CONTROLLING OF POLYPHENOL OXIDASE-BASED BROWNING IN SELECTED FRUITS AND VEGETABLES
Amna Kausar1,2 Masroor Ellahi Babar1, Samea Khan1 and M. Sheeraz Ahmad2*
1Faculty of Science and Technology, Virtual University, Lahore, Pakistan
2University institute of Biochemistry and Biotechnology, Pir Mehr Ali Shah-Arid Agriculture University,
*Corresponding Author: email@example.com
The activity of polyphenol oxidase (PPO) lowers the nutritive qualities, and hence lower the cost of the fruits and vegetables. The present study was designed to use different physical and chemical treatments in fruits and vegetables for inactivation of PPO. The crude PPO was extracted from selected fruits (Apple, Banana, Mango, Grapes, Peach) and vegetables (Potato, Eggplant, and Lettuce) using standard protocols and PPO activity was recorded with spectrophotometer using catechol as substrate. Physical treatments were performed at 4ºC, 45ºC and 5 ºC for 20 minutes. The chemical treatments were performed using EDTA (1mg/L), ascorbic acid (0.5%), sodium chloride (1g/L), citric acid (0.75%) and honey (10% and 50%). Results indicated that PPO inhibition was maximum in banana (20.699%) at 55ºC for 20 minutes. The PPO extract from mango showed maximum inhibition (75.930%) with 50% honey. In vegetables, the PPO extract of potato showed (38.731%) inhibition at 4ºC for 20 minutes and (72.874%) with 50% honey. The results indicated that storage at 4ºC and treatment with citric acid (0.75%), ascorbic acid (0.5%) and honey (10% and 50%) were most effective for reduction of enzymatic browning in plant products. Results of this study provide bases for development of dual control strategies to prevent browning of fruits, vegetables and other food products.
Keywords: Enzymatic Browning, Polyphenol Oxidase, Peroxidase, Antibrowning