• KSBB Journal
• /
• v.24 no.6
• /
• pp.508-514
• /
• 2009

This study investigated the production of catalase from Bul-kyo soil bacteria through fermentation process. Isolation and selection of bacteria was performed through chemical and physiological analysis. Catalases were produced from bacteria which belong to 3 different species (Bacillaceae bacterium BKBChE-1, Bacillus sp. BKBChE-2, Bacillus flexus BKBChE-3) confirmed by using 16S rDNA sequence method. The catalases were found to be stable in the temperature range of $30^{\circ}C-60^{\circ}C$ for BKBChE-1, BKBChE-2 and BKBChE-3 and also in the pH range of 9.0-12.0 for BKBChE-1 and BKBChE-3. Long-term stability of the catalases was about 20 days at $4^{\circ}C$. However, BKBChE-2 has kept its activity over 30 days at $4^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.43 no.2
• /
• pp.235-239
• /
• 2011

Liquid-state fermentation of Monascus koji was performed using 10% honey as the nutrient source. The rheological characteristics of flour doughs with added red koji broth were evaluated and revealed the following results. The falling number which represents the paste characteristics decreased, as the amount of added red koji broth increased. Adding 10% broth resulted in a falling number of $363{\pm}7.8s$ and with 20% it was $318{\pm}2.1s$. In the measurement of gelatinization using a rapid visco analyzer, increasing the red koji broth decreased peak viscosity, peak viscosity time, holding strength, final viscosity and set-back values, but initial pasting temperature and breakdown value increased. In the farinograph measurements, no significantly different absorption was found between the control and the treatments, and the results were 64.3-65.0%. The consistency and tolerance index of the doughs were higher in the treatments than the control. Increasing the broth addition ratio increased the measurement values, however development time and time to break down the doughs decreased. Stability also decreased and adding 20% broth resulted in a 9.3 min development time, and adding 40% broth resulted in a 3.0 min development time. In the alveographic analysis, the $P_{max}$ (overpressure) value of the control was 158.0 mm. $P_{max}$ value increased to 190.0 mm after adding 40% broth. However the values of L, G and W were higher in the control. As a result, little influence on dough rheology was observed by adding red koji broth 20%.

• The Korean Journal of Mycology
• /
• v.9 no.3
• /
• pp.117-122
• /
• 1981

A tunnel system of mushroom cultivation was designed to compare with the conventional cultivation method in Korea. The bed and air temperature during the phase II the tunnel system was more stably controlled than in the conventional house. The indipensable energy was much saved in the tunnel system than in the conventional method, as this system did not require additional heat supply in the phase II. Compost fermented in the tunnel was proved to contain higher total nitrogen and moisture than compost in the conventional house. Residual ammonia content of compost fermented in the tunnel did not exceed 300ppm. Mushlroom mycelial growth in the tunnel was as good as in conventional house. The tunnel system did not require additional heat supply during mycelial growth period. Mushroom yield and quality from the tunnel system was 5 per cent higher and better than that of the conventional method.

• Food Science and Preservation
• /
• v.15 no.6
• /
• pp.852-858
• /
• 2008

This study investigated the rheological properties of bread dough supplemented with lotus (Nelumbo nucifera) seed powder. The rheological properties measured were dough volume, farinogram, amylogram, extensogram, pH and outernal. The lotus seed powder contained 7.74% moisture, 20.15% crude protein, 2.11% crude fat, 4.34% crude ash, and 2.78% crude fiber. The farinogram showed that with increasing concentration of lotus seed powder the absorption rate of the dough increased slightly, the development time and stability decreased, and the degree of attenuation tended to be grown along. From the amylogram it was found that the gelatinization onset temperature and the maximum viscosity of the dough tended to increase with increasing content of lotus seed powder. The extensogram showed that the degree of extension of the dough decreased with increasing content of lotus seed powder, while the degree of resistance and resistance/extensibility increased. The dough pH tended to decrease with fermentation time, but increased with increasing content of lotus seed powder. A concentration of $5{\sim}10%$ lotus seed powder appears to be suitable for the preparation of dough.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.5
• /
• pp.684-688
• /
• 2003

The objective of this study was to search for the best strain as a source of L- $\alpha$-glycerophosphate oxidase (GPO) production and to establish the process technology for the purification of GPO on an industrial scale. The GPO was produced by culturing Streptococcus faecium, and purified by ammonium sulfate, DEAE-cellulose and hydroxyapatite chromatography. The relative activity was 60 units/L for 5. faecim ATCC 12755, 65 units/L for 5. faecium ATCC 19634, and 67 units/L for 5. faecium $M_{74}$.LC, respectively. The optimum condition for fermentation was $37^{\circ}C$ for temperature, 300 rpm for stir rate, 0.5 L/min for aeration rate and 17 hours. The main culture medium prepared by the modified AC medium. AC medium consists of 0.1% glucose, 0.2% glycerol, 1.0% tryptone and 1.0% yeast extract, 0.5% $K_2HP0_4$, pH 7.0. The GPO was purified by ammonium sulfate fractionation and ion exchange column chromatography, The yield and purity were 17.2% and 5.3 fold, respectively.

• Journal of Nutrition and Health
• /
• v.7 no.3
• /
• pp.45-50
• /
• 1974

Geep-Jang, a kind of soybean paste, was made from vegetables such as egg-plant, green cucumber and green red pepper besides grains, which was fermented at $55{\sim}60^{\circ}C$ incubator or room temperature for a week. In order to determine the effect of cellulolytic enzymes addition on the Geep-Jang processing, samples were taken by 0, 24, 48, 72, 96, 120, and 144 hours interval after first stage, chemical composition were measured and its results obtained as follows: 1. Reducing sugar was rapidly increased from twenty to forty hours after first stage. 2. Large contents of reducing sugar at G-5 group might originated from the much quantity of carbohydrate sources and speed up the decomposition of raw materials by cellulolytic enzymes. 3. The different content of reducing sugars between G-1 and G-3 group should stemed from the addition of enzymes solution and it's differences were very remarkable id the case of classic soybean koji power 4. The contents of amino-nitrogen was generally more increased than the classic one(G-2, G-4). 5. Fermentation period of Geep-Jang may reduce by addition of cellulolytic enzymes.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.25 no.1
• /
• pp.15-21
• /
• 2017

In the present work, the synergistic effect of seaweed addition on organic acid production from sludge was investigated. The batch experiment was conducted at various mixing ratios of sewage sludge and seaweed (100:0, 75:25, 50:50, 25:75, 0:100 on a COD basis) under the substrate concentration of 20 g COD/L. The fermentation temperature was conducted under mesophilic condition ($35^{\circ}C$) and a heat-treated ($90^{\circ}C$ for 20 min) anaerobic digester sludge was used as a seeding source to suppress the methanogenic activity, The results showed that the amount of organic acid production increased as the content of seaweed increased: organic acids were 1.45, 3.22, 4.28, 5.24 and 4.82 g COD/L for the mixing ratio of 100:0, 75:25, 50:50, 25:75 and 0:100 respectively. The synergistic effect was calculated based on the organic acid production of individual sludge and seaweed, and was found to be 0.92, 1.14, 1.26 g COD/L at the mixing ratio of 75:25, 50:50 and 25:75, which indicates that 40% of synergy was obtained when 25% of seaweed was added. The synergistic effect could be ascribed to the high C/N ratio and biodegradability of seaweed.

• Applied Biological Chemistry
• /
• v.44 no.3
• /
• pp.185-190
• /
• 2001

Alginate, a well-known biopolymer, is universally applied for immobilization of microbial cells. Biosorption characteristics of lead by waste biomass of immobilized A. niger beads, used in fermentation industries to produce citric acid, were studied. The immobilized A. niger beads, prepared via capillary extrusion method using calcium chloride, were applied in the removal of lead. Pb uptake was the highest in A. niger beads cells grown for 3 days with medium producing citric acid (12% sucrose, 0.5% $NH_4NO_3$, 0.1% $KH_2PO_4$, and 0.025% $MgSO_4$). Lead uptake by the immobilized A. niger beads and free A. niger mycellia beads increased sharply with time. However, while uptake by the immobilized A. niger beads continued to increase slowly, that by free A. niger mycellia beads stopped after 30 min. The optimum pH and temperature of lead uptake were found to be 6 and $35^{\circ}C$, respectively. The maximum uptake of lead was achieved with $50{\sim}100$ beads and 50 ml lead solution in a 250-ml Erlenmeyer flask, while, at over 100 beads, uptake of the lead decreased. The order of biosorption capacity for heavy metals was Pb>Cu>Cd. Pb uptake capacity of the immobilized A. niger beads treated with 0.1 M $CaCI_2$, 0.1 M NaOH, and 0.1 M KOH decreased compared to the untreated beads. On testing the desorption of Pb from the immobilized A. niger beads, re-uptake of Pb was found possible after desorption of the binding metal with 0.1 M HCI.

• Korean Journal of Food Science and Technology
• /
• v.43 no.5
• /
• pp.648-654
• /
• 2011

Staphylococcus aureus, a major human pathogen, produces a wide array of toxins, which causes various types of disease symptoms. Prevalence of S. aureus in various foods collected during 2006-2008 in Korea was investigated. S. aureus was isolated from 275 of 5,186 (5.3%) food samples collected from hyper-markets in Korea. Seasonal temperature affected the prevalence of S. aureus in various foods with high isolation rate during the summer. Most of the enterotoxigenic strains produced enterotoxin A only or enterotoxin A in combination with another toxin. A total of 54.5% of the tested strains contained either one or more enterotoxin genes and 3.6% possessed a tst gene. This study offers basic information for securing the stability of food during storage and circulation, and provides an epidemiological tool to study the cause, origin and temporal spread of S. aureus food poisoning.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.26 no.1
• /
• pp.13-20
• /
• 1993

Traditional fermented fish products 'Jeodtgal' have been prepared with addition of about $25\%$ salt to prevent spoilage, but domestic seasoned and fermented products have only about $8\%$ salt, so they have been required careful treatment during distribution and could have a different fermentation pattern from traditional 'Jeodtgal' This study was conducted to establish shelf-life of seasoned and fermented squid at different distribution conditions. To establish shelf-life of seasoned and fermented squid stored at $10^{\circ}C,\;20^{\circ}C$ and $30^{\circ}C$, chemical components and sensory evaluation were investigated. Chemical components such as volatile basic nitrogen(VBN), ammonia nitrogen ($NH_3-N$) and total nitrogen(T. N) rapidly increased during storage at $20^{\circ}C$ and $30^{\circ}C$, but pH value and Hunter color value(${\Delta}E$) slowly decreased during storage without respect of storage temperature. Judging from chemical components analysis and senseory evaluation, seasoned and fermented squid could be storage for 3days at $30^{\circ}C$, 7days at $20^{\circ}C$ and 25days at $10^{\circ}C$, respectively. The ratio of quality deterioration per hour were 0.00166 at $10^{\circ}C$, 0.00595 at $20^{\circ}C$ and 0.01385 at $30^{\circ}C$.