The effect of ultrasound treatment on the efficiency of membrane clarification of carrot juice

Abstract

Large particles in carrot juice create a turbid appearance; therefore, membrane treatment can be used to clarify it. To evaluate the effect of ultrasound on the membrane processing efficiency, ultrasound (1,000 W, 20 kHz) was applied to carrot juice and membrane unit. Results showed that this process can increase the permeate flux by about 10–3 kg/m2s, and the rate of the increased flux caused by the ultrasound increases with increasing transmembrane pressure and feed flow rate; as, the best performance was achieved in 1 bar and 15 ml/s. Also, cake formation is the main fouling mechanism in the whole process. The total soluble solid content, pH and total phenolic compounds did not change during clarification. But, antioxidant activity (55%), total titratable acidity (47.5%), β-Carotene (59.2%) and turbidity (97.9%) were decreased. It can concluded that ultrasound can increase the efficiency of membrane processing of carrot juice due to reduce total membrane resistance. Practical applications In this study, ultrasound was applied in the membrane clarification of carrot juice, as one of the newest methods to reduce membrane fouling. The practical application of this study is that by using the cavitation phenomenon and the stress caused by the explosion of the bubbles created in this phenomenon, the large particles of the juice become smaller particles. In addition, this technology breaks down the cake on the membrane, which increases the efficiency of the membrane. This method can be used in most factories, especially in the food industry, when producing fruit juice.