• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1773-1778
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• 2009

Guava (Psidium guajava L.) contains high amount of vitamins and minerals, and its leaves have been reported to be very effective on reducing blood pressure. In this study, antimicrobial characteristics of extracts from four different parts of guava (fruit, branch, leaf, and seed) with four different solvents (methanol, ethanol, acetone, and water) were evaluated. Four targeted food-borne microorganisms were selected; two Gram negatives (Escherichia coli O157:H7 and Salmonella Typhimurium) and two Gram positives (Staphylococcus aureus and Listeria monocytogenes). By the paper disc method, guava extracts showed stronger clear hollow zone against Gram positive bacteria than Gram negatives in nutrient broth agar plate. Especially, extracts of branches and leaves showed significant antibacterial activity. Guava extracts also showed significant inhibition activity on the growth of Gram positive food-borne bacteria in nutrient broth. For example, S. aureus did not grow at all at 200 ppm of acetone extracts of guava branch and leaf. In the case of L. monocytogenes, the same concentration of acetone extracts of guava branch and leaf inhibited the growth 33.5% and 55.4%, respectively, at 32 hrs of incubation time. The results indicated that extracts of guava branch and leaf showed significant antibacterial activities against food-borne Gram positive microorganisms, and that guava branches, the byproducts of guava, might be a valuable resource for antibacterial materials.

• Journal of Life Science
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• v.14 no.5
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• pp.788-793
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• 2004

Fermented milk was prepared from skim milk supplemented with Salicornia herbacea extract powder (SHEP) at the levels of 0∼0.4% (wi v) and was fermented with Lactobacillus acidophilus, Streptococcus thermophillus and Bifidobacterium longum. Quality characteristics of prepared fermented milk were evaluated for acid production, visible cell numbers, viscosity and sensory property during fermentation at 37$^{\circ}C$ for 6 hr. Supplementation of 0.1% SHEP stimulated the growth of lactic acid bacteria which showed the highest number of viable cell counts (9.23 log CFU/ml), and also enhanced the acid production which was pH 4.23 and titratable acidity 0.64%, and increased the viscosity (1,365 cps) after 6 hr incubation. The sensory scores of fermented milk supplemented with 0.1% SHEP were higher than other supplemented contents in taste, texture, flavor, aftertaste and overall acceptability. When the storage abilities of fermented milk supplemented SHEP at 6$^{\circ}C$ for 12 days were evaluated, its quality-keeping properties were relatively good in the fermented milk supplemented with 0.1% SHEP.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.214-214
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• 2017

Seeds of Tomato (Lycopersicon esculentum Mill.) have demanded high quality because of their high cost of seed. The optimization of the seed priming techniques that have positive effect on fast and uniform germination becomes important at the commercial level. Several factors such as solution composition, osmotic potential, and treatment duration affect seed priming response. In this study, osmotic potentials of priming solution and germination characteristics of primed seed were investigated to clarify the effects different inorganic salt types and the duration. Tomato seeds were primed in osmotic solutions that were osmotic potential ranged -1.54 to -0.45 MPa in an aerated solution of PEG 8000 (17%, 22%, 27%), and inorganic salt solution of $KNO_3$, $Na_2SO_4$, and $K_2SO_4$ (100, 200, 300mM). The seeds were treated at $20^{\circ}C$ for 2, 4, and 6 days. After each treatment, the seeds were dried to moisture content ranged 5-8% at $25^{\circ}C$. Four replications of 25 seeds per each treatments were placed in 10-cm petri dishes containing two filter papers and 3 ml of $dH_2O$ and incubated at $20^{\circ}C/30^{\circ}C$ and $15^{\circ}C$ and seedlings evaluated for abnormality after 14 days of incubation. Seed water potential (${\psi}$) was correlated with water potential of priming solution ($r^2=0.86$). Seeds primed in 100mM $KNO_3$ resulted the highest germination rate (GR, $63.9 %{\cdot}day^{-1}$) and lowest mean germination time (MGT, 2.0 days) comparing to untreated control ($23.9%{\cdot}day^{-1}$ of germination rate and 4.1 days of MGT) at $20/30^{\circ}C$, even though 96% of germination percentage were not different. Seeds primed in 100mM $KNO_3$ (${\psi}=-0.45MPa$) for 4 days showed ${\psi}=-0.38MPa$. Priming in $Na_2SO_4$, $K_2SO_4$, and PEG solution for 6 days improved MGT and GR, but not significantly than 4 days of treatment. Additionally, stepwise osmotic solution treatment with 100mM and 300mM concentration for 6 day did not showed differences with single treatment. In relation to osmotic potentials, identical osmotic potential in different inorganic salt solution showed different effect on germination characteristics.

• Journal of the Korean Wood Science and Technology
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• v.38 no.3
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• pp.251-261
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• 2010

Cellulase from Formiptosis pinicola KMJ812 is an efficient cellulose degradation enzyme complex, especially with a high ${\beta}$-glucosidase activity. In this study, the change in enzymatic characteristics by immobilization and the reduction of immobilized enzyme activity by repeated usages were evaluated using cellulases from F. pinicola KMJ812. Among tested four resins, Duolite A568 resin had the best enzyme activity yield with 61.7% cellulase activity and 64.4% ${\beta}$- glucosidase activity during the cellulase immobilization. The best reaction temperature was $55^{\circ}C$ for both cellulase and ${\beta}$-glucosidase activities which were higher than the unimmobilized soluble cellulases. The best reaction pH was 4.0 for cellulase activity which was a little more basic than a soluble form and 4.5 for ${\beta}$-glucosidase activity. The immobilized cellulase activity was remained 98% of the beginning activity after 72 h incubation at $50^{\circ}C$ and 50% of the beginning activity after eight times usage at $50^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.358-365
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• 2013

A series of in vitro studies were carried out to determine i) the effects of enzyme and formaldehyde treatment on the degradation characteristics of carbohydrate and protein sources and on the synchronicity of these processes, and ii) the effects of synchronizing carbohydrate and protein supply on rumen fermentation and microbial protein synthesis (MPS) in in vitro experiments. Untreated corn (C) and enzyme-treated corn (EC) were combined with soy bean meal with (ES) and without (S) enzyme treatment or formaldehyde treatment (FS). Six experimental feeds (CS, CES, CFS, ECS, ECES and ECFS) with different synchrony indices were prepared. Highly synchronous diets had the greatest dry matter (DM) digestibility when untreated corn was used. However, the degree of synchronicity did not influence DM digestibility when EC was mixed with various soybean meals. At time points of 12 h and 24 h of incubation, EC-containing diets showed lower ammonia-N concentrations than those of C-containing diets, irrespective of the degree of synchronicity, indicating that more efficient utilization of ammonia-N for MPS was achieved by ruminal microorganisms when EC was offered as a carbohydrate source. Within C-containing treatments, the purine base concentration increased as the diets were more synchronized. This effect was not observed when EC was offered. There were significant effects on VFA concentration of both C and S treatments and their interactions. Similar to purine concentrations, total VFA production and individual VFA concentration in the groups containing EC as an energy source was higher than those of other groups (CS, CES and CFS). The results of the present study suggested that the availability of energy or the protein source are the most limiting factors for rumen fermentation and MPS, rather than the degree of synchronicity.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.3
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• pp.355-362
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• 2017

Objective: The use of locally produced forage (LPF) in cattle production has economic and environmental advantages over imported forage. The objective of this study was to characterize the nutritional value of LPF commonly used in Korea. Differences in ruminal fermentation characteristics were also examined for the LPF species commonly produced from two major production regions: Chungcheong and Jeolla. Methods: Ten LPF (five from each of the two regions) and six of the most widely used imported forages originating from North America were obtained at least three times throughout a year. Each forage species was pooled and analyzed for nutrient content using detailed chemical analysis. Ruminal fermentation characteristics were also determined by in vitro anaerobic incubations using strained rumen fluid for 0, 3, 6, 12, 24, and 48 h. At each incubation time, total gas, pH, ammonia, volatile fatty acid (VFA) concentrations, and neutral detergent fiber digestibility were measured. By fitting an exponential model, gas production kinetics were obtained. Results: Significant differences were found in the non-fiber carbohydrate (NFC) content among the forage species and the regions (p<0.01). No nutrient, other than NFC, showed significant differences among the regions. Crude protein, NFC, and acid detergent lignin significantly differed by forage species. The amount of acid detergent insoluble protein tended to differ among the forages. The forages produced in Chungcheong had a higher amount of NFC than that in Jeolla (p<0.05). There were differences in ruminal fermentation of LPF between the two regions and interactions between regions and forage species were also significant (p<0.05). The pH following a 48-h ruminal fermentation was lower in the forages from Chungcheong than from Jeolla (p<0.01), and total VFA concentration was higher in Chungcheong than in Jeolla (p = 0.05). This implies that fermentation was more active with the forages from Chungcheong than from Jeolla. Analysis of gas production profiles showed the rate of fermentation differed among forage species (p<0.05). Conclusion: The results of the present study showed that the nutritional values of some LPF (i.e., corn silage and Italian ryegrass) are comparable to those of imported forages widely used in Korea. This study also indicated that the nutritional value of LPF differs by origin, as well as by forage species. Detailed analyses of nutrient composition and digestion kinetics of LPF should be routinely employed to evaluate the correct nutritional value of LPF and to increase their use in the field.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.355-365
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• 2004

Two experiments were conducted to determine the effect of alkaline hydrogen peroxide (AHP) treatment (1% NaOH+1.5% $H_2O_2$; 1 AHPMS, 2% NaOH+1.5% $H_2O_2$; 2AHPMS) on rate and extent of degradation of mustard straw (MS) in sacco in sheep, and its in vivo digestion and ruminal fermentation characteristics when fed to sheep with concentrate (200 g per sheep daily). The treatment of straw with 1 and 2% AHP increased its sodium content by 148 and 296% to that of untreated straw (UMS). There was significant decrease in NDF and hemicellulose contents of AHP treated straw and increase in cellulose and lignin contents. Phenolic acids like ferrulic, $\rho$-coumaric and o-coumaric significantly (p<0.001) reduced by AHP treatment of mustard straw. In first experiment the in sacco degradation of DM, OM and NDF was significantly (p<0.01) greater for 2 AHPMS than for UMS at all incubation periods. The disappearance of nutrient from 1 AHPMS and 2 AHPMS treated straws continue to increase up to 96 h whereas in UMS the peak disappearance was found at 48 h. By using the equation {(y=a+b) ($1-e^{-ct}$)} the degradation rates (c) for DM, OM, and NDF were significantly higher for UMS than AHP treated straws. Level of alkali (1 and 2%) had significant effect on degradation characteristics (a, b, c and $P_{0.05}$) of DM and NDF fraction of MS. However, the effect was not pronounced on OM fraction of MS. In feeding experiment, the intake of nutrients for DM, OM, cell wall constituents and energy was higher on 2 AHPMS, whereas no effect on the digestibility of these nutrients was observed. The apparent nitrogen retention was higher (p<0.05) both in 1 and 2 AHPMS groups. Water intake by animals was significantly increased due to AHP treated mustard straw feeding. Rumen liquor pH was higher in 2 AHPMS fed animals. The $NH_3-N$ of rumen liquor was not affected by feeding of AHP treated MS based diets. Total VFA concentration was significantly (p<0.01) higher in UMS fed group. The fractional out flow rate of DM was higher (p<0.05) in animals fed on 2 AHPMS diets compared to UMS and lAHPMS fed groups. The population of large holotrichs was higher (p<0.05) on AHP treated MS fed diets compared to UMS. The study indicated that treatment of mustard straw with AHP changed its chemical composition towards a better feed. The nutritive value of 2% AHP treated mustard straw was better in terms of dry matter intake and apparent nitrogen retention. The higher in sacco DM, OM and NDF disappearance however, was not confirmed by in vivo data in this study.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.154-159
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• 2006

It is essential to understand the decomposition characteristics for developing the optimum anaerobic digestion system of organic wastes. In this study, BMP (Biochemical Methane Potential) test using serum bottle was conducted to evaluate the anaerobic degradability of fish offal. 3 different groups of fish offal including waste from mackerel and hairtail handling except viscera and fish viscera were chosen for the substrates. Grinded fish offal was transferred anaerobically to serum bottle in amounts of 50 ml, 100 ml and 150 ml, respectively. BMP test was carried out in triplicate. Cumulative methane production and methane production rate depending on incubation time were evaluated. These results varied depending on substrate characteristics. The average values of ultimate methane yield ranged between $420ml{\cdot}CH_4/g{\cdot}VS$ and $490ml{\cdot}CH_4/g{\cdot}VS$, and the methane production and degradation rate of viscera were higher than those of other parts of fish offal. According to the analysis of elemental composition, average C/N ratio of fish offal used in this study was 5.2. Theoretical ultimate methane yield calculated from elemental composition was $522ml{\cdot}CH_4/g{\cdot}VS$. Biodegradability was calculated as 0.847.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.484-489
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• 1997

The characteristics of growth and esterase activity of bacterial strains isolated from acid hydrolysed soybean protein were examined. All the isolated strains having decomposition activity of p-hydroxybenzoic acid butyl ester and esterase producing activity were identified as Bacillus sp. by morphological and biochemical methods. The specific growth rates, esterase activities and p-hydroxybenzoic acid butyl ester decomposition activities of isolated strains were $0.844{\sim}1.213\;h^{-1}$, $21{\sim}222\;mU/ml$ and $5.4{\sim}8.1\;mU/ml$, respectively. In the fermentation of Bacillus sp. KB8 strain which had the highest esterase producing activity, growth, extracellular excretion and intracellular synthesis of esterase were inhibited by adding NaCl in the culture broth. Esterase producing activity gradually increased after late exponential growth phase, until maximum value of 420 mU/ml reached after 64 hours culture period. Esterase of Bacillus sp. KB8 strain was stable up to $50^{\circ}C$ for 30 minutes, but was inactivated by heating for 30 minutes at $70^{\circ}C$. The enzyme activity exponentially decreased during the incubation time at the temperatures of $60^{\circ}C$ and $65^{\circ}C$.

• Journal of Life Science
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• v.24 no.1
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• pp.46-53
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• 2014

Lactobacillus sakei 383, which showed the highest GABA content in fermented soycurd, survived in artificial gastric fluid (pH 3.0) up to 3 h, and the survival rate was 88%. L. sakei 383 was tolerant to bile juice during incubation in MRS broth with 0.3% oxgall, and the survival rate was 99%. The survival ratio of L. sakei 383 was high in media containing less than 6% NaCl. L. sakei 383 produced an antibacterial substance against various pathogens, including Listeria monocytogenes, Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella typhi. The quality characteristics of soycurd fermented with L. sakei 383 were measured during the fermentation period. The viable cell number reached a peak ($10^{11}CFU/ml$) 36 h after fermentation and then slowly decreased. According to the fermentation time of L. sakei 383, the acidity of soycurd increased and the pH decreased until 12 h, and they were maintained thereafter. The moisture, crude ash, crude protein, crude fat, and crude fiber content was 94.88, 0.22, 2.38, 1.16, and 0.03%, respectively. The content of total and reducing sugar was comparatively higher in the soycurd fermented with L. sakei 383 than in nonfermented soycurd. The essential and nonessential amino acid content was 11.2 and 38.65 mg/100 g.