Characterization of Low Saturation Palm Oil Products after Continuous Enzymatic Interesterification and Dry Fractionation

ABSTRACT:  The lipase-catalyzed interesterification of refined, bleached, deodorized palm olein with iodine value (IV) of 62 was studied in a pilot continuous packed-bed reactor operating at 65 °C. Sn- 1,3 specific immobilized enzyme; Lipozyme® TL IM ( Thermomyces Lanuginosa ) from Novozyme A/S was used in this study. The interesterification reaction produced fully solidified fats at ambient temperature due to the production of trisaturated triacylglycerols (TAG) (PPP and PPS, where P = palmitic acid, S = stearic acid). The reaction also increased the percentage of triunsaturated TAG (OLL, OLO, and OOO, where O = oleic acid, L = linoleic acid). The interesterified product was then dry fractionated at temperatures of 9, 12, 15, 18, and 21 °C to separate the saturated fats from the unsaturated. The results show that IV of olein increased when the fractionation temperature (T_FN) decreased. The highest IV of olein was 72, obtained from T_FN at 9 °C. After interesterification and laboratory-scale fractionation, the olein fractions contained higher unsaturation content ranging from 64.7% to 67.7% compared to the starting material (58.3%), while the saturation content was reduced from 41.7% to the range of 32.3% to 35.3%. The yields of these oleins were low with the range of 24.8% to 51.8% due to the limitation of the vacuum filtration. Ten kilograms of pilot-scale fractionation with membrane press filter was used to determine the exact olein yield. At T_FN of 12 °C, 67.1% of olein with saturation content of 33.9% was obtained.