Clarification of citrus fruit juices using microfiltration technique equipped with indigenously developed novel...

Microfiltration of citrus fruit juices using membrane technology is a promising method for clarification without losing their inherent properties to extend their shelf life. The present work discusses the development of a tubular ceramic microfiltration membrane and its performance in clarifying two kinds of citrus fruit juices, mandarin and sweet orange. The membrane was prepared by the extrusion method from indigenous bentonite clay, exhibited a porosity of 37% with 0.11 μm pore size, and possessed adequate flexural strength of 18 MPa. The fabricated membrane's potential was evaluated by conducting the tangential filtration of both centrifuged and enzyme-treated centrifuged fruit juices. Also, the applied pressure (68.94-344.7 kPa) and crossflow rate (110-150 Lph) were varied to study the clarified juice properties. At low operating conditions, the highest clarity of the juices was identified despite low permeate flux. The desired properties of juices, including pH, citric acid content, and total soluble solids, were unaffected by pretreatment and tangential membrane filtration, whereas the pectin content, which reduces the juice quality, was eliminated entirely. Furthermore, fouling analysis was carried out using Hermia's models, and cake filtration was identified to be dominant for both juices.

The online version contains supplementary material available at 10.1007/s13197-023-05734-y.