Enzymatic interesterification of beef tallow/coconut oil blends to produce a superior margarine base stock

The effect enzymatic interesterification (EIE) on the functional performances of beef tallow (BT) blended with coconut oil (CO) in varying proportions was investigated. BT and three different proportions of CO, containing 20%, 30% or 40% CO were interesterified in a solvent-free system with a commercial immobilised lipase, Lipozyme TL IM. The interesterified oils (IOs) were also processed into margarines, and their textural properties, microstructure as well as their sensory properties, were determined. The IO with 40% CO has the best properties for margarine production, with a low content of high melting-point triacylglycerols, which should minimise the 'waxy' mouth-feel of BT-based margarines. The fat in IO-based margarine (M-IO) was mainly in the beta ' crystal form and the crystals were more evenly distributed than in BT-based margarine (M-BT). A sensory and textural evaluation determined that the texture of M-IO was more compact, and that its colour and flavour were better than M-BT. The IO obtained may be used as a base oil to replace BT in margarine and has potential application in the margarine industry.