Membrane Performance and Potential Separation of Cytokinins During Ultrafiltration of Skimmed Coconut Milk

Coconut milk is a milky-white perishable liquid. It is enriched with complex minerals, vitamins and value-added bioproducts such as kinetin and zeatin, which are well-known as cell division promoters and commonly used in medicinal, pharmaceutical and nutraceutical application. In this study, the ultrafiltration (UF) process was used to separate kinetin and zeatin from skimmed coconut milk. The presence of kinetin and zeatin was confirmed by high performance liquid chromatography (HPLC) analysis. The ultrafiltration membranes used were 30-kDa polysulfone (PSf) and 30-kDa polyvinylidene fluoride (PVDF) membranes. Factors and mechanisms affecting the flux declines were studied and postulated. The lower normalized flux was exhibited by PVDF membrane during UF process. This showed that the extent of membrane fouling occurred on PVDF membrane compared to PSF membrane. PVDF membranes were shown to be more hydrophobic than PSf ones by contact angle tests. Morphological studies of both membranes were carried out by scanning electron microscopy (SEM). Fouling layers formed on the membranes were confirmed using SEM.