6 - Membrane Filtration Processes for the Treatment of Nonalcoholic Beverages

Abstract

Extraction, purification, and concentration of high added-value compounds from natural sources are of great interest to pharmaceutical and food industries. Several beverages, including fruit juices, teas, and others, present high concentration of bioactive compounds that should be extracted, fractioned, and concentrated. This treatment can be understood in terms of five stages: macroscopic pretreatment, macro- and micromolecules separation, extraction, isolation and purification, and product formation. Optimal extraction conditions have been investigated and alternative processes, such as ultrasound-assisted extraction, are reported to improve the extraction of target compounds. The choice of suitable and eco-friendly solvents is also important especially for food applications. Membrane filtration processes are an alternative for purification and concentration of bioactive compounds from liquid extracts, since the process is carried out at low temperatures and preserves the food functional nutrients with a minimal energy demand. However, the process presents some drawbacks that should be considered, such as the membrane fouling and the choice of appropriated membrane material and configuration. This chapter focuses on the application of membrane filtration processes for the clarification of nonalcoholic beverages and the sequential isolation and purification of high added-value compounds from these beverages, by evaluating the quality of the obtained products. An overview of the nonalcoholic beverages that presents high concentration of bioactive compounds is presented. Particular emphasis is given to the membrane process conditions, including the choice of operation conditions and of membrane materials and configurations. Finally, the process modeling is discussed to better understand the fouling occurrences and to propose alternatives for its minimization.