• Journal of the Korean Society of Food Culture
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• v.23 no.6
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• pp.667-680
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• 2008

The moisture contained in conventionally extracted red crab shell samples was lower than than in samples extracted using high pressure. In contrast, ash content increased as the extraction time increased and displayed no significant variation in high pressure extraction. Extraction time was influential, with lower lightness (L-value) being obtained in samples extracted at high pressure as compared to traditional extraction. However, large variation in a- and b-values resulted from traditional extraction. For both traditional and high pressure extraction increases in pH, salinity and saccharide content were noted with increasing extraction time, but these parameters did not vary substantially in red crab shell extracted at high pressure. The mineral content in samples extracted by high pressure was higher than in traditionally extracted samples. The mineral content increased with time, with marginally higher contents of essential amino acids and flavor enhancing amino acids noted following high pressure extraction. The contents of the flavor enhancing amino acids increased from 30?60 min, thereafter decreasing. Assessment of consumer acceptance revealed that, while traditionally manufactured red crab sauce was popular, sauce manufactured using a 60 min high pressure extraction was preferred. Extending the high pressure extraction time to 75 min produced a less sensory acceptable product, due to higher mineral and protein levels.

• Journal of the Korean Society of Food Culture
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• v.36 no.3
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• pp.325-332
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• 2021

This study sought to investigate the effects of heat-moisture treatment (HMT) and ethanol treatment (EOH) for improving the quality and storage stability of Tteokbokki Tteok. The quality characteristics were evaluated by moisture, pH, color, texture profile analysis, and observing the microbial properties after the heat-moisture treatment or ethanol treatment. As the storage period increased, the moisture content of Tteokbokki Tteok tended to decrease except for the HMT group (p<0.05) while the pH did not show significant variation except for the EOH group (p<0.05). While measuring the color, the L-value tended to increase in all groups during the storage period. The a-value and the b-value showed the highest values in the HMT group and the control (CON) group, respectively. In the texture profile analysis, all groups showed a significant tendency to increase levels of hardness and chewiness as the storage period increased (p<0.05). The HMT group showed an increase in hardness and adhesiveness, which are characteristics of the HMT treatment. The results of examining the microbial properties of Tteokbokki Tteok showed that the total microbial count in the HMT group was 4.52 on the 8^th day of storage, which was lower than the level in the CON group and the EOH group on the 4^th day of storage. Yeast and mold were not measured during the storage period. Thus the results of this study showed that when manufacturing Tteokbokki Tteok, the heat-moisture treatment of rice powder increased the storage stability by delaying microbial growth and also had positive effects on quality.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.151-156
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• 1991

Bovine in vitro fertilization experiment was carried out using ovary-derived follicular oocytes and frozen-thawed spermatozoa to determine the optimal preincubation time of spermatozoa and the insemination time for successful in vitro fertilization rate. The possibility of parthenogenetic cell division of unfertilized oocytes during culture without spermatozoa was also examined. There was no significant (p>0.05) difference in percent ratio of embryos developed to blastocyst stage between 0 and 3 h preincubation times of spermatozoa, showing a tendency to have higher percentage for 0 h of preincubation time. The 6 h insemination time seemed to be better for producing higher percentage of ova cleavage compared with those of 1 and 3 h treatments. Approximately 10% of unfertilized oocytes divided into 2 to 4-cell stage, and some of them cleaved to 5 up to 8-cells. The results obtained from this study suggested that 0 h of sperm preincubation time and 6 h of insemination time would be suitable for producing better in vitro fertilization rate of bovine oocytes. It is also likely that unfertilized bovine oocytes probably cleave to some cell stages with irregular divisions of the cells. On the one hand, considerable variation was also found in spermatozoa function among individual bulls.

• Journal of Animal Science and Technology
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• v.62 no.2
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• pp.227-238
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• 2020

Use of raw feedstuffs for livestock is limited by low digestibility. Recently, fermentation of feedstuffs has been highlighted as a new way to improve nutrient absorption through the production of organic acids using inoculated microorganisms, which can also play a probiotic role. However, standard procedures for feedstuff fermentation have not been clearly defined because the process is influenced by climatic variation, and an analytical standard for fermented feedstuffs is lacking. This study aimed to evaluate the microbiological and biochemical changes of feedstuffs during fermentation at temperatures corresponding to different seasons (10℃, 20℃, 30℃, and 40℃). We also investigated the effects of yeast, lactic acid bacteria (LAB), and Bacillus spp. on fermentation and determined the results of their interactions during fermentation. The viable cells were observed within 8 days in single-strain fermentation. However, when feedstuffs were inoculated with a culture of mixed strains, LAB were predominant at low temperatures (10℃ and 20℃), while Bacillus spp. was predominant at high temperatures (30℃ and 40℃). A significant drop in pH from 6.5 to 4.3 was observed when LAB was the dominant strain in the culture, which correlated with the concentrations of lactic acid. Slight ethanol production was detected above 20℃ regardless of the incubation temperature, suggesting active metabolism of yeast, despite this organism making up a marginal portion of the microbes in the mixed culture. These results suggested that fermentation temperature significantly affects microbiological profiles and biochemical parameters, such as pH and the lactic acid concentration, of fermented feedstuffs. Our data provide valuable information for the determination of industrial standards for fermented feedstuffs.

• Journal of Aquaculture
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• v.10 no.4
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• pp.457-462
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• 1997

During the period of the Cochlodinium polykrikoides red tide occurrence in the southern coast of Korea in 1997, we obseved the vertical migration of red tide organisms in situ, along with environmental factors such as water temperature, dissolved oxygen, pH, chlorophyll $\alpha$ and nutrients for practical application of loess suspension techniques ot diminish fisheries damage. To cope with serious outbreaks of red tide of C. polykrikoides, the finfish culturists resorted with loess suspension to disperse the bloom watermass by turning around it with fishing boats in full speed. Peak in afternoon the cell numbers were diminished in the surface layer after sunset red tide organisms settled down in the middle and bottom layer progressively again after sunrise. Chlorophyll $\alpha$ and dissolved oxygen showed the same trends of variation with the cell number. In the course of controlling the red tide with loess suspension we could not find any severs oxygen deficiency to kill the culture species.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.137-141
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• 2002

An experimental study was undertaken to quantify the effects of insect hormones on the replication of nucleopolyhedrovirus (NPV). The results demonstrated that TCID/ sub 50/ at 72 h post-infection (hpi) rose systematically from 0.55$\times$10$^{8}$ /m1, for untreated cells, up to 1.67$\times$10$^{8}$ / ml at 3$\mu$g/ml, then dropped down to 1.45$\times$10$^{8}$ /m1 at 4 $\mu$g/ml, by adding ecdysone to the culture medium for Bm-N cells infected with a wild-type Bambyx mori. nucleopolyhedrovirus (BmNPV). The optimum enhancement of about 3 times on budded virus (BV) titer at 72 hpi was given at 3 $\mu$g/ml of ecdysone. While the polyhedra number had no obvious variation within the range of concentrations from 0 to 4 $\mu$g/ml. By addition of juvenile hormone analogue (JHA) into the media with this concentration range, the BmNPV TCID/ sub 50/ and polyhedra number at 72 hpi did not show significant changes. Also, the addition of either 3 $\mu$g/ml of ecdysone or 3 $\mu$g/ml of JHA to the culture media did not appear to affect the TCID/ sub 50/ and polyhedra number significantly in infected Sf-21 cells with the autographa californica nucleopolyhedrovirus (AcMNPV).

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.84-91
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• 2021

The oriental plum (Prunus salicina) is one of the most popular fruits in Korea due to its sweet taste and pleasant aroma. The objective of this study was to analyze the quality characteristics and antioxidant activities of a puree made using plums stored at low-temperatures. The quality characteristics were determined by estimating total soluble solids (TSS, °Brix), titratable acidity (TA, % citric acid), TSS/TA ratio, pH, colors, sugar content, and sensory profiles. The antioxidant effects were estimated by total polyphenol and flavonoid content and radical scavenging activity. The results showed that the plum puree containing both the flesh and the peel had markedly higher red coloration (a⁎ value) than the puree without the peel, while yellow coloration (b⁎ value) and lightness (L⁎ value) were lower in the puree without the peel than with the peel. The sensory qualities including the plum taste and flavor, texture as well as overall acceptance showed no significant variation between the samples. Meanwhile, the total polyphenol/flavonoid content and radical scavenging activities were significantly improved by the presence of fruit peel and by frozen storage. These findings suggest that frozen plums could be a suitable ingredient for making a puree and concentrate for the food manufacturing industry.

• Journal of Life Science
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• v.19 no.7
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• pp.994-1002
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• 2009

A bacteriocin-producing bacterium identified as Bacillus licheniformis was isolated from soybean sauce. Antibacterial activity was confirmed by paper disc diffusion method, using Micrococcus luteus as a test organism. The bacteriocin also showed antibacterial activities against Bacillus sphaericus, Lactobacillus bulgaricus, Lactobacillus planiarum, Paenibacillus polymyxa, and Pediococcus dextrinicus. Optimal culture conditions for the production of bacteriocin was attained by growing the cells in an MRS medium at a pH of 6.5~ 7.0 and a temperature of 37$^\circ$C for 36$\sim$48 hr. Solvents such as chloroform, ethanol, acetone, and acetonitrile had little effect on bacteriocin activity. However, about 50% of bacteriocin activity diminished with treatment of methanol and isopropanol at the final concentration of 50% at 25$^\circ$C for 1 hr. It was stable against a pH variation range from 3.0 and 7.0, but the activity reduced to 50% at a pH range from 9.0 to 11.0. It's activity was not affected by heat treatment at 100$^\circ$C for 30 min and 50% of activity was retained after heat treatment at 100$^\circ$C for 60 min, showing high thermostability. The bacteriocin was purified to a homogeneity through ammonium sulfate precipitation, SP-Sepharose ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (HPLC). The entire purification protocol led to a 75-fold increase in specific activity and a 13.5% yield of bacteriocin activity. The molecular weight of purified bacteriocin was estimated to be about 2.5 kDa by tricine-SDS-PAGE.

• Journal of Naturopathy
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• v.7 no.1
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• pp.10-19
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• 2018

The purpose of this study was to investigate the distribution and variation of the anion and cation number in the aerosols at 16 sites in the Jeju area. The average value of anion counts was raged from 449.35 ions/cm³ at Jeju city to 3471.25 ions/cm³ in the Chunjiyeon falls. In order, the lowest Jeju-si < hamdeok < 1100 m < farm < gyorae A < saryoni < jeolmul < gyorae B < geomunoreum < halla forest < hallasan garden < seongpanak < dongbaeksan < jeongbang < wonyang, respectively. There was statistically significant difference between the anion counts of the measured values in the order of elevation. The mean value of cation measurements was from 90 ions/cm³ for Cheonjiyeon, to 729.8 ions/cm³ for Halla forest garden, which showed the highest value. In order, the lowest 729.8 ions/cm³ of Cheonjiyeon < 1100 m < dongbaeksan < Jeju-si < saryoni < wonyang < seongpanak < hamdeok < jeongbang < gyorae B < jeolmul < Farm < gyorae A < halla forest < geomun and < halla garden, respectively. The geographically low area and the high area were measured low and difference in the two ions. The differences between the content of the anion, cation and/or altitude were significant each other in the variance analysis. The correlation between the anion and cation content and/or altitude was statistically significant (r=.396, p<.001). In conclusion, the result of showing the temporal distribution and variation of the anion and cation content in the aerosols in Jeju island forests provides important information for healthcare.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.470-481
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• 2023

Algal overgrowth in shrimp culture ponds can affect the quality of the aquatic environment, thereby adversely affecting the shrimp and causing economic losses. The objective of this study was to evaluate the variation in phytoplankton composition in intensive shrimp ponds in Bac Lieu province, Vietnam. Phytoplankton samples were collected in three black tiger shrimp (Penaeus monodon) ponds and three whiteleg shrimp (Litopenaeus vannamei) ponds. The collected data were analyzed using SPSS and canonical correlation analysis softwares. In total, 75 species of phytoplankton were recorded in black tiger shrimp ponds and 64 species in whiteleg shrimp ponds. Diatoms had the highest species diversity with 29-30 species (39%-47%), followed by green algae with 9-19 species (14%-25%); species numbers of other phyla varied from 5-12 (8%-16%). The total number of phytoplankton species throughout the study varied from 34-50 species. Algal density was relatively high and ranged from 497,091-2,229,500 ind./L and 1,301,134-2,237,758 ind./L in black tiger shrimp and whiteleg shrimp ponds, respectively. The diatom density tended to increase during the final stage of the production cycle in black tiger shrimp ponds. Blue-green algae and dinoflagellates also increased in abundance at the end of the cycle, which can affect shrimp growth. Diatoms were significantly positively correlated with pH, salinity, total ammonia nitrogen, and nitrate (NO₃^-) concentrations (p < 0.05). Blue-green algae and dinoflagellates were positively correlated with salinity, phosphate (PO₄^3-), and NO₃^-. Algal species diversity was lower in the whiteleg shrimp ponds than in the black tiger shrimp ponds. Several dominant algal genera were recorded in the shrimp ponds, including Nannochloropsis, Gyrosigma, Chaetoceros, Alexandrium, and Microcystis. The results of this study provide basic data for further investigations, and they contribute to the management of algae in brackish-water shrimp ponds.