Partial purification and thermal characterization of peroxidase from okra (Hibiscus esculentum)

Yemenicioglu A., ÖZKAN M., Cemeroglu B.

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, vol.46, no.10, pp.4158-4163, 1998 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 46 Issue: 10
  • Publication Date: 1998
  • Doi Number: 10.1021/jf980456o
  • Journal Name: JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.4158-4163
  • Keywords: peroxidase, okra, partial purification, thermal characterization, substrate specificity, SODIUM DODECYL-SULFATE, POLYPHENOL OXIDASE, APPLE POLYPHENOLOXIDASE, HIGH-TEMPERATURES, HEAT-TREATMENT, SWEET CORN, INACTIVATION, LIPOXYGENASE, REGENERATION, ACTIVATION
  • Ankara University Affiliated: Yes

Abstract

Thermal characteristics and substrate specificity of peroxidase (POX) from okra were determined. Crude POX was separated into eight fractions (P1-P8) by DEAE-cellulose chromatography. Heat inactivation of POX was biphasic and fitted to a first-order kinetic model. Inactivation rates of crude POX and eight POX fractions at 70 degrees C varied between (63.499 and 123.809) x 10(-2) min(-1) for the heat-labile fractions and (11.255 and 31.441) x 10(-2) min(-1) for the heat-stable fractions. Activation energies for the inactivation of crude extract were 37.0 kcal mol(-1) with a z-value of 13.8 degrees C for the heat-labile fraction and 37.8 kcal mol(-1) with a z-value of 13.5 degrees C for the heat-stable fraction. Optimum temperatures were between 30 and 35 degrees C for the crude extract, 60 degrees C for P1-P5 fractions, and more than 65 degrees C for P6-P8 fractions. Among substrates, guaiacol was oxidized primarily by P1-P6 fractions; whereas, pyrogallol and catechin were preferred by P7 and P8, respectively.