Interesterification of Butter Fat by Lipase fromMucor mieheiin Organic Solvent Media

Summary Butter fat was interesterified in three organic solvent media, hexane, hexane‐chloroform (70:30, v/v), and hexane‐ethyl acetate (70:30, v/v), at different water contents, using commercial immobilized lipase from Mucor miehei. The results indicate that the addition of 30% of either chloroform or ethyl acetate to the hexane resulted in a 25% increase in the interesterification yield; moreover, the addition of 0.8 to 1% water shifted the hydrolytic affinity of lipase towards low molecular weight fatty acids. However, the addition of a small portion of water in hexane, 0.4%, increased the amount of free fatty acids from 0.30 to 7.98 mmole per gram of butter.