Structural, rheological and thermal properties of crude palm oil obtained in pressed, sifted and clarification stages using ultrasound-assisted

Abstract Crude palm oil (CPO) is commonly used in the oil industry. This study presents a comparison of the structural, rheological, and thermal properties of clarified CPO (CCPO) sample obtained using the conventional method and ultrasound-assisted (UA)-treated samples. These samples were obtained in the pressed (press liquor, PL), sifted (sifted liquor, SL), and clarification (outlet sludge, OS) stages. The frequencies used for the UA-treated samples were 40 and 80 kHz for 30 min. The PL and SL samples exhibited higher resistance to oxidative deterioration and nutritional quality than the CCPO sample did. The maximum oil extractability percentage (OEP) of the UA-treated samples relative to that of CCPO was 7.4 %. The bleachability index (DOBI) values of the UA-treated samples were higher (between 2.06 and 2.58) than that of the CCPO sample (1.43). However, the viscosity ( η ) displayed opposite trend. The thermal stability did not exhibit consistent patterns with increasing frequency.