• Food Science and Preservation
• /
• v.17 no.1
• /
• pp.36-41
• /
• 2010

Fermentation characteristics of yakju prepared with addition of Opuntia ficus indica were examined, with respect to the nature and concentration of additional added materials. The pH level began to decrease after the secondary brewing stage and the total acid content increased during fermentation. The level of reducing sugars in yakju prepared with Opuntia ficus indica increased at the first brewing stage and then slowly decreased after 4 days of fermentation. The ethanol content of supplemented yakju rapidly increased during the initial 6 days of fermentation, to a maximum content of 17.1% after 14 days. The free sugar content was higher in yakju fermented with Opuntia ficus indica stem compared with fruit. The level of organic acids increased as the amount of Opuntia ficus indica material increased. Organic acid level increased during fermentation and lactic acid was the main organic acid in yakju fermented with Opuntia ficus indica. Sixteen volatile compounds were found by GC-MS in supplemented yakju. The most prominent volatile component was iso-amyl alcohol, followed by butyl alcohol and methyl esters. The DPPH radical-scavenging activity of yakju fermented with Opuntia ficus indica stem was higher than when yakju was prepared with fruit. Sensory scores of yakju fermented with 20% (w/v) fruit and 10% (w/v) stem were greater than those of yakju prepared by other treatments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.22 no.2
• /
• pp.196-201
• /
• 1993

In order to investigate some chemical components, higher alcohols, ethyl acetate and volatile compounds of Vitis vinifera red wines were analyzed by HPLC, GC and GC-MS. During the process of ripening for the content of wine and acids were much changed, particurally the content of tartaric acid was decreased largely. Content of total phenolics and phenol flavonoid in wines which manufactured with Malbec varieties as 470mg/L and 245mg/L respectively, was higher than those in Cabernet sauvignon (310mg/L, 135mg/L) and Cabernet franc (425mg/L, 125mg/L) wines, and nonflavonoid was higher in Cabernet franc wine(300mg/L) than in others. Content of acetaldehyde was higher in Malbec wine (33mg/L) than in Cabernet sauvignon (26mg/L) and Cabernet franc (28mg/L) wines. Amount of methyl alcohol, propanol and isoamyl alcohol were higher in Cabernet sauvignon wine than in others, and isobutanol was more in Malbec wine(64mg/L), ethyl acetate was more in Cabernet franc wine as 35mg/L than in Malbec(28mg/L) and in Cabernet sauvignon (23mg/L) wines. Volatile compounds were isolated about 87~91 varieties from concentrates of three red wines by GC, and thirty-five compounds including terpine-4-ol were identified by GC-MS.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.6
• /
• pp.944-950
• /
• 2015

The purpose of this study was to provide a basis for the management of traditional Doenjang by analyzing characteristics of volatile compounds in local Doenjang certified as a traditional food. The main compounds in Doenjang were acids, esters, aldehydes, and pyrazines, whereas relatively high intensities of acetic acid, ethyl alcohol, benzaldehyde, ethyl acetate, ethyl 2-methyl butanoate, 2,5-dimethyl pyrazine, and tetramethylpyrazine were detected among identified compounds. The analysis revealed that the composition of basic volatile compounds in Doenjang was similar, but isovaleric acid, 2-methylbenzaldehyde, tetramethylpyrazine, benzaldehyde, ethyl alcohol, ethyl caprylate, furfural and butanoic acid can serve as marker compounds for quality evaluation since they were specifically abundant in only some kinds of Doenjang. As a result, the quality status of Doenjang certified as a traditional food was determined by constructing a database of the volatile compounds, which can be suggested as a quality control method.

• Korean Journal of Food Science and Technology
• /
• v.30 no.1
• /
• pp.54-61
• /
• 1998

Samjangs (Korean-style mixture of soybean paste) were prepared using magjang, traditional doenjang (Korean style soybean paste), and mixture of traditional doenjang and magjang (a kind of Korean style soybean paste) as a main composition. Charateristics including volatile compounds were investigated. Total sugar in samjang by using magjang was higher than that of other treatment while reducing sugar of the mixed treatment was high. Glutamic acid $(230.6{\sim}310.9\;mg/100\;g)$ was highest among free amino acids. Hunter color values of samjang with magjang was lower than those of others. Volatitle flavor components of smajang were identified with GC and GC-MSD. Fifty four components including 11 alcohols, 7 esters, 13 acids, 3 aldehydes, 4 alkanes, 4 phenols, 3 pyrazine and others were found in samjangs. Ethanol, acetic acid ethyl ester, 3-methyl butanoic acid, 2,4-hexadienoic acid and acetic acid might be major volatile components considering of high peak area. Pentanoic acid methyl ester and 4-methoxy-2-buten-1-ol were higher than other components in samjang with magjang while 2-methyl-1-propanol, butanoic acid and 3-methyl butanoic acid were in samjang with traditional doenjang and ethanol, acetic acid ethyl ester and 2,4-hexadienoic acid were in the mixed treatment.

• Korean Journal of Food Science and Technology
• /
• v.32 no.5
• /
• pp.1035-1042
• /
• 2000

Volatile compounds of kochujang prepared with meju and koji were analyzed by using a purge and trap method during fermentation and identified with GC-MSD. Thirteen alcohols, seventeen esters, seven acids, six aldehydes and nine others were identified. Twenty four volatile flavor detected immediately after making kochujang including 7 alcohols and 9 esters. Six volatile flavor compounds including 1 alcohol and 3 esters were more found after 30 day of fermentation and increased to forty nine of volatile compounds after 150 days. Six alcohols such as ethanol, 3-methyl-butanol, 2-methyl-1-propanol, 1-butanol and nine esters such as ethyl acetate, ethyl butyrate, ethyl caproate, ethyl carpylate and seven others were commonly found through the fermentation period. Peak area (%) of 1-butanol was the highest one among the volatile flavor compounds after 30 day of fermentation and ethanol showed the highest peak area after 60-90 day and 150 day of fermentation, and 3-methyl-1-butanol showed the highest peak area after 120 day of fermentation, 2-Methyl-1-propanol, ethyl butyrate, ethyl acetate, acetaldehyde, ethoxyethene, ethenone, methylbenzene were detected in the kochujang during the fermentation.

• Polymer(Korea)
• /
• v.39 no.1
• /
• pp.78-87
• /
• 2015

With aiming to prepare microcapsules having a particle size of $30-50{\mu}m$, thermally expandable capsules with relatively uniform particle sizes consisting of a n-octane/poly(acrylonitrile-co-methyl methacrylate) core/shell structure were synthesized using SPG membrane emulsification and suspension polymerization. Four steric stabilizers and five crosslinking agents were employed. When poly(vinyl alcohol) as a stabilizer was used, the prepared capsules showed a smooth and regular morphology and the liquid hydrocarbon (n-octane) was well encapsulated in the core. When 1,4-butnaediol methacrylate (BDDMA) was used as a crosslinker, the uniform capsules with the average diameter of $36.8{\mu}m$ were synthesized. The capsules prepared with 0.05 mol% BDDMA showed the best encapsulation efficiency.

• Journal of Mushroom
• /
• v.10 no.1
• /
• pp.44-48
• /
• 2012

In this study, whether Giemsa staining solution can accurately determine bacterial contamination of liquid spawn for Flammulina velutipes in a short period of time was investigated. Giemsa solution staining cells of blood, bone marrow, lymph node, malaria parasites, rickettsia et al. was prepared by dissolving basic methylene azul and methylene blue, and acidic eosine in methyl alcohol-glycerine. Supernatant samples of Flammulina velutipes liquid spawn cultured under explosive aeration were placed on a slide, mixed with Gimesa solution and examined with optical microscope after staining. In 40 to 60 seconds bacterial cells were distinguishable from soybean meal residual and hyphal cell fragments. Thus we conclude that microscopy using Gimesa staining solution is a quick, simple and accurate method for the mushroom growers to effectively use to detect bacterial contamination of the liquid spawn.

• Applied Chemistry for Engineering
• /
• v.5 no.3
• /
• pp.419-424
• /
• 1994

An oil stain on the steel induced by metal working oil was studied on the six kinds of fat and oil compounds(rapeseed oil, oleic acid, methyl oleate, oleyl alcohol, lauryl amino, and lanolin) by MIL-C-22235A test. The samples used for the printing on the oil stain plates were prepared by the addition of fat and oil compounds(10wt% ) and antioxidants(B. H. T, B. T, T. C. P; 0.5wt%) to base oil(spindle oil; 1.5wt% of sulfur). An analysis based on the experimental data indicated that B.T was more effective than B. H. T and T. C. P as antioxidant for inhibiting oil stains. And acid values exerted a bad influence upon the preventation of oil stains. As expected by the chemical structure of fat and oil compound, oleic acid that could react with iron ions produced more stains on the steel pannel.

• Polymer(Korea)
• /
• v.38 no.5
• /
• pp.645-649
• /
• 2014

The causes of residual stress in an injection molded part are high temperature variation and shear stress during molding process. Chemical cracking test is one of the methods of measuring residual stress and cracks are developed according to the degree of residual stress. In this study, the relationship between chemical cracking and exerted stress have been investigated. Deformation jig was designed and used to give a stress through deformation in a specimen. Specimens were molded by a hot press using polycarbonate (PC) and annealed to remove residual stresses in the specimens. Specimens were fixed in the deformation jig and immersed into the solvent to create cracks in the specimens. Solvents were prepared by using tetrahydrofuran and methyl alcohol. As stress accordance with the deformation in the specimen increased, the frequency and density of cracks in the specimen also increased. The results of this study can be used for the measurement of residual stress quantitatively in an injection molded PC product using a chemical cracking method.

• Journal of Ginseng Research
• /
• v.28 no.3
• /
• pp.127-131
• /
• 2004

This study was carried out to investigate the effect of red ginseng water extract (RGWE) on trypsin activity. After extraction of fat soluble and saponin component from red ginseng powder by methyl alcohol, the residue was extracted with distilled water, and manufactured to water extract. The extract was dialyzed with different molecular cut off membrane. Trypsin activity demonstrated the highest level at the RGWE concentration of 9${\times}$10$\^$-2/% in reaction mixture, and also increased to 15% at 2.9${\times}$10$\^$-3/%. Km value was decreased and Vmax was increased in the present of red ginseng water extract. Red ginseng water extract was partially purified by dialysis, Bio-Gel P-I0 and DEAE-cellulose column chromatography. The active fraction demonstrated positive reaction to ninhydrin, DNS and folin reaction.