Heat inactivation kinetics of apple polyphenoloxidase and activation of its latent form

Yemenicioglu A., ÖZKAN M., Cemeroglu B.

JOURNAL OF FOOD SCIENCE, cilt.62, sa.3, ss.508-510, 1997 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 62 Sayı: 3
  • Basım Tarihi: 1997
  • Doi Numarası: 10.1111/j.1365-2621.1997.tb04417.x
  • Dergi Adı: JOURNAL OF FOOD SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.508-510
  • Anahtar Kelimeler: polyphenoloxidase, apple, latent PPO, heat activation, heat inactivation, MUSHROOMS AGARICUS-BISPORUS, CATECHOL OXIDASE, PURIFICATION, INHIBITION, JUICE
  • Ankara Üniversitesi Adresli: Evet

Özet

Heat inactivation kinetics of crude polyphenoloxidase (PPO) from six apple cultivars (Golden Delicious, Starking Delicious, Granny Smith; Gloster, Starcrimson and Amasya) were studied at three temperatures (68 degrees, 73 degrees and 78 degrees C). PPO activity initially increased and then decreased with heat, following a first order kinetic model. Increase in activity indicated presence of latent PPO. Regression coefficients for the linear portions of inactivation curves were computed to determine inactivation parameters. Reaction data at 78 degrees C revealed that PPO in Amasya was the least and Starking Delicious the most heat-stable. Rate constants for heat inactivation at 78 degrees C ranged from 15.99-28.27.10(-2) min(-1). Activation energies varied between 54.7-77.2 kcal.mol(-1) with z values of 7.1-10.0C degrees. PPO in apples was generally more heat-stable than PPO in most fruits.