A CRITICAL-EVALUATION OF THERMAL FRACTIONATION OF BUTTER OIL

Butter was fractionated on the basis of temperature (17-29-degrees-C) without agitation using slow cooling of melted anhydrous fat in conjunction with gentle vacuum filtration to produce four solid and four liquid fractions. Each of the fractions was analyzed for fatty acid composition, triglyceride profile, and characterized by gel permeation high performance liquid chromatography and differential scanning calorimetry thermograms. Fatty acid analysis indicated that the solid fractions had slightly higher amounts of palmitic and stearic acid and lower levels of oleic acid, while the remaining analyses did not indicate any substantial compositional differences between the fractions. Although the 29-degrees-C solid fraction (approximately 10%) could be said to be somewhat unique, the natural variation in the normal seasonal composition of butterfat was almost equal to that obtained by fractionation. The experimental physicochemical data obtained for the fractions in this study extend and verify previous work on butteroil fractionation, and indicate that thermal fractionation has marginal merit. On the other hand, literature describing more positive thermal butteroil fractionation results obtained by the proprietary Tirtiaux process (Fleurus, Belgium), indicates that it may be a more expedient avenue to explore and let market forces determine whether fractionation has a future in Canada and North America.