Partial purification and characterisation of polyphenol oxidase from celery root (Apium graveolens L.) and the investigation of the effects on the enzyme activity of some inhibitors

AYDEMİR T., Akkanli G.

International Journal of Food Science and Technology, cilt.41, sa.9, ss.1090-1098, 2006 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 41 Sayı: 9
  • Basım Tarihi: 2006
  • Doi Numarası: 10.1111/j.1365-2621.2006.01191.x
  • Dergi Adı: International Journal of Food Science and Technology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1090-1098
  • Anahtar Kelimeler: celery root (Apium graveolens L.), characterisation, inhibitors, polyphenol oxidase
  • Manisa Celal Bayar Üniversitesi Adresli: Evet

Özet

Polyphenol oxidase (PPO) of celery root was extracted and partially purified by (NH4)2SO4 fractionation and dialysis. Optimum pH and temperature were found at pH 7.0 and 30°C, and Km and Vmax values were 29 mM and 5560 U mL-1 min-1 with catechol, respectively. The activation energy of the enzyme with catechol was 17.9 kJ mol-1 at pH 7.0. In electrophoretic seperation, six isoenzymes were detected with DL-dopa substrate. PPO showed activity to catechol, 4-methylcatechol, pyrogallol, gallic acid, DL-dopa. L-Tyrosine was also tested but was not oxidised by celery root PPO. β-Mercaptoethanol was found to be the most effective inhibitor. (NH 4)2SO4, NaCl, KCl and sucrose appeared to be protective agents of celery root PPO against thermal denaturation. Metal ions (Cu2+, Zn2+, Mn2+) were poor inhibitors of the celery root PPO at 1 mm. PPO activity was also inhibited by CaCl2, NaCl, BaCl2, FeSO4 and NiCl2. © 2006 Institute of Food Science and Technology Trust Fund.