Palm-based diacylglycerol fat dry fractionation: effect of crystallisation temperature, cooling rate and agitation speed on physical and chemical properties of fractions

Abstract

Fractionation which separates the olein (liquid) and stearin (solid) fractions of oil is used to modify the physicochemical properties of fats in order to extend its applications. Studies showed that the properties of fractionated end products can be affected by fractionation processing conditions. In the present study, dry fractionation of palm-based diacylglycerol (PDAG) was performed at different: cooling rates (0.05, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0°C/min), end-crystallisation temperatures (30, 35, 40, 45 and 50°C) and agitation speeds (30, 50, 70, 90 and 110 rpm) to determine the effect of these parameters on the properties and yield of the solid and liquid portions. To determine the physicochemical properties of olein and stearin fraction: Iodine value (IV), fatty acid composition (FAC), acylglycerol composition, slip melting point (SMP), solid fat content (SFC), thermal behaviour tests were carried out. Fractionation of PDAG fat changes the chemical composition of liquid and solid fractions. In terms of FAC, the major fatty acid in olein and stearin fractions were oleic (C18:1) and palmitic (C16:0) respectively. Acylglycerol composition showed that olein and stearin fractions is concentrated with TAG and DAG respectively. Crystallization temperature, cooling rate and agitation speed does not affect the IV, SFC, melting and cooling properties of the stearin fraction. The stearin fraction was only affected by cooling rate which changes its SMP. On the other hand, olein fraction was affected by crystallization temperature and cooling rate but not agitation speed which caused changes in IV, SMP, SFC, melting and crystallization behavior. Increase in both the crystallization temperature and cooling rate caused a reduction of IV, increment of the SFC, SMP, melting and crystallization behaviour of olein fraction and vice versa. The fractionated stearin part melted above 65°C while the olein melted at 40°C. SMP in olein fraction also reduced to a range of 26 to 44°C while SMP of stearin fractions increased to (60–62°C) compared to PDAG.

Dry Fractionation Approach in Concentrating Tocopherols and Tocotrienols from Palm Fatty Acid Distillate: A Green Pretreatment Process for Vitamin E Extraction

“…Hence, at a temperature of ≤38 °C, SFA have sufficient time to crystallize, which leads to better separation. Similar findings were found in studies carried out by Ab Latip et al (2013) and Huey et al (2009). In Latip's study, iodine value (IV) was used to determine the degree of saturation in fractionated samples.…”

“…The USFA content in olein phase under slow cooling rate is 63.34% ± 2.09, which was significantly ( P < 0.05) higher than the rapid cooling rate with USFA of 58.81% ± 0.06. Comparable results were reported in a study carried out by Ab Latip et al (2013), showing the correlation between IV value of olein fraction with the cooling rate. In the mentioned study, a fast cooling rate leads to the reduction in IV value of olein fraction, demonstrating that there are more SFA in liquid fraction.…”

“…A low IV value was observed under high crystallization temperature indicated by the increment of saturation due to the increase in concentration of palmitic acid (16:0). While olein fraction with higher IV value was found at low crystallization temperature, which is mainly contributed by the presence of oleic acid (18:1) (Ab Latip et al, 2013).…”

Industrial Scale Production of Palm Super Olein using Modified and Innovative Dry Fractionation Technique

“…However, by decreasing the fractionation temperatures from 17 to 16.6 °C and in presence of 5% PO, the yields of PSO were decreased while PMF yields were increased. These results agree with that recorded by Calliauw et al, and Ablatip et al, [15,16] they found that the SF yield is strongly dependent on crystallization temperature, as crystallization temperature increased, the SF yield decreased and vice versa.…”

Characteristics of rambutan (Nephelium lappaceum L.) seed fat fractions and their potential application as cocoa butter improver

“…The results corresponded with the previous study conducted by Jin, Wang, Su et al (2017), where the yield of mango seed fat solid fractions decreased after first and second stages of fractionation due to the solid fractions became more saturated. The presence of high melting saturated fatty acids (SFAs) which were mainly arachidic and stearic acids in F 1 -S resulted in gradual precipitation of SFAs from the liquids because of the effect of low-temperature crystallization, hence more of solid fractions yielded (Latip et al, 2013). Meanwhile, the liquid fractions were found to be easily melted at <28°C due to the presence of low melting unsaturated fatty acids (USFAs) which were mainly oleic and linoleic acids causing less production of solid fractions at low temperature of crystallization process in the second stage of fractionation from F 1 -L (Jin, Wang, Su et al, 2017).…”