Liquid‐liquid phase separation in acetone solutions of palm olein: Implications for solvent fractionation

Abstract

The quality of palm mid fractions (PMF) obtained by dry fractionation has increased, but the best-quality PMF for application in many confectionery fats are still produced by solvent fractionation. In the present study, liquid-liquid phase separation has been observed in acetone solutions both for pure triacylglycerols and for palm olein. The temperature at which phase separation occurs increases as the oil concentration is increased and linearly as the water content of the system is increased. The triacylglycerol compositions of the two liquid phases that form do not differ. However, the oil-rich phase is depleted with respect to the polar components. The temperature at which liquid-liquid phase separation occurs is reduced by about 0.2 and 0.4 7C per percent of free fatty acids and diacylglycerols, respectively. When oil-rich droplets appear, crystallisation occurs within them rather than in the oil-depleted phase, due to the higher oil concentration. Thus, liquid-liquid phase separation prior to crystallisation raises the nucleation temperature but may lead to a greater concentration of entrained olein in the filter cake, leading to a poorer-quality PMF.

Understanding the Roles of Oiling-out on Crystallization of β-Alanine: Unusual Behavior in Metastable Zone Width and Surface Nucleation during Growth Stage

“…Figure demonstrates the formation of oil droplets prior to crystal nucleation and that crystal nuclei form initially in the oil droplets. The similar observation was also found in many other cases. ,,, …”

“…The similar observation was also found in many other cases. 7,15,33,34 Therefore, it can be speculated that solvent environment of nucleation in oiling-out crystallization is related to the solvent composition in the oil droplets instead of that in the overall solution. 14,35 Thus, broadening of metastable zone widths under high temperatures may be rationalized that the change in binary solvent compositions leads to the difficulty in nucleation within oil droplets.…”

Investigation of the effect of liquid–liquid phase separation (LLPS) on nucleation and different growth stages of vanillin and bulk growth of defect-free single crystals from aqueous solution – a new approach

“…has been studied. [6][7][8][9][10][11][12][13][14][15][16] Bulk growth of vanillin single crystals from solvent mixtures of chloroform-methanol, chloroformacetone and chloroform and from melt growth processes has already been reported by a few authors. 2,[17][18][19] So far, no report in the literature has been found on the growth of bulk vanillin single crystals from pure aqueous solution and on the metastable zone width (MSZW) of vanillin aqueous solution.…”

Crystallization of Pharmaceutical Crystals

“…For instance, this type of phase diagram is observed and described for the emulsification and crystallization of lauric acid in an ethanol-water mixture [74]. This type of phase diagram is often observed in protein systems [75][76][77]; however, a few cases are documented for small molecules [78][79][80][81][82][83][84][85]. And (3), with shorter range attractions, the gas-liquid or liquid-liquid equilibrium becomes metastable.…”