Thermal stabilities of peroxidases from fresh pinto beans

Yemenicioglu A., ÖZKAN M., Cemeroglu B.

JOURNAL OF FOOD SCIENCE, vol.63, no.6, pp.987-990, 1998 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 6
  • Publication Date: 1998
  • Doi Number: 10.1111/j.1365-2621.1998.tb15839.x
  • Journal Name: JOURNAL OF FOOD SCIENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.987-990
  • Keywords: peroxidase, pinto beans, heat activation, heat inactivation, purification, POLYPHENOL OXIDASE, APPLE POLYPHENOLOXIDASE, HORSERADISH-PEROXIDASE, INACTIVATION KINETICS, HEAT INACTIVATION, ISOENZYMES, VEGETABLES, PURIFICATION, ASPARAGUS, RESISTANT
  • Ankara University Affiliated: Yes

Abstract

Heat stabilities of crude and partially purified soluble (SPOX), ionically bound (IPOX) and total peroxidase (TPOX) from fresh pinto beans were investigated at 55-90 degrees C, Heat inactivation of peroxidase (POX) followed first-order reaction kinetics. Each inactivation curve consisted of two linear parts: initial rapid inactivation (heat-labile) followed by slower inactivation (heat-stable). IPOX showed activation during heat treatment with a highly heat-stable isoenzyme (D-90=40 min) which was more heat-stable than SPOX. Activation energies for heat-stable parts of crude IPOX and SPOX were, respectively, 12.1 and 36.4 kcal.mol-1 with z values 45.4 and 14.1C degrees. Heat stable SPOX isoenzymes (D-70=22.6) were obtained by 65-95% (NH4)(2)SO4 precipitation from crude SPOX. Two POX fractions (F1 and F2) were separated from TPOX by ion-exchange chromatography.