• Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.393-405
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• 2023

The aim of this research was to enhance the flavor of visceral extracts from skipjack tuna. Flavor precursors and the optimum condition for the Maillard reaction were determined. The flavor extract was prepared from the tuna viscera using Endo/Exo Protease controlled in 3 factors; temperature, enzyme amounts and incubation time. The optimal condition for producing tuna viscera protein hydrolysate (TVPH) was 60℃, 0.5% enzyme (w/w) and 4-hour incubation time. TVPH were further processed to tuna viscera flavor enhancer (TVFE) with Maillard reaction. The Maillard reactions of TVFE were conducted with or without supplements such as xylose, yeast extract and methionine. The Maillard volatile components were analyzed with gas chromatography-mass spectrometry. Sixteen volatiles such as 2-methylpropanal, methylpyrazine, 2,5-dimethylpyrazine, dimethyl disulfide and 2-acetylthaizone were newly formed via Maillard reaction and the similarity of volatile contents from TVPH and TVFE were virtualized using Pearson's correlation integrated with heat-map and principal component analysis. To virtualize aromagram of TVPH and TVFE, odor activity value and odor impact spectrum (OIS) techniques were applied. According to OIS results, 3-methylbutanal, 2-methylbutanal, 1-octen-3-ol 2,5-dimethylpyrazine, methional and dimethyl trisulfide were the potent odorants contributed to the meaty, creamy, and toasted aroma in TVFE.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.1
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• pp.21-29
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• 1994

Subzonal insemination(SUZI) has been proposed for patients with severe male factor and previous fertilization failure. However, very low fertilization rates still persisted. The aims of this study were firstly, to examine the relationships between the fertilization rate and sperm parmeters, sperm incubation media and time, secondly, to evaluate the outcome of 119 cycles of SUZI applied the modified sperm preparation method. The fertilization rates were influenced more sensitively by sperm preincubation media and time than by sperm parameters. According to preincubation media and time, the fertilization rates were 43.3% in 50% follicular fluid (HFF), 36.6% in 10% fetal cord serum(FCS), and with the time, increased in FCS, but decreased in HFF. In regrd with sperm parameters, the fertilization rates were 42.9% in normal and 37.6% in subnormal group. The best results were obtained from SUZI by the spermatozoa incubated in 50% HFF for 6-8 hours. So we tried 119 cycles of SUZI(normal; 39 cycles, subnormal; 80 cycles) using the preparation method of 6-8 hour incubation in 50% HFF. There were no signigicant differences in the fertilization rates between normal(125/269, 46.4%) and subnormal sperm(264/635, 41.6%). Contrary to the fertilization rates, pregnancy outcomes were different between both groups. Better results obtained from the subnormal group than the normal in the number of transferred embryos, that of good embryos, and developmental rate of the fertilized eggs. The pregnancy rates per transfer were totally 13.3%(13/98),20.0%(13/65) in subnormal group. In the normal group, 2 patients showed ${\beta}$-hCG positive, but resulted in chemical pregnancy. Of 13 clinical pregnancies, two aborted, 6 on-going, and 5 delivered. In conclusion, SUZI is an effective technique to overcome fertilization failure for male factor and unexplained. The fertilization rate is influenced by sperm parameters, sperm incubation media and time. Also the quality of oocytes might be important for pregnancy as same as that of sperm.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.5
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• pp.546-560
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• 2013

In this study, a natural fermentation starter formulation was developed for manufacturing Korean bread products by substituting baker's yeast with naturally fermented blueberry starters. As the incubation time of the blueberry extracts increased, the pH and total titratable acidity increased. The sweetness (brix%) of blueberry extracts containing various amounts of sugar were higher than the other sample. The result of alcoholicity for naturally fermented blueberry extracts, the fermented blueberry extract containing 20% sugar was highest. Lactic acid bacteria counts increased until the 4th day; however, it decreased from the 5th day, and viable yeast counts increased consistently until the 5th day. The volume for naturally fermented blueberry extracts increased as the incubation time increased. As the fermentation time of blueberry starters increased, the pH of bread dough decreased. The RVA analysis conveyed that wheat flour retrogradation was retarded by increasing the blueberry starter content. The weight of pan breads containing blueberry starters were higher than that of the control, while the volume, specific volume and baking loss rate were lower than those of the control. The moisture content of pan breads containing blueberry starter decreased as storage time increased. In analyzing the visible mold colony during 7 days of storage at $28^{\circ}C$, mold growth in pan breads containing the blueberry starter was retarded. The hardness of breads containing blueberry starters were significantly increased as storage time increased. The breads containing 50% naturally fermented blueberry starter have acceptable sensory properties. In conclusion, these results indicated that 50% of natural fermentation blueberry starter could be very useful as a substitute for yeast when making naturally fermented bread.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.453-458
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• 2002

In order to search for reliable rapid methods of estimating bacterial counts in pork, this study was tried to measure resazurin reduction time which is simple in experimental method, low in analytical cost, able to estimate bacterial count within short time. The results were summarized as follows; Correlation coefficient between initial bacterial log count(25$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 25$^{\circ}C$ and 30$^{\circ}C$ was higher than other conditions as -0.95 and -0.94, respectively. Considering correlation coefficient and reduction time, incubation temperature was compatible at 30$^{\circ}C$, and regression equation(RE) was Y = -0.4386X + 7.7870. At a bacterial load of $10^2$cfu/$cm^2$, $10^3$cfu/$cm^2$ and $10^4$cfu/$cm^2$ in pork, reduction time was 13.2hr, 10.9hr and 8.6hr, respectively. Correlation coefficient between initial bacterial log count(30$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 30$^{\circ}C$ was highest among other conditions as -0.93, and RE was Y = -0.4171X + 7.5540. At a bacterial load of $10^2$cfu/$cm^2$, $10^3cfu/$cm^2$ and $10^4cfu/$cm^2$ in pork, reduction time was 13.3hr, 10.9hr and 8.5hr, respectively. Correlation coefficient between initial bacterial log count(35$^{\circ}C$/72hr, Y) and resazurin reduction time(X) from blue color to pink color during incubation at 30$^{\circ}C$ was highest among other conditions as -0.93, and RE was Y = -0.3514X + 6.7513. At a bacterial load of $10^2$cfu/$cm^2$, $10^3$cfu/$cm^2$ and $10^4$cfu/$cm^2$ in pork, reduction time was 13.5hr, 10.7hr and 7.8hr, respectively.

• Journal of Animal Science and Technology
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• v.49 no.2
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• pp.213-224
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• 2007

In this study, hatched male broiler chicks(Ross) were fed on a basal diet and LPS was administered via intraperitoneal injection three times every other day, on the 9th, 11th and 13th days of the experiment, and then PBMC and splenocytes were isolated on day 14. The degree of alama blue reduction was evaluated at 4, 24, 48, 96 and 120 h in the splenocytes, and at 4, 8, 12, 24 and 48 h for PBMC of incubation after the addition of alama blue solution to the media. The cell numbers used in this experiment were 103, 104 and 105 cells per well, and the con A levels were 0.0, 1.0, 5.0, and 10.0 ㎍ per ml of medium. 1. The degree of alama blue reduction was found to increase in a linear fashion with increasing incubation time and cell numbers, for both splenocytes and PBMC. 2. During acute phase response, the degree to which alama blue was reduced was significantly elevated (p<0.05) at an incubation time of 24 hr for the splenocytes, 4 hr for PBMC, and a cell number of 105 cells per well, respectively. 3. The raised reduction of alama blue to control was linear with Con A levels in medium, and higher reduction in Con A 10.0 ㎍ relative to 1.0 or 5.0 ㎍ in ml medium was shown 4. The medium with autologous serum evidenced a significantly (p<0.05) higher reduction of alama blue relative to FBS. 5. Splenocytes and PBMC from the LPS-injected birds evidenced significantly higher levels of alama blue reduction regardless of incubation time, number of cells, level of Con A added, or serum type, as compared with what was observed in normal birds. The results indicated that the assay conditions for proliferative activity using the alama blue method in birds in which the acute phase response had been activated via intraperitoneal LPS injection requires 4 hrs of incubation for PBMC, 24 hrs of incubation for splenocytes, and 10㎍ of Con A per ml of medium.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.1
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• pp.49-60
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• 2008

A study was conducted to determine the effect of alcohol-fermented feedstuff formulated with byproducts on the fermentation characteristics and dry matter disappearance in the rumen. Dietary treatments were either a soybean curd-based alcohol-fermented feedstuff(AFS) and brewery grain-based alcohol-fermented feedstuff(AFB). The AFS and AFB are composed of 50% commercial beef cattle feed, 50% soybean curd dreg, 5% molasses and 0.5% yeast, and 25% commercial beef cattle feed, 25% brewery grain, 25% soybean curd dreg, 25% corn grit, 5% molasses and 0.5% yeast, respectively. The ruminally cannualted Korean cattle were utilized to investigate the change of ammonia, pH alcohol, volatile fatty acids, and DM digestibility at 0, 2, 4, 8 and 12 hr after feeding. The rumen ammonia concentrations were significantly lower in AFS and AFB with incubation time, especially at 6 hr incubation(AFS, 0.7 mg/dl; AFB, 1.5 mg/dl; control 2.5 mg/dl). Lower rumen pH was observed in AFS and AFB during the early stage of incubation, but no significant difference was found at late stage of incubation. The total VFA concentrations were not affected by diet treatments at 2 hr incubation time, but the concentration significantly decreased after that. The dry matter disappearance was significantly lower in AFS and AFB during the early stage of incubation. However, the dry matter disappearance of AFS and AFB was similar to that of control during the late stage of incubation. It is concluded that the industrial byproducts such as soybean curd dreg and brewery grain were effective materials to make an alcohol fermented feedstuffs and resulted in better fermentation characteristics in the rumen when both were applied to Hanwoo.

• KSBB Journal
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• v.29 no.5
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• pp.316-322
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• 2014

Xylanase have been used to convert the polymetric xylan into fermentable sugars from the production of ethanol and xylitol from plant biomass. The aim of this study was to isolate and identify xylanolytic bacterium from herbivore feces and was to used the xylanase for enzymatic hydrolysis of biomass. Xylanolytic strains were isolated from 59 different feces of herbivores from Seoul Grand Park located in Gwacheon Gyeonggi-do. The xylanolytic strains were selected by congo red staining and DNS method. Total 67 strains isolated from the herbivores feces were tested for xylanase activity. Among the strains, H10-1, which has the highest xylanase activity, was isolated from feces of Ceratotherium simum. The H10-1 strain was identified as Bacillus pumilus based on its morphological/biochemical characteristics and partial 16S rDNA gene sequences. Culture conditions of B. pumilus H10-1 such as initial medium pH, incubation temperature and incubation time were optimized for maximum xylanase production. And also xylanase produced by B. pumilus H10-1 was applied for the saccharification of Miscanthus sacchariflorus cv. 'Geodae 1', which was pretreated with 1.5M NaOH. The optimized culture conditions of B. pumilus H10-1 were pH 9, $30^{\circ}C$ incubation temperature, and 7 day incubation time, respectively. This xylanase activity under the optimized conditions was $20.4{\pm}3.3IU$. The crude xylanase produced by B. pumilus H10-1 was used for the saccharification of xylan derived from pretreated 'Geodae 1'. The saccharification conditions were $50^{\circ}C$, 200 rpm, and 5 days. Saccharification efficiency of pretreated 'Geodae 1' by B. pumilus H10-1 was 8.2%.

• Parasites, Hosts and Diseases
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• v.50 no.3
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• pp.239-242
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• 2012

The influence of temperature on the development and embryonation of Ascaris suum eggs was studied using coarse sand medium in an environmental chamber with 50% humidity. The time required for development and embryonation of eggs was examined under 3 different temperature conditions, $5^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$. A. suum eggs did not develop over 1 month at the temperature of $5^{\circ}C$. However, other temperature conditions, $25^{\circ}C$ and $35^{\circ}C$, induced egg development to the 8-cell-stage at days 5-6 after incubation. All eggs examined developed to the 8-cell stage at day 6 after incubation in the sand medium at $25^{\circ}C$. The higher temperature, $35^{\circ}C$, slightly accelerated the A. suum egg development compared to $25^{\circ}C$, and the development to the 8-cell stage occurred within day 5 after incubation. The formation of larvae in A. suum eggs at temperatures of $35^{\circ}C$ and $25^{\circ}C$ appeared at days 17 and 19 after incubation, respectively. These findings show that $35^{\circ}C$ condition shortens the time for the development of A. suum eggs to the 8-cell-stage in comparison to $25^{\circ}C$, and suggest the possibility of accelerated transmission of this parasite, resulting from global warming and ecosystem changes.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.717-722
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• 2004

Response surface methodology was used to optimize production conditions of monoacylglycerol (MAG) and diacylglycerols (DAG) from corn oil by enzymic glycerolysis. Contents of $1,3-DAG\;(Y_1),\;1,2-DAG\;(Y_2),\;total\;DAG\;(Y_3),\;MAG\;(Y_4)$, and total $DAG+MAG\;(Y_5)$ were obtained. Conditions were optimized using central composite design with incubation temperature $(35-75^{\circ}C,\;X_1)$, incubation time (1-11 hr, $X_2$), and amount of hexane added (0-2 mL, $X_3$) as three variables. Content of 1,3-DAG was maximized by 20.43 area% at incubation temperature of $44.92^{\circ}C$, incubation time of 10.24 hr, and hexane content of 1.16 mL, whereas that of 1,2-DAG (26.78 area%) was maximized at $56.32^{\circ}C$, 6.95 hr, and 1.04 mL, respectively. Predicted maximum total DAG content was 45.09 area% at $53.82^{\circ}C$, 8.03 hr, and 1.08 mL, while production conditions of MAG (9.57 arae%) were $64.14^{\circ}C$, 7.00 hr, and 0.13 mL. At variables of $54.07^{\circ}C$, 7.98 hr, and 1.02 mL, maximum content of total DAG+MAG predicted by RSM was 53.54 area%.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.775-787
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• 2018

This study was conducted to investigate for the natural methane emission inhibitor as a feed additive no adversely effect on rumen fermentation. Five different Control (Wheat barn (0.05 g), MRA(Methane Reduction Additive)-1 (Allium fistulosum L. (0.05 g)), MRA-2 (Sodium Lauryl Sulfate (0.025 g) + Wheat barn (0.025 g) mixed), MRA-3 (Sodium Dodecyl Sulfate (0.025 g) + Wheat barn (0.025 g) mixed), and MRA-4 (Allium fistulosum L. (0.02 g) + Tannic acid (0.02 g) + Wheat barn (0.01 g) mixed) contents were used to perform 3, 6, 9, 12, 24 and 48 h incubation for in vitro fermentation. Ruminal pH values were ranged within normal ruminal microbial fermentation. Dry matter digestibility was not significantly different across the treatments during the whole fermentation time. Also, the result of microbial growth had no adversely effect on during the whole fermentation time. At 24 h, methane emission was significantly lower (P<0.05) than all treatments except to MRA-1. Especially, MRA-4 carbon dioxide emission was significantly lower (P<0.05) than control at 9, 24 and 48 h incubation. In addition MRA-4 propionate concentration was significantly higher (P<0.05) than control at 24 h incubation. The result of RT-PCR Ciliate-associated methanogens were significantly lower (P<0.05) at MRA-1, MRA-3 and MRA-4 than control at 24 h incubation. Based on the present results, MRA-4 could be suggestible methane emission inhibitor as a natural feed additive.