Red beet stalks constitute an agro-industrial residue with potential to be utilized as betalains source. However, in order to maintain the stability of these natural pigments, it is necessary to minimize the factors that favor their degradation. The main aim of this study is the clarification of the juice extracted from beet stalks, which are rich in betalains, using microfiltration process combined with ultrafiltration. Despite the permeate flux reduction during the processes, the occurrence of fouling and betalain degradation in the permeate stream, these separation processes have been demonstrated to be efficient in clarifying the extracts. Comparing the initial extract (microfiltration feed) with the final permeate (ultrafiltration permeate), it was possible to achieve a 99.5% reduction in peroxidase activity, more than 99.9% reduction in turbidity and the color too appeared to be more intense, luminous and reddish. (C) 2016 Elsevier Ltd. All rights reserved.