FURTHER DEVELOPMENT IN THERMAL MODIFICATION OF BUTTER OIL

Abstract

ABSTRACT.Anhydrous butter oil was modified by acetone or n‐hexane crystallization (10–20% w/w) over a temperature range of 29–17C without agitation, producing solid fractions with higher proportions of C44–C54 triacylglycerols vis‐a‐vis fractions obtained by classical thermal modification of butter oil. Similarly, recrystal‐lization of a mixture of thermally isolated butter oil solids (S.25–S. 17C) in organic solvents at various temperatures yielded butter lipid fractions with significantly distinct chemical and physical properties. These lipid fractions showed to contain higher and lower proportions of C44–C54 and C26–C36 triacylglycerol respectively vis‐a‐vis solid fractions isolated via thermal modification of butter oil in organic solvents as the starting material(S.25–S. 17C) contained more of the former and less of the latter triacylglycerols than butter oil.Extraction of low molecular weight lipidsfrom solid fractions obtained by classic thermal modification of butter oil using acetone left a white powderous lipid which produced one sharp melting peak (53 C) in its DSC thermogram. The acetone treated fraction was enriched in C44–C52 triacylglycerols with a 2 to 6‐fold reduction in C4–C10 fatty acids content.Recrystallization of a mixture of solid butter fractions isolated according to classical procedures at 29–21 C, over a temperature range of 35–21 C, yielded discrete fractions with profound differences in fatty acid and triacylglycerol profiles having very distinct physical properties.