• Title/Summary/Keyword: incubation time and temperature

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Studies on Quality Changes and Antioxidant Activity During the Fermentation of the Salt Fermented Whangseoke (황석어(Collichthys nireatus Jordan et starks) 젓갈의 숙성과정 중 품질변화와 항산화작용에 관한 연구)

  • Kim, Ji-Sang;Moon, Gap-Soon;Lee, Kyung-Hee;Lee, Young-Soon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.2
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    • pp.171-176
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    • 2006
  • The effect of storage temperature on the quality and antioxidative activity Whangseoke sauce was studied over a period of 240 days. Fermented Whangseoke with $25\%$ salt were stored at $25^{\circ}C$. The quality change and antioxidant activity of Whangseoke in linoleic acid emulsion was evaluated with various parameters including acids values, peroxide values, TBA values, reducing sugar, brown color intensity, electron donating ability and reducing power at various time intervals for 240 days of storage. In general, it was observed, in all sample, that peroxide values, brown color intensity, electron donating ability and reducing power gradually increased, while reducing sugar decreased during storage at $25^{\circ}C$. The antioxidative activities of fermented Whangseoke were determined on tile linoleic acid emulsion system. The results showed that Whangseoke had antioxidant activity. These results suggest that antioxidant activity of Whangseoke seemed to influence by Maillard reaction products during the storage periods.

Development of an Efficient Simple Mass-Screening Method for Resistant Melon to Fusarium oxysporum f. sp. melonis (덩굴쪼김병 저항성 멜론을 위한 효율적이고 간편한 대량 검정법 개발)

  • Lee, Won Jeong;Jang, Kyoung Soo;Choi, Yong Ho;Kim, Heung Tae;Kim, Jin-Cheol;Choi, Gyung Ja
    • Research in Plant Disease
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    • v.21 no.3
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    • pp.201-207
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    • 2015
  • This study was conducted to establish a simple mass-screening method for resistant melon to Fusarium wilt caused by Fusarium oxysporum f. sp. melonis (FOM). Root-dipping inoculation method has been used to investigate resistance of melon plants to Fusarium wilt. However, the inoculation method requires a lot of labor and time because of complicate procedure. To develop a simple screening method on melon Fusarium wilt, occurrence of Fusarium wilt on susceptible and resistant cultivars of melon according to inoculation method including root-dipping, soil-drenching, tip, and scalpel methods was investigated. Scalpel and tip methods showed more clear resistant and susceptible responses in the melon cultivars than root-dipping inoculation method, but tip method represented slightly variable disease severity. In contrast, in the case of soil-drenching inoculation method, disease severity of the susceptible cultivars was very low. Thus we selected scalpel method as inoculation method of a simple screening method for melon Fusarium wilt. By using the scalpel inoculation method, resistance degrees of the cultivars according to incubation temperature after inoculation (25 and $30^{\circ}C$) and inoculum concentration ($1{\times}10^6$ and $1{\times}10^7conidia/ml$) were measured. The resistance or susceptibility of the cultivars was hardly affected by all the tested conditions. To look into the effectiveness of scalpel inoculation methods, resistance of 22 commercial melon cultivars to FOM was compare with root-dipping inoculation method. When the melon cultivars were inoculated by scalpel method, resistance responses of all the tested cultivars were clearly distinguished as by root-dipping method. Taken together, we suggest that an efficient simple mass-screening method for resistant melon plant to Fusarium wilt is to sow the seeds of melon in a pot (70 ml of soil) and to grow the seedlings in a greenhouse ($25{\pm}5^{\circ}C$) for 7 days, to cut the root of seedlings with a scalpel and then pour a 10 ml-aliquot of the spore suspension of $1{\times}10^6conidia/ml$ on soil. The infected plants were cultivated in a growth room at 25 to $30^{\circ}C$ for about 3 weeks with 12-hr light a day.

Optimization of Interesterification Reaction for the Continuous Production of trans-Free Fat in a Packed Bed Enzyme Bioreactor with Immobilized Lipase (고정화 리파제를 이용한 충진형 효소생물반응기 내에서의 무-트랜스 유지 연속 생산을 위한 에스테르 교환 반응의 최적화)

  • Kim, Sang-Woo;Park, Kyung-Min;Ha, Jae-Uk;Lee, Jae-Hwan;Chang, Pahn-Shick
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.173-178
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    • 2009
  • Epidemiological studies showed that high trans-fat consumption is closely associated with getting the risks of cardiovascular disease. The objective of this study was to produce trans-free fat through lipase-catalyzed interesterification, as a substitute for the cream margarine commonly used in industry. Optimum conditions for interesterification in a packed bed enzyme bioreactor (PBEB) were determined using response surface methodology (RSM) based on central composite design. Three kinds of reaction variables were chosen, such as substrate flow rate (0.4-1.2 mL/min), reaction temperature (60-70$^{\circ}C$), and ratio of fully hydrogenated canola oil (FHCO, 35-45%) to evaluate their effects on the degree of interesterification. Optimum conditions from the standpoint of solid fat content (SFC) were found to be as follows: 0.4 mL/min flow rate, 64.7$^{\circ}C$ reaction temperate, and 42.8% (w/w) ratio of FHCO, respectively. The half-life of immobilized lipase in PBEB with two stages at 60$^{\circ}C$ ($1^{st}$ stage) and 55$^{\circ}C$ ($2^{nd}$ stage) was about more than 30 days as estimated by extrapolating the incubation time course of tristearoyl glycerol (TS) conversion, whereas the half-life of the enzyme in PBEB with single stage at 65$^{\circ}C$ was only about 15 days. Finally, the results from SFC analysis suggest that trans-free fat produced in this study seems to be a suitable substitute for the cream margarine commonly used in industry.

Removal of ${\alpha}$-Gal Epitopes in Aortic Valve and Pericardium of Pig Using Green Coffee Bean ${\alpha}$-Galactosidase (돼지의 대동맥 판막 및 심낭에서 녹색콩 알파-갈락토시다아제를 이용한 알파-갈 항원결정인자 제거)

  • Park, Seong-Sik;Kim, Woong-Han;Kim, Kyung-Hwan;Lee, Chang-Ha;Choi, Sun-Young;Lee, Cheul;Oh, Sam-Sae;Kim, Kwan-Chang;Kim, Yong-Jin
    • Journal of Chest Surgery
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    • v.41 no.1
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    • pp.12-24
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    • 2008
  • Background: It is currently thought that tissue valve degeneration is related to an animal's immune response, which is mainly due to cell surface ${\alpha}$-Gal epitopes. Cell surface ${\alpha}$-Gal epitopes are known to be degraded by the enzyme called green coffee bean ${\alpha}$-Galactosidase. It is also well known that ${\alpha}$-Gal epitopes are immunologically stained by Griffonia Simplicifolia isolectin type B4. We know that many commercially available tissue valves are made of aortic valves and pericardial tissue of pig. So, we investigated whether ${\alpha}$-Gal epitopes of the aortic valve and pericardial tissue of a pig can be removed by green coffee bean ${\alpha}$-Galactosidase, and we did so by comparing immunologic staining of the tissues before and after the enzyme treatment. Material and method: After treating fresh porcine aortic valve and pericardial tissue with green coffee bean ${\alpha}$-Galactosidase at concentrations of 0.5 unit/mL, 1.0 unit/mL, 2.0 unit/mL, respectively, under the condition of pH 6.5, temperature. $4^{\circ}C$ and 24 hours of incubation, each sample was stained with Griffonia Simplicifolia isolectin type B4 immunpfluorescent labeling. We then examined whether the ${\alpha}$-Gal epitopes were reduced or abolished in each consecutive. concentration of green coffee bean ${\alpha}$-Galactosidase by comparing the degree of the Griffonia Simplicifolia isolectin B4 staining in each sample. Result: In the pig aortic valve tissue, a 1.0 unit/mL concentration of green coffee bean ${\alpha}$-Galactosidase at pH 6.5, $4^{\circ}C$ and reaction for 24 hours was enough for complete removal of ${\alpha}$-Gal epitopes from the cell sur face on the immunostaining with Griffonia Simplicifolia isolectin B4. On the other hand, more ${\alpha}$-Gal epitopes were present in the pig pericardial tissue on Griffonia Simplicifolia isolectin B4 staining before the enzyme treatment, and 1.0 unit/mL of galactosidase was not sufficient for complete removal of ${\alpha}$-Gal from the tissue. 2.0 units/mL of green coffee bean ${\alpha}$-Galactosidase was needed to completely remove the ${\alpha}$-Gal epitopes from the pericardial tissue on immunostaining. Conclusion: The ${\alpha}$-Gal epitopes of the pig's aortic valve and pericardial tissue were successfully stained with Griffonia Simplicifolia isolectin B4. We could remove nearly all the ${\alpha}$-Gal epitopes using green coffee bean ${\alpha}$-Galactosidase at the concentration of 1.0 unit/mL in the aortic valve. Of pig, and 2.0 unit/mL was need to nearly completely remove all the ${\alpha}$-Gal epitopes in the pericardial tissue of pig under the condition of pH 6.5, $4^{\circ}C$ and 24 hours of reaction time. In the near future, removal of ${\alpha}$-Gal epitapes in the pig's aortic valve and pericardial tissue will become a powerful tool for the improvement of the tissue valve durability. It needs to be determined if ${\alpha}$-galactosidase treated pig tissue is immune to human anti-Gal antibody or anit-Gal mooclonal antibodies.