Isolation and Characterization of Fuji Apple Peroxidase

사과 Peroxidase의 분리 및 특성

  • Jee, Wan-Jung (Department of Food Science, Seoul Woman's University) ;
  • Cho, Nam-Sook (Department of Food Science, Seoul Woman's University) ;
  • Kim, In-Cheol (Department of Food Science and Technology, Seoul National University) ;
  • Park, Kwan-Hwa (Department of Food Science and Technology, Seoul National University) ;
  • Choi, Eon-Ho (Department of Food Science, Seoul Woman's University)
  • 지완정 (서울여자대학교 식품과학과) ;
  • 조남숙 (서울여자대학교 식품과학과) ;
  • 김인철 (서울대학교 식품공학과) ;
  • 박관화 (서울대학교 식품공학과) ;
  • 최언호 (서울여자대학교 식품과학과)
  • Published : 1991.08.01

Abstract

Three peroxidase fractions (peak I, II, III) were isolated from Fuji apples using CM-cellulose chromatography. The homogeneity of the isolated peroxidase isozymes was established by isoelectric focusing and electrophoresis. Isoelectric points of the isozymes were 3.80, 3.82, and 3.85, respectively. The optimum pH of peroxidase isozymes were pH 5.0(peak I) or 5.5(peak II, III), and optimum temperature was $40^{\circ}C$ when assayed by using guaiacol and $H_{2}O_{2}$ as substrates. Inactivation rate of three peroxidase isozymes were different at temperature of $70^{\circ}C$ and at pH of 5.5. The isozyme of peak II was found to be more heat stable than those of peak I and III. D values at $70^{\circ}C$ of peroxidase isozymes (peak I, II, III) were estimated to be 660 sec, 1,320 sec, and 600 sec, respectively. The thermal stability of Fuji apple peroxidase was not influenced in the presence of 0.032 M sucrose or lactose. However, the thermal stability of the enzyme was decreased by fructose and glucose.

Keywords

apple peroxidase;isolation of enzymes;thermal stability;isozymes