Use of Nanomaterials as Alternative for Controlling Enzymatic Browning in Fruit Juices

Abstract Polyphenol oxidase (PPO) enzyme, present in most of fruits and vegetables, frequently induces browning in juices and beverages during postharvest and processing. Many efforts have been done to prevent or avoid this reaction. Nevertheless, the development of new methods is still of interest since many of the current methods present important drawbacks. An overview of the exiting techniques to inhibit enzymatic browning has been compiled in this chapter, including physical (i.e., thermal treatments, high pressures, irradiation, ultrasonication, pulsed electric fields, and ultrafiltration) and chemical techniques (acidification, addition of antibrowning agents) but with particular attention to those based on nanomaterials. The latter includes diverse approaches such as the immobilization of enzymes in nanomaterials, their incorporation as recognition or transducers elements in biosensors, or the use of silver nanoparticles. Finally, recent advances in the use of mesoporous materials to inhibit enzymatic browning in fruit juices have been discussed.