Authors : Malgorzata Kowalska , Witold Bekas , Eliza Gruczynska and Boleslaw Kowalski
Abstract: Mixtures of beef tallow stearin and beef tallow olein were interesterified with sunflower oil using sodium methoxide or immobilized lipases from Rhisomucor miehei (Lipozyme IM) and Candida antarctica (Novozym 435). The starting fats and the interesterified products were separated into the triacylglycerol and non-triacylglycerol fractions, which contained free fatty acids and mono- and diacylglycerols. After interesterification, the contents of free fatty acids and of mono- and diacyloglycerols increased. The slip melting point and solid fat content of the triacylglycerol fractions of the interesterified samples containing stearin and sunflower oil were lower compared with the nonesterified blends. For the interesterified mixtures containing olein and sunflower oil, the opposite dependencies for slip melting point and solid fat content were observed. The total fatty acid composition of fats before and after interesterifications remained unchanged but their distributions between sn-1, 3 and sn-2 positions were modified depending on the catalysts used. These distributions were random after chemical interesterification and close to random when Novozym 435 was used. When Lipozyme IM was used the fatty acid composition at sn-2 position remained practically unchanged compared with the starting blend.
Malgorzata Kowalska , Witold Bekas , Eliza Gruczynska and Boleslaw Kowalski , 2005. Modification of Beef Tallow Fractions by Chemical and Enzymatic Interesterification with Sunflower Oil . Journal of Food Technology, 3: 404-409.