• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.23 no.2
• /
• pp.77-86
• /
• 1990

The residue after hot water extraction of blue crab, Portunus trituberculata, was hydrolyzed for utilizing the byproducts as seasonings. The acid(5N HCl) hydrolyzates were then neutralized with $Na_2CO_3$, 5N NaOH or 5N NaOH hydrolyzate, while the alkali hydrolyzates (5N NaOH) were also neutralized with 5N HCl or 5N HCl hydrolyzate. The total nitrogen and formol nitrogen contents increased, and the platability of the hydrolyzates was also enhanced by neutralization. The released amino acid contents from the neutralized hydrolyzates with $Na_2CO_3$, 5N NaOH and 5N NaOH hydrolyzate were $2,274mg\%,\;2,105.0mg\%$ and $2,683.5mg\%$, respectively. Amino acid contents from the neutralized hydrolyzates with 5N HCl and 5N HCl hydrolyzate were $1,352.5mg\%$ and $2,498.8mg\%$, respectively. In the decolorization of hydrolyzates using decolorization agent, powdered active carbon showed good decolorizing effect. Powdered active carbon decreased total nitrogen and formol nitrogen contents in direct relationship to the increase in its concentration. The effective concentration of active carbon used as decolorization agent showed as $1\~2\%$ of the crab hydrolyzate. Salt contents could be decreased at 37 brix by desalination method such as the evaporation of the hydrolyzate contents.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.3
• /
• pp.192-197
• /
• 2000

To develop plain dried products of large anchovy, Engraulis japonica, lipid oxidation during drying of large anchovy and optimal drying condition were investigated. The moisture contents of large anchovy on 7 hrs dryness were $ 9.0{\%},\;34.0{\%},\;38.0{\%} and\;38.8{\%}\;in\;60^{\circ}C$ hot-air drying (wind velocity, 1.4m/sec), $40^{\circ}C$ hot-air drying (wind velocity, 1.4 m/sec), sun drying($30{\pm}5^{\circ}C$) and $20^{\circ}C$ cold-air drying (wind velocity, 3.1 m/sec), respectively. The cold-air drying depressed remarkably the lipid oxidation of large anchovy during drying, resulting from AV, POV, COV and the formation of browning pigment. The fatty acid composition of large anchovy was $35.8{\%} in saturates, 20.0{\%} in monoenes and 44.2{\%}$ in polyenes. Saturates and monoenes were increased in proportion to the increase of drying time, while polyenes were decreased. The contents of 20 : 5 and 22 : 6 of polyenes were decreased remarkably in proportion to the progress of lipid oxidation, while 14 : 0, 16 : 0, 16 : 1 and 18 : 1 of saturates and monoenes were increased. The changes in fatty acid compositions by drying conditions were remarkably clarified in sun drying, followed by $60^{\circ}C$ hot-air drying $40^{\circ}C$ hot-air drying and $20^{\circ}C$ cold-air drying in order.

• Korean Journal of Food Science and Technology
• /
• v.26 no.3
• /
• pp.266-271
• /
• 1994

The curd yogurt (total solid content: 14%) was prepared from milk added with skim milk powder and potato puree. Potato puree comprised 9.5. 13,8 and 17.9% (dry basis) of the milk-potato mixture, and the effect of potato on the quality of yogurt was investigated. Addition of potato remarkably stimulated acid production and propagation of lactic acid bacteria, and viable cells reached above $3.9{\times}10^{10}$ CFU/ml after 12 hours. As potato content increased, the ratio of lactic acid content to total acidity decreased, while citric acid increased. The major organic acids of yogurt were lactic acid, citric acid, and acetic acid. Viscosity of yogurt was increased in proportion to the increment of the potato content. After 24 hours of incubation, the sensory score of yogurt containing 13.8% (dry basis) potato showed better sensory acceptability. When curd yogurt added with potato was kept at $5^{\circ}C$ for 15 day, its keeping quality was relatively good. Viable cells of lactic acid bacteria and ${\beta}-galactosidase$ activity decreased rapidly at pH 1.5, and 2.5, but the group added with potato was more stable than control.

• Food Science and Preservation
• /
• v.23 no.6
• /
• pp.765-771
• /
• 2016

Omija-cheong, concentrated extracts from sugar-treated Omija fruit (Schisandra chinensis Baillon), is produced by traditional manner in Korea. The quality characteristics of Omija-cheong processed at low temperature with a pilot-scale were investigated to optimize the incubation time. With increasing incubation time in processing Omija-cheong, the pH level of Omija-cheong remained constant, while titratable acidity and organic acids increased. Fresh Omija fruits contained citric, malic and succinic acids, most of which were extracted into concentrated extracts after 37 days of incubation and reached to the stable concentration after 47 days of incubation. Titratable acidity in Omija-cheong gradually increased from 1.18% to 2.71%, and also was correlated with total concentration of organic acids. About 80% of supplemented sucrose for manufacturing Omija-cheong was converted into glucose and fructose until 68 days of incubation, and the composition of free sugars was maintained to be stable up to 138 days of incubation. The contents of total flavonoids and phenolic compounds in Omija-cheong were 24.1 mg-GAE/L and 1,635 mg-QE/L at 57 days of incubation, which were more than 9 and 5 times higher than those in Omija fruits, respectively. From the quality characteristics in processing Omija-cheong by low-temperature incubation, more than 60 days of incubation is required for the constant quality and value-added beverage.

• Korean Journal of Food Science and Technology
• /
• v.29 no.5
• /
• pp.1006-1015
• /
• 1997

Whole soybean meju was fermented with four Bacillus strains for 45 hr in its model system. The pH range of the product was $7.98{\sim}8.68$, the contents of amino nitrogen and ammoniacal nitrogen were $286{\sim}439\;mg%,\;0.11{\sim}0.23%$, respectively and that of reducing sugar ranged $0.65{\sim}2.24%$. During fermentation, the enzyme activities increased up to $30{\sim}40\;hr$ of fermentation and slightly decreased after 45 hr. Stachyose was special sugar components for B. licheniformis and raffinose was for B. natto. The components of the organic acid showed distinctive patterns among four products and the patterns of amino acids and fatty acids were almost similar to those of other reports. The main and common odor concentrates of meju were pyrazine components, 3-methyl-1-butanol, acetic acid and ethanol. Chunggukjang, mixed with B. natto and B. licheniformis showed more acceptabilities than other combinations. Soybean paste, mixed with B. megaterium and B. subtilis, soysauce, mixed with B. megaterium and A. oryzae showed excellent acceptability, respectively.

• Food Science and Preservation
• /
• v.13 no.1
• /
• pp.18-23
• /
• 2006

This study was carried out to analyze the quality change of mackerel treated extracts of Diospyros kaki, Teuceriun veronicoides and Zanthoxylum schinifoliun during storage to develope the preparation methods for high quality of salted mackerel. The mackerel treated with Z schinifoliun extract was lowest pH change among group. Titration acidity of mackerel was increased during storage at $4^{\circ}C\;and\;25^{\circ}C$. The changes of acid value (AV) of mackerel were lower treated herbal extracts at early storage than those in control group (5.79 meq/kg) at $4^{\circ}C$. Acid values were increased in all group at $25^{\circ}C$ during storage. Peroxide value (POV) was 10 meq/kg in the salted Mackerel. Increasing of peroxide values was lower in the salted mackerel during storage. Contents of volatile basic nitrogen (VBN) were increased during storage, and were lower in group treated herb extracts than in control group. Total viable cells of mackerel were more in groups treated hem extracts at early storage than in control group, but less in groups treated herb extracts during storage than in control group.

• Journal of Animal Environmental Science
• /
• v.18 no.3
• /
• pp.229-234
• /
• 2012

Disinfecting contaminated swine manure with FMD (Foot-and-Mouth Disease) and pathogenic viruses is very important for maintaining sanitized environment. However, very few research reported on this subject, especially post-disinfection to utilize the wastes as a renewable resource. This research is carried out to obtain basic information for chemical treatment in FMD SOP (Standard Operating Procedure, Korea) of contaminated swine manure. Using lime, sodium hydroxide, citric acid and hydrochloric acid, described in FMD SOP, the effects of chemical treatments on livestock manure were compared in this paper. Four combinations of alkali-acid treatments and four kinds of acid-alkali combinations were tested to find out the effective method. Total coliform bacteria in contaminated swine manure, $1.6{\times}10^4$ CFU/100 ml, decreased to the range of 1/1000~1/100 in all treatments. Some specific disinfectants increases BOD (Biochemical Oxygen Demand) and EC(Electric Conductivity), especially, alkaline treatments increases ammonia level than acid treatments. These findings suggest that the treatment methods should be considered as an important environmental factor in post-disinfection of contaminated animal manure with pathogenic microorganisms.

• Korean Journal of Environment and Ecology
• /
• v.25 no.1
• /
• pp.102-110
• /
• 2011

The study aims to provide future implications for planning nature trails called Dullegil in the national park located in the city in Korea as new visiting culture for sustainability of environment and use. The telephone survey used quota sampling with 300 Seoulite ages from 20 to 69 by area, gender, and age, which was conducted to find out the perception on a Dullegil in Bukhansan National Park. The result shows more than 65% of Seoulite go climbing and aiming the mountain top as a general visitor behavior. The intention to use Dullegil was very high at 58%, which forecasts the use of Dullegil as a substitute for a trail to the intensified mountain top. However, the effectiveness of Dullegil to divert intensive use could be limited as the major group of climbers showed relatively low intention to use Dullegil as an alternative. As for the management direction, majority favors balanced management between use and conservation, even if conservation was preferred to use. Most important guiding principle for building Dullegil was conservation of environment, the planning direction should be oriented to conserve the ecological environment of Bukhansan, and to enjoy its value. Facilities for visitor safety was most needed. Most preferable time and length were 1~3 hours and 11~20km, each. This study has a limitation as the site was limited to Bukhansan and potential demand for use was analyzed with the sample of Seoulite only. To come up with the results generally applicable, more detailed future researches by the visitor segmentation, use behavior, and demand are needed.

• Microbiology and Biotechnology Letters
• /
• v.32 no.3
• /
• pp.249-255
• /
• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Food Science and Preservation
• /
• v.18 no.1
• /
• pp.26-32
• /
• 2011

We added Nuruk at various proportions to brown rice Takju, and investigated the quality characteristics of vinegar produced in agitated culture and static culture. The more Nuruk was added, the higher the alcohol concentration. However, when over 30% (w/w) Nuruk was present, the increment in alcohol content was low (maximum 13.5%, v/v). A comparison of the quality of brown rice vinegar produced in agitated culture with that of vinegar produced in static culture showed that titratable acidity in agitated culture vinegar was highest after fermentation with 30% (w/v) Nuruk, at 5.97%. In static culture, the greater the amount of Nuruk added after 16 days of fermentation, the higher the titratable acidity of vinegar produced; this was true upon addition of either 30% (w/v) or 40% (w/v) Nuruk. Free amino acid levels increased in both agitated and static cultures as the level of added Nuruk rose. Moreover, brown rice vinegar produced in static culture had a higher level (7-30%) of total free amino acids than did vinegar produced in agitated culture. In particular, the level of gamma-amino butyric acid, a functional fortifier, was 3-5-fold higher in vinegar produced in agitated culture. The results thus indicate that both the amount of added Nuruk and the type of fermentation affected the level of free amino acid production. A static culture is expected to undergo changes in aroma and sensory characteristics during fermentation, indicating that further research on vinegars is required.