Influence of Ultrasound‐Assisted Air‐Drying and Conventional Air‐Drying on the Activity of Apple Enzymes

• Published in: Journal of food processing and preservation 2017-04, Vol.41 (2), p.np-n/a
• Main Authors: Rodrigues, Sueli, Fernandes, Fabiano A.N., García‐Pérez, José V., Cárcel, Juan A.
• Format: Article
• Language: English
• Subjects: Color; Drying; Enzymes; Foods; Inactivation; Pectin; Peroxidase; Ultrasound
• ISSN: 0145-8892; 1745-4549
• DOI: 10.1111/jfpp.12832

The influence of ultrasound‐assisted air‐drying and conventional air‐drying on polyphenoloxidase, peroxidase, pectin methylestearase and peroxidase ascorbate of red apples was evaluated. Drying was carried out at temperatures of 45C and 60C, air‐velocities of 1–5 m/s, with and without application of ultrasound (30.8 W/cm3; 21.7 kHz). Both the conventional and the ultrasound‐assisted drying have increased the activity of polyphenoloxidase, peroxidase and peroxidase ascorbate in apples, while partial inactivation of pectin methylesterase was accomplished. Temperature was the main factor influencing the activity of all enzymes. Ultrasound application has influenced the activity of all enzymes, but had a more significant effect on the activity of peroxidase ascorbate. Pratical Applications Peroxidases and polyphenoloxidases are enzymes directly related to enzymatic browning in fruits. The inactivation (partial or complete) of these enzymes can provide a food product with lighter and more natural color. The inactivation of these enzymes can also preserve the amount of total phenolics in food products with direct benefit to human health. Ultrasound application showed to increase the efficiency of drying processes and to affect positively the quality of food products.