Polyphenol oxidase from Malatya apricot (Prunus armeniaca L.)

Arslan O., Temur A., Tozlu I.

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, cilt.46, ss.1239-1241, 1998 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 46 Konu: 4
  • Basım Tarihi: 1998
  • Doi Numarası: 10.1021/jf970599v
  • Sayfa Sayıları: ss.1239-1241


Polyphenol oxidase (PPO) of Malatya apricot was isolated by (NH4)(2)SO4 precipitation and dialysis. PPO showed activity to catechol, L-dopa, and gallic acid. Catechol was the most suitable substrate for Malatya apricot PPO (lowest K-m value). The optimum pH for the PPO was 8.5. Heating for 40 min at 40 degrees C did not cause a significant loss of enzymic activity. The times required for 50% inactivation of activitiy at 60 and 80 degrees C were found to be 47 and 16 min, respectively. The I-50 values of inhibitors studied on PPO were determined by means of activity percentage [I] diagrams. The values were 2.7 x 10(-5), 5.03 x 10(-5), 3.62 x 10(-5), 3.68 x 10(-5), and 8.30 x 10(-4) M for sodium metabisulfite, ascorbic acid, 2-mercaptoethanol, thiourea, and salicylic acid, respectively. Ascorbic acid, 2-mercaptoethanol, sodium metabisulfite, and thiourea inhibited the reaction strongly.