Modification of Butter Oil: Effects of Supercritical Carbon Dioxide Extraction and Intereseterification

Abstract

ABSTRACT. Physical properties of lipid fractions isolated from anhydrous butter oil under various experimental conditions using supercritical carbon dioxide (SC‐CO2) extraction, intereseterification or their combination, together with thermal modification were assayed in terms of triacylglycerol and fatty acid profiles. SC‐CO2 process, at 35C and 2000 psi, preferentially extracted the low‐molecular‐weight triacylglycerols, did not result in any separation of cholesterol and extracted an approximately constant fraction (7%) of the material in each 2h interval. Combination of SC‐CO2 extraction with thermal fractionation yielded a butter oil fraction with improved spreadability at refrigerator temperatures. At higher pressure and longer extraction time SC‐CO2 resulted in decreased solvent selectivity without increased extraction yield. The triacylglycerol and fatty acid profiles of high pressure 6000 psi extracts were remarkably similar to those of the butter itself. Chemical interesterification of butter oil randomized the constituent fatty acids, giving products which contained higher proportions of the middle‐range constituents. Thermal fractionation of interesterified butter yielded products only slightly enriched in higher molecular weight triacylglycerols, but interesterification of a solid obtained from thermal fractionation of butter gave a product greatly enriched in these compounds. Thus, modified lipid samples with distinct triacylglycerol and fatty acid compositions were prepared which may be used in different industrial applications.

Further Development in Thermal Modification of Butter Oil

“…(1985) that butter oil can be thermally modified to yield products which differ markedly in their physical and chemical properties. In brief, our earlier (Fouad et al 1990(Fouad et al , 1993 and present results suggest that thermal modification of neat butter oil or its solutions in organic solvents goes through stages characteristics to crystallization of organic substances in solutions.…”

“…In our previous work (Fouad et al 1990(Fouad et al , 1993, butter oil was thermally modified without agitation and the characteristics of solid and liquid lipid fractions assessed in terms of differential scanning calorimetry (SDC), along with triacylglycerol and fatty acid profiles assessed by HPLC and GC as a function of crystallization temperature. Under these conditions, butter oil tends to crystallize in /3' polymorphic form (Deffense, 1987;Small 1984) producing extremely small, thin needles which readily form aggregates in the oil.…”

Comparison of thermally oxidized lipids and acetaminophen with concurrent consumption of ethanol as inducers of liver cirrhosis

“…Water was removed from butter with anhydrous sodium sulfate at 60°C (Fouad et al, 1990(Fouad et al, , 1994. Similarly, in a round-bottom flask, dry butter oil (100 g) was oxidized as already described using an amount of sodium peroxide (1.6 g) related to the degree of unsaturation.…”