• Preventive Nutrition and Food Science
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• v.16 no.3
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• pp.253-260
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• 2011

This study was performed to investigate the physical, chemical and microbial characteristics of Gwamegi to provide basic data for the standardization of marine processed foods and for the improvement of the quality of commercial Gwamegi. The acid values of commercial Gwamegi were 5.8, 5.3 and 5.2 mg KOH/g for fillet type (F-type), "two divide" type (T-type) and whole type (W-type), respectively, and the peroxide values were 51.6, 51.5 and 53.2 meq/kg for each. There was a positive correlation between the acid value and the peroxide value (r=0.555) at confidence intervals (CI) of 99%. Trimethylamine (TMA) content of F-type, T-type and W-type products were 2.9, 2.6 and 3.6 mg%, respectively, while volatile basic nitrogen (VBN) contents were 22.4, 21.5 and 21.8 mg%. There was a strong positive correlation between TMA and VBN (r=0.961) at a CI of 99%. The histamine content was detected to be as much as 122 mg/kg, with about 36 % of the samples exceeding the CODEX criteria for histamine of 100 mg/kg. The total microbial count of 4 products exceeded 5 Log CFU/g and coliform group of 11 products exceeded the criteria of less than 1 Log CFU/g. Staphylococcus aureus in 27% of the samples exceeded the criteria of less than 2 Log CFU/g.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.321-328
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• 2004

Nano silica ball and nano carbon ball are developed commercially by template synthesis method. Adsorption of unpleasant smelling substances such as ammonia, trimethylamine, acetaldehyde and methyl mercaptane onto nano carbon ball with hollow macroporous core/mesoporous shell structures, nano carbon ball, was investigated and compared with that onto odor adsorbent materials, activated carbon, commercially available. The adsorption and decomposition of malodor at nano carbon ball exhibited superior than those onto activated carbon. The physicochemical properties such as mesopore size distributions, large nitrogen BET specific surface area and large pore volume and decomposition of malodor were studied to interpret the predominant adsorption performance. The nano carbon ball is expected to be useful in many applications such as deodorizers, adsorbent of pollutants.

• Journal of Environmental Science International
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• v.25 no.5
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• pp.645-654
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• 2016

For the purpose of reuse the wasted by-products from the skate process to the health functional food or medicinal material, chondroitin sulfate was extracted from the skate cartilage with the method of hydrolysis with protease enzyme, and the contents of chondroitin sulfate and hydrolyzed protein were measured qualitatively and quantitatively. The effects of chondroitin sulfate on body weight or liver weight changes, hepatotoxicity elimination and anti-inflammatory actions were measured from in vivo test with feed-treated mice. From the hydrolytic extraction of skate cartilage with the mixture of 1% alcalase and 1% protease for 4 hours, the extraction yield of chondroitin sulfate was about 32.55%. The content and molecular weight of chondroitin sulfate was 26.63% and $2.85{\times}10^5Da$., respectively and the content ratio of chondroitin sulfate to protein was measured to 1 to 2.76 with gel permeation chromatography. For the odor component, trimethylamine decreased about 30% but almost not ammonia from chondroitin sulfate with the treatment of activated carbon. From the feeding chondroitin sulfate to mice, the control effect of body and liver weights decrease was measured, anti-inflammatory action and hepatotoxicity elimination action were also measured. From these results, process operation conditions for manufacturing of chondroitin sulfate were suggested.

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.85-88
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• 1999

Me3NO selectively abstracts the proton from [IrH(CO)(PPh3)2L(A)]0.1+,2+ (1) (A: -CCPh, Cl-, CH3CN and L: CH3CN, Cl-, C1O4-) to give the trans-elimination products, Ir(CO)(PPh3)2(A) (2). The reductive elimination of H+ and Cl- from Ir(H)Cl2(CO)(PPh3)2 (lb) to give IrCl(CO)(PPh3)2 (2b) is first order in both lb and Me3NO. The rate law d[2b]/dt=kobs[lb]=k2[lb][Me3NO] suggests the formation of (PPh3)2(CI)2(CO)Ir-H-ON+Me3 in the rate determining step (k2) followed by the fast dissociation of both H-ON+Me3 and the trans ligand Cl-. The rate significantly varies with the cis liaand A and the trans ligand L and is slower with both A and L being Cl- than other ligands. Me3NO selectively eliminates CO from [Ir(H)2(CO)(PPh3)2L]0,+ (3) (L=CH3CN, C1O4-) to produce [Ir(H)2(PPh3)2L'(CH3CN)]+ (4) (L'=CH3CN, PPh3) in the presence of L. Me3NO does not readily remove either H+ or CO from cis, trans- and trans, trans-lr(H)(-CCPh)2(CO)(PPh3)2 and cis, trans-Ir(H)2Cl(CO)(PPh3)2. The choice whether hydridocarbonyls, 1 and 3 undergo the deprotonation or decarbonylation may be understood mostly in terms of thermodynamic stability of the products and partly by kinetic preference of Me3NO on proton and CO.

• Bulletin of the Korean Chemical Society
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• v.15 no.5
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• pp.379-386
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• 1994

Reactions of 1',2-bis(diphenylphosphino)-l-(N,N-dimethylaminomethyl)ferrocene (FcNPP) with $M(CO)_6$ (M=Cr, Mo, W) in the presence of TMNO (Trimethylamine oxide) in a stoichiometric ratio of 1 : 1.5 : 3.5 produced a series of Gp 6 metal carbonyl derivatives with a variety of coordination modes: M(CO)$_4({\eta}^2$-FcNPP-P,P) (M=Cr, Mo, W), $M(CO)_5({\eta}^1-FcNPP-P) (M=Mo, W)\;,\; M_2(CO)_9({\eta}^1\;,\;{\eta}^2-FcNPP-P,P,N) (M=Cr, Mo)\;,\;M_2(CO)_{10}({\eta}^1\;,\;{\eta}^1-FcNPP-P,P) (M=Cr, Mo, W)\;, and\;W(CO)_4({\eta}^2-FcNPP(O)-P,N)$. All these complexes were characterized by microanalytical and spectroscopic techniques. In one case, the structure of W(CO)$_4({\eta}^2$-FcNPP(O)-P,N) was determined by X-ray crystallography. Crystals are monocinic, space group P$2_{1/C}$, with a=10.147(2), b=19.902(3), c=19.821(4) ${\AA},\;{\beta}=96.88(2)^{\circ},\;V=3974(l){\AA}^3$, Z=4, and $D_{calc}=1.64 g cm^{-3}$. The geometry around the central tungsten metal is a distorted octahedron, with the nitrogen and phosphorus atoms being cis to each other. Some of these complexes exhibited catalytic activities in the allylic oxidation and epoxidation of cholesterly acetate. Other oxidation products were also formed with the different chemical yields and product distribution depending upon the ligand and the central metal.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.241-248
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• 2019

Objective: To isolate and identify new methanogens from the rumen of Holstein steers in Korea. Methods: Representative rumen contents were obtained from three ruminally cannulated Holstein steers ($793{\pm}8kg$). Pre-reduced media were used for the growth and isolation of methanogens. Optimum growth temperature, pH, and sodium chloride (NaCl) concentration as well as substrate utilization and antibiotic tolerance were investigated to determine the physiological characteristics of the isolated strain. Furthermore, the isolate was microscopically studied for its morphology. Polymerase chain reaction of 16S rRNA and mcrA gene-based amplicons was used for identification. Results: One strain designated as KOR-2 was isolated and found to be a non-motile irregular coccus with a diameter of 0.2 to $0.5{\mu}m$. KOR-2 utilized $H_2+CO_2$ and formate but was unable to metabolize acetate, methanol, trimethylamine, 2-propanol, and isobutanol for growth and methane production. The optimum temperature and pH for the growth of KOR-2 were $38^{\circ}C$ and 6.8 to 7.0, respectively, while the optimum NaCl concentration essential for KOR-2 growth was 1.0% (w/v). KOR-2 tolerated ampicillin, penicillin G, kanamycin, spectromycin, and tetracycline. In contrast, the cell growth was inhibited by chloramphenicol. Phylogenetic analysis of 16S rRNA and mcrA genes revealed the relatedness between KOR-2 and Methanoculleus bourgensis. Conclusion: Based on the physiological and phylogenetic characteristics, KOR-2 was thought to be a new strain within the genus Methanoculleus and named Methanoculleus bourgensis KOR-2.

• Journal of Microbiology and Biotechnology
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• v.31 no.12
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• pp.1684-1691
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• 2021

In this study, the physicochemical changes related to fishy smell were determined by storing high hydrostatic pressure (HHP)-treated mackerel (Scomber japonicus) meat in a refrigerator for 20 days. The inhibition of crude urease activity from Vibrio parahaemolyticus using HHP treatment was also investigated. The mackerel meat storage experiment demonstrated that production of trimethylamine (TMA) and volatile basic nitrogen (VBN), the main components of fishy smell, was significantly reduced on the 20th day of storage after the HHP treatment compared to the untreated mackerels. The results demonstrated that the increased ammonia nitrogen rates in the 2000, 3000, and 4000 bar, HHP-treated groups decreased by 23.8%, 23.8%, and 31.0%, respectively, compared to the untreated groups. The enzyme activity of crude urease was significantly reduced in the HHP-treated group compared to that in the untreated group. Measurement of the volatile organic compounds (VOCs) in mackerel meat during storage indicated that the content of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavor due to spoilage, were significantly reduced by HHP treatment. Collectively, our results suggested that HHP treatment would be useful for inhibiting the activity of urease, thereby reducing the fishy smells from fish and shellfish.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.808-815
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• 2022

In this study, gamma-irradiated mackerel (Scomber japonicus) meat was stored in a refrigerator for 20 days to examine the physicochemical changes related to fishy smell. The effect of gamma irradiation on the inhibition of the activity of crude urease extracted from Vibrio parahaemolyticus was also evaluated. Increased levels of trimethylamine (TMA) and volatile basic nitrogen (VBN) content, which are the main components causing fishy smell, were significantly reduced by day 20 of storage after gamma irradiation, indicating that freshness was maintained during storage. The ammonia nitrogen contents of 3, 7, 10, and 20 kGy gamma-irradiated groups were significantly decreased by 6.5, 15.2, 17.4, and 23.9%, respectively, compared to non-irradiated groups on day 20 of storage. In addition, urease activity decreased in a gamma irradiation intensity-dependent manner. Volatile organic compounds (VOCs) were measured during the storage of gamma-irradiated mackerel meat. The contents of ethanol, 2-butanone, 3-methylbutanal, and trans-2-pentenal, which are known to cause off-flavors due to spoilage of fish, were significantly reduced by day 20 of storage. Therefore, gamma irradiation can be considered useful for inhibiting urease activity and reducing fishy smell during fish storage.

• Food Science of Animal Resources
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• v.42 no.4
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• pp.593-608
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• 2022

The effect of hot-air dried Lentinula edodes pileus (DLE) on the quality and organoleptic properties of rolled-dumplings was evaluated. DLE was prepared by drying at 60℃ for 24 h and added (Non, 7%, and 9%) to rolled-dumplings. The proximate composition, pH, color (CIE L^*, a^*, b^*), and cooking yield were analyzed. Texture profile analysis, electronic-nose (e-nose), electronic-tongue (e-tongue), and organoleptic evaluation were also conducted. The cooking yield of dumplings with 9% DLE was significantly lower than that of the congeners without DLE, whereas 7% DLE did not lead to significant differences compared without DLE. With increasing DLE addition, the pH and lightness of the dumplings decreased significantly, whereas the redness tended to increase. The texture profile was significantly higher for the dumplings with DLE compared to those without DLE. E-nose analysis confirmed that DLE addition led to the positive odors (methanethiol: meaty, sulfurous; 3-methylbutanal: malty, toasted) and the negative odors (trimethylamine: ammoniacal; acetic acid: acidic, sour). E-tongue analysis showed that DLE addition decreased the intensity of the sourness and increased the intensity of the saltiness and umami of rolled-dumplings. DLE addition improved the overall organoleptic properties, but 9% DLE can be recognized as a foreign substance in organoleptic acceptance. Consequently, DLE has the potential to serve as a flavor and odor enhancer for rolled-dumplings, and the addition of DLE can positively improve consumer acceptance by improving the quality and organoleptic properties.

• Animal Bioscience
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• v.35 no.12
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• pp.1977-1985
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• 2022

Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure. Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons. Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p<0.001). In the CPRS group, the odor intensity outside was significantly lower in the fall than in the other seasons (p = 0.015). In the indoor atmosphere, the temperature and CO₂, NH₃, and H₂S contents of the CPRS group were significantly lower than those of the control group (p<0.05). In the CPRS group, indoor temperature did not significantly change in the spring, summer, and fall seasons and was significantly lower in the winter (p = 0.002). NH₃, H₂S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p<0.05). There were significant seasonal differences on the odorous material in both the control and CPRS groups (p<0.05), but the pattern was not clear across seasons. Conclusion: The CPRS can reduce the indoor temperature in the summer to a level similar to that in the spring and fall seasons. The CPRS with aerated liquid manure is expected to reduce and maintain malodorous emissions within acceptable limits in swine facilities.