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.

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

“…In addition to the more "traditional" attempts on thermal modification of natural products (Fouad et al 1990(Fouad et al , 1993, recent studies have revived the use of supercritical gases for natural product extractions as capabilities of supercritical gases have been recognized for over a century (Hannay and Hokarth 1879). This technique, normally employs carbon dioxide because of its chemical inertness (Weder 1984), nonflammability, nontoxicity and that its gaseous nature does not precipitate problems associated with processing residues (Hubert and Vitzthum 1978;Randall 1982).…”

“…Thermal modification of butter oil yielded solid and liquid fractions with triacylglycerol and fatty acid compositions different from those of the starting oil only to the extent comparable to their seasonal variations (Fouad et al 1990). However, upon further modification of these fractions distinct changes in their physical properties were observed (Fouad et al 1993). Therefore, a study of the effects of SC-C02 extraction or interesterification, combined with thermal modification, was deemed necessary in order to investigate the potential of such combined modifications on butter oil.…”