Blending of supercritical carbon dioxide (SC-CO 2) extracted palm kernel oil fractions and palm oil to obtain cocoa butter replacers

Abstract

Palm kernel oil (PKO) was fractionated into four fractions using supercritical carbon dioxide (SC-CO 2) denoted as f-PKO (f-PKO-1, f-PKO-2, f-PKO-3 and f-PKO-4). The f-PKO-3 and f-PKO-4 were denoted as low lauric (C 12) and high oleic (C 18:1) constituents which were blended with conventionally extracted palm oil (PO) and fatty acid supplements of commercial C 18:0 and commercial C 18:1 constituent at different ratios to obtained cocoa butter replacers (CBRs) to define 10 blends. The C 12 was reduced to 17.9% and C 18:1 was increased to 37.8% in the blends referred to f-PKO-3 as a blend component. Whereas referred to f-PKO-4 as a blend component the C 12 was reduced to 14% and C 18:1 increased to 38.4%. Although C 18–C 14 remain and C 18:0 constituent was still lower than that of commercial cocoa butter (CB) in some blends, it did not affect other physico-chemical properties, especially to slip melting point (SMP) and solid fat content (SFC). However, the remaining C 12 and C 14 of blends 1–10 could be reduced by further blending with commercial CB or milk fat to use as non-C 12 CBRs or could be used as low C 12 content CBRs in chocolate product and coating materials. In blend 1 (referred to f-PKO-3 and f-PKO-4 as blend components) where SMP was higher than commercial CB, thus, the SFC value did not drop to 0% at 37.5 °C. In referring f-PKO-3 and f-PKO-4 as blend components the SMP and SFC from blends 2–10 were found to be closer to that of commercial CB. SFC of the blends 2–10 was found to be higher at 20 °C and 0% at 37.5 °C. The other properties like iodine value (Iv), saponification value (Spv) and acid value (Av) for the blends 1–10 were found to be closer to that of commercial CB. From analysis of 10 blends the blending ratios were correlated with multiple linear regression equation and it was found that there was a strong relationship with the fatty acids constituents, SMP, Iv, Spv, Av and SFC. All blends were found to be able to use as CBRs.