties were significantly lower in plain yogurt than in soy yogurt (P<0.05). Yogurt samples fermented with L. acidophilus PC16 exhibited higher antioxidant activity, measured as ability to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and chelate ferrous ions, than those fermented with L. casei PC05. However, the ability to scavenge superoxide anions and superoxide dismutase (SOD) activity were significantly (P<0.05) higher in yogurt samples fermented with L. casei PC05 compared to those in samples fermented with L. acidophilus PC16. The antioxidant activity of soy yogurt was significantly (P<0.05) higher than that of plain yogurt. The antioxidant activity of the tested strains resulted in lipid peroxidation inhibition (in vitro), which may be related to the elimination of free radicals, chelating ability, and reducing power. There were no significant differences in the physicochemical properties and antioxidant activities of the yogurt samples during cold storage.

A study on the quality of Naengmyon Broth - Sensory and Microbiological properties by fermentation and addition of Dongchimi- (냉면육수의 품질에 관한 연구 - 동치미 발효 정도와 첨가량에 따른 관능적 및 미생물학적 특성 -)

  • Kim Hyung-Ryurl;Jang Myung-Sook
    • Korean journal of food and cookery science
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    • v.21 no.1 s.85
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    • pp.1-11
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    • 2005
  • The application of Dongchimi liquid into Naengmyon broth for the improved eating quality of Naengmyon was scientifically explored by reviewing the quality properties of the product. Primarily, the optimum fermentation conditions for Dongchimi from which the liquid portion was extracted were pursued and the optimum mixing ratio was sought on the basis of sensory and microbiological properties of the product. The liquid portions which had been periodically extracted from Dongchimi at intervals of two or five days during fermentation at $10^{\circ}C$ were added to Naengmyon broth. The treatments were prepared with three levels, namely, basic broth only('A') and the ratios of 3:7(v/v, 'B') and 5:5(v/v, 'C') of Dongchimi liquid and basic broth, respectively. According to assessments of Dongchimi liquid on taste and intensity based on sensory analyses, the organoleptic factors such as color, smell, sour taste, carbonated taste, and overall acceptability were given higher values from day 11 to day 17 in all items. As for the assessment of Dongchimi liquid on intensity, color, sour odor, moldy odor, and carbonated taste have shown the increasing scores during with high intensities while those for clearness has stayed low. Most of the phenomena observed from the Naengmyon broth substituted with $30\%$ (Treatment 'A') and $50\%$ (Treatment 'B') of Dongchimi liquids with different storage periods ensued much of the previous fermentation pattern of Dongchimi itself. Organoleptic assessment on taste and its intensity showed that better(the best) scores could be obtained at between day 16$\~$25(17) and 13$\~$20(15) for Treatments A and B, respectively. The intensity scores of taste for color, smell, carbonated taste, sour taste, and mouthfeel were increased while those for clearness, palatability, and meaty ones were decreased with lapse of fermentation. The numbers of total cell and lactic acid bacterial counts of Dongchimi has increased until day 13 and then decreased in the later stages. Total cell count and lactic acid bacterial counts of Naengmyon broth also increased until the 13th day and then they began to decrease. It was also proven that slightly over-ripened Dongchimi liquid was more preferable for adding into Naengmyon broth. Granting the optimum ripening period of Dongchimi liquid itself to be 13 days, both Treatment A and Treatment B were evenly favored using Dongchimi liquids slightly over-ripened at days 13 to 17. However, Treatment A was more favored than Treatment B when Dongchimi liquid over-ripened for 20 to 26 days was used.

Physicochemical, Microbiological and Sensory Properties of Vacuum Packaged Yakibuda Products for Export during Cold Storage (수출용 진공포장 야끼부다 제품의 냉장저장 중 물리화학적, 미생물학적 및 관능적 품질 특성)

  • Kim Il-Suk;Jin Sang-Heun;Hah Kyoung-Hee;Lyou Hyun-Ji;Park Ki-Hoon;Chung Ku-Young
    • Food Science of Animal Resources
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    • v.26 no.1
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    • pp.28-36
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    • 2006
  • This study was carried out to investigate the changes in physicochemical, microbiological and sensory properties on vacuum packaged Yakibuda products for Export during storage at $4{\pm}1^{\circ}C$ for 40 days. Yakibuda, Japanese favorite meat product, were produced with three different pork cuts or tenderloin (T1), loin (T2) and ham (T3). The pH of all produce was tend to increased with increase in storage period. After 40 days of storage, pH of T2 was significantly (p<0.05) higher compared to other treatments. TBARS and VBN values of all treatments were increased with increased storage period. The water holding capacity ranged $81.41{\sim}92.20%$ in T1, $81.13{\sim}94.51%$ in T2 and $82.93{\sim}87.50%$ in T3. The shear force of T3 was higher than that of other treatments during whole storage time. The number of microorganism (Total plate counts, Escherichia coli, Lactobacilli spp.) were below 3.0 $log_{10}CFU/cm^2$ during the whole storage period. In sensory evaluation, the score of overall acceptability were above 5.5 point in all products. The storage properties of vacuum packaged Yakibuda could be maintained for 40 days at $4{\pm}1^{\circ}C$ storage temperature.

Sensory and Microbiological Properties of Puchukimchi Prepared with Different Methods (담금방법을 달리한 부추김치의 관능적 및 미생물학적 특성)

  • 박문옥;장명숙
    • Korean journal of food and cookery science
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    • v.16 no.1
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    • pp.65-74
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    • 2000
  • The properties of Puchu(Allium odorum L.)kimchi prepared with different methods were investigated by measuring organoleptic and microbiological properties up to 43 days at 10$\^{C}$ right after preparation. Five conditions of making Puchukimchi included: the addition of salt (treatment A), soybean sauce (treatment B), soybean sauce and perilla seed powder (treatment C), anchovy sauce (treatment D), anchovy sauce and glutinous rice paste(treatment E). Sensory evaluation showed high scores in the appearance, smell, sour taste, good taste, savory taste, texture, and overall acceptability of Puchukimchi prepared with soybean sauce(treatment B). However, treatment C had the best score in good taste. In the intial stage of fermentation, treatment C had higher total microbial counts than others, but in the final stage, treatment E had higher counts than others. Treatment A had less total microbial counts than others throughout the fermentation. The maximum numbers of lactic acid bacteria in other treatments were in the order of treatments A>B>D. In the final stage of fermentation, treatment B had the least number of lactic acid bacteria composed of Pediococcus, Streptococcus, Leuconostoc and Lactobacillus. Streptococcus reached the maximum level at the 8 th day of fermentation, and the number of Lactobacillus was increased with the lapse of fermentation time. It was shown that fermentation patterns of Puchukimchi were influenced by the preparation methods used.

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Microbiological changes and quality characteristics of dried persimmon by chlorine dioxide gas fumigation treatment (이산화염소 가스 훈증 처리에 따른 곶감의 미생물학적 변화 및 품질특성)

  • Moon, Hey-Kyung;Lee, Su-Won;Lee, Wha Jin;Hossein, Abul;Lee, Seul;Kim, Jong-Kuk
    • Food Science and Preservation
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    • v.24 no.5
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    • pp.608-614
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    • 2017
  • This study was conducted to investigate the effect of chlorine dioxide fumigation as a substitute for sulfur fumigation which has been used as a method to prevent the quality change of persimmon during storage and distribution process. Dried persimmons were treated with chlorine dioxide gas concentration (0, 15 30, and 45 ppm) and time (0, 15, 30, and 45 min) and microbiological changes, texture properties and color of the treated samples were investigated during storage at room temperature. Total aerobic bacteria, yeast and mold numbers after chlorine dioxide gas fumigation were decreased when compared with the control group. The inhibitory effects of total aerobic bacteria, yeast, and mold were observed during storage. The texture properties and color value of dried persimmons were not affected by chlorine dioxide gas fumigation concentration and time. There was no difference in quality between chlorine dioxide gas fumigation treatment group and control group. These results suggested that chlorine dioxide gas fumigation treatment can be utilized as a processing technique to secure microbiological storage stability of dried persimmons.

Changes of Physicochemical and Microbiological Properties of Gamma-Irradiated Miscellaneous Cereals (감마선 조사한 잡곡류의 물리화학적, 미생물적 특성 변화)

  • 손인숙;김미라
    • Journal of the East Asian Society of Dietary Life
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    • v.8 no.4
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    • pp.412-421
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    • 1998
  • Physicochemical and microbiological properties of red beans, soybeans, barleys, and corns irradiated by gamma-ray at 1.2 kGy, 10.1 kGy, or 30.5 kGy were investigated. Moisture content and crude lipid content of the irradiated cereals showed no significant difference from the nonirradiated group. TBA values of corns irradiated at 30.5 kGy increased. Gamma irradiation reduced the numbers of mesophilic and psychrotrophic bacteria in the cereals. Yeasts and molds were reduced below detection levels even at 1.2 kGy dose-irradiation. There was no significant difference in reducing sugars between the irradiated cereals and the nonirradiated ones except corns. Stachyose, raffinose, and sucrose of soy beans and sucrose of barleys increased by 30.5 kGy dose-irradiation. Loss of riboflavin content of the irradiated samples was not observed except red beans irradiated at 30.5 kGy. In Hunter's color, b value of the red bean powder increased but L value of the soybean powder decreased by the Irradiation. L, a, and b values of the barley powder slightly increased under 30.5 kGy dose-irradiation and b value of the corn powder decreased under 10.1 or 30.5 kGy-dose irradiation.

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