POLYPHENOL OXIDASE ACTIVITY IN BANANA CHIPS DURING OSMOTIC DEHYDRATION

• Published in: Drying technology Vol. 18; no. 6; pp. 1327 - 1337
• Main Authors: Waliszewski, K.N., Garcia, R.H., Ramirez, M., Garcia, M.A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.01.2000
• Subjects: Alcohols; Aromatic polymers; banana; Catalyst activity; Dehydration; Drying; Enzymes; Food processing; Musa acumiata; osmotic dehydration; Oxidation; polyphenol oxidase; Reaction kinetics
• ISSN: 0737-3937; 1532-2300
• DOI: 10.1080/07373930008917779

Various treatments were used to determine polyphenol oxidase activity changes during osmotic dehydration of banana slices. A temperature of 35 °C and 5.0 pH were used as the most adequate conditions for polyphenol oxidase activity determination when 4-methyl catechol was used as a substrate. Enzyme activity change was determined in the central and edge region of fruit. The central part of the banana slice showed 2.4 times higher activity than in the edge region. A difference in the kinetics of enzyme activity decrease also occurred during four hours of drying. When the drying was carried out at 70 °C, the enzyme was completely inactivated after 60-90 minutes of specific osmotic treatments. After four hours of osmotic drying at 50 and 60 °C, polyphenol oxidase activity was still present; the residual activity varied from 1.3 to 15 %.