Effect of process variables in supercritical carbon dioxide extraction of tocotrienols from hydrolyzed palm fatty acid distillate ( PFAD )

Abstract

In 2020, approximately 19.14 million tonnes of crude palm oil (CPO) was produced in Malaysia (MPOB, 2020). Typically, 4% (w/w) of CPO is in the form of palm fatty acid distillate (PFAD), which is recoverable as a by-product from the physical refining process (Estiasih & Ahmadi, 2018;Gapor Md Top, 2010). Fatty acids and glycerides are the major components (96.1%) of PFAD; these are commonly used in nonfood industries, within animal feed, laundry soap, biodiesel, and oleochemicals (Akinfalabi et al., 2019;Estiasih & Ahmadi, 2018;Gapor Md Top, 2010). Oil can be lost at various stages of the refining process. In addition, oil can be trapped in the by-product during palm oil milling. Consequently, vitamin E (0.48%), sterols (0.37%), squalene (0.76%), and volatile substances (0.71%) are valuable minor compo-