Pomegranate (Punica granatum L., Punicacea) is a native fruit in Middle East that has several nutritional benefits, such as the prevention of cancer and heart disease (Salehinia, Mirsaeedghazi, & Khashehchi, 2021). The pomegranate juice is a non-cloudy texture in which anthocyanins, tannins and ellagic acid are the main phenolic components (Salehinia et al., 2021). On the other hand carrot (Daucus carota L.) that is cultivated all over the world, is rich in β-carotene, which makes it an excellent source for provitamin A in the human diet (Stinco et al., 2019). Carrot juice, which has a cloudy texture caused by large particles, is an important source of bioactive compounds such as carotenoids (Cakmak & Ozyurt, 2021; Shakeel, Aslam, Shoaib, Sikandar, & Ramzan, 2013).

Pomegranate and carrot juices should be clarified before their concentration in order to avoid the production of unfavorite taste caused by the burning of large particles that stick to the wall of evaporator during the concentration process (Hemmati, Mirsaeedghazi, & Aboonajmi, 2021; Sharifanfar, Mirsaeedghazi, Fadavi, & Kianmehr, 2015). Traditional clarification methods use enzymes (pectinase and amylase) and fining agents such as gelatin and bentonite. They are time-consuming and labor-intensive processes that require expensive enzymes. Also one of the main concerns is the incomplete removal of additives (fining agents and filter aids) from the final product, which can affect the flavor of the juice (Bhattacharjee, Saxena, & Dutta, 2017; Mirsaeedghazi, Emam-Djomeh, Mousavi, Aroujalian, & Navidbakhsh, 2010).

Nowadays, membrane processes such as microfiltration (MF) and ultrafiltration (UF) are used for clarification of fruit juices due to their low labor requirements, short process time, high efficiency, and thus considerably lower operating costs compared to conventional clarification methods (Cassano, Conidi, & Drioli, 2010; Nourbakhsh, Emam-Djomeh, Mirsaeedghazi, Omid, & Moieni, 2014). But fouling is a limiting phenomenon that prevents the industrialization of membrane clarification of fruit juices (Aliasghari Aghdam, Mirsaeedghazi, Aboonajmi, & Kianmehr, 2015; Yousefnezhad, Mirsaeedghazi, & Arabhosseini, 2017).

Several techniques such as laser (Salehinia et al., 2021), ultrasound waves (Aliasghari Aghdam et al., 2015), membrane filtration using rotating disk module (Zhu et al., 2013), centrifugation (Yousefnezhad et al., 2017) and scraped-surface membrane unit (Yassari, Mirsaeedghazi, Roozbeh Nasiraie, & Fadavi, 2023) were used to reduce membrane fouling. For the first time, Yassari et al. (2023) designed a scraped surface membrane unit in which blade rotation was used to increase flow turbulence and thus reduced concentration polarization and fouling phenomenon. They used this unit to clarify apple juice (Yassari et al., 2023).

Pomegranate and carrot juices, like other juices, should be clarified before concentration, but the presence of suspended particles in these juices causes fouling phenomenon in the membrane clarification process. Therefore, finding a suitable method to reduce this disturbing phenomenon in the process has been the subject of study by researchers in recent years. Previous studies conducted on the new scraped surface system showed that this system can have a positive effect in reducing the fouling phenomenon in membrane processes, but the difference between these juices raised the question, for which one is this system more effective? In other words the different textures of pomegranate and carrot juices (non-cloudy and cloudy texture, respectively) created uncertainty about the effectiveness of blade rotation on the membrane clarification efficiency of these two juices with scraped surface membrane unit. Therefore, the present research was designed to answer this question, in which a scraped surface membrane unit was used to clarify carrot and pomegranate juices at different pressure, flow rate and blade rotation speeds and the efficiency of processes were compared.