Reverse osmosis (RO) and forward osmosis (FO) are nonthermal membrane technologies gaining attention in the food industry due to their ability to concentrate liquid foods while having limited effect on the physicochemical and sensory characteristics of the product. Red beetroot juice (BRJ) is a promising candidate for this type of processing, as it contains essential bioactive compounds that are susceptible to thermal degradation. Nevertheless, membrane fouling and concentration polarization are two challenges that can limit concentration efficiency and decrease compounds of interest, in both RO and FO.The first objective of this work was to evaluate the concentration efficiency of BRJ using RO and FO as single processes, focusing on permeate flux behavior, color, and betalain retention. A RO-FO combination process was then explored, with the goal of improving process performance. For FO concentration, potassium citrate was used as an osmotic agent. Both the single-process and combination approaches were first conducted on single strength BRJ obtained by diluting thermally concentrated juice (TCJ) and then validated with freshly extracted juice (not from concentrate, NFC). RO concentration plateaued at 17.3 ± 0.4 ºBrix for the TCJ and at 12.3 ºBrix for the NFC, while FO was able to reach values of 50.9 ± 2.9 ºBrix and 49.7 °Brix, and showed a more stable flux behavior. There were no significant changes (p > 0.05) in color parameters and betalain retention in all the TCJ samples, while NFC juice experienced a 5% decrease in the betacyanin content after RO and FO concentration and a shift in red color towards green and blue hues was observed. There was also a significant increase in pH and a decrease in titratable acidity after FO concentration, which was attributed to reverse solute flux (RSF) from the osmotic agent to the feed side, demonstrated by the increase in citrate concentration in the juice. The combined RO-FO process was successful in terms of quality retention but did not present additional benefits regarding instant permeate flux and achievable concentration factor compared to FO concentration alone. Overall, the results of this work indicate that FO is a promising option for the concentration of thermosensitive foods like BRJ, although strategies to reduce RSF are necessary. The second objective of this research was to evaluate microfiltration (MF) as a mitigation strategy to reduce membrane fouling during RO concentration of coffee. Instant coffee was reconstituted to 10 °Brix and microfiltered with a 0.45-micron pore size ceramic membrane, and subsequently RO concentrated using an MMS Triple System bench top RO system. Water flux and particle size distribution were assessed to evaluate MF effectiveness as a pretreatment. Results suggested that high shear stress during MF and RO caused particle size agglomeration in coffee, increasing membrane fouling and therefore reducing concentration performance. This shows that MF is not an effective pre-treatment for minimizing membrane fouling during RO of coffee, although this strategy was shown to be effective for other liquid foods.