Enzymatic modification of flax seed oil and palm based blends in the preparation of table margarine formulation
Evaluation of ternary mixtures of palm stearin (PS), palm kernel oil (PKO) and flax seed oil (FS) for their suitability as base stocks for table margarine formulations were conducted. Transesterification of the oil blends was catalysed by Lipozyme IM lipase (Novozymes, Denmark) at 45 °C, 200 rpm for 6 h. The physical and chemical properties of the transesterified oil were evaluated by slip melting point (SMP), solid fat content (SFC), differential scanning calorimetry(DSC) and high performance liquid chromatography (HPLC). In comparison with non-transesterified products, the transesterified products reduced the SMP values between 12% and 20%. All transesterified blends gave no residual SFC at 35 °C. Transesterified PS:PKO:FS blend at 54:36:10 ratio had 32% SFC at 10 °C indicating that the products had good spreadability at refrigeration temperature. DSC and HPLC analysis showed that transesterification of PS:PKO:FS with Lipozyme IM lipase had significantly reduced the high 
melting glycerides of the blends. This is reflected in the SMP values and SFC profiles of transesterified blends.
Effect of enzymatic interesterification on the melting point of tallow-rapeseed oil (LEAR) mixture
To reduce the melting point of a tallow-rapeseed oil mixture, the triglyceride composition of the mixture was altered by enzymatic interesterification in a solvent-free system. The interesterification and hydrolysis were followed by melting point profiles and by free fatty acid determinations. The degree of hydrolysis was linearly related to the initial water content of the reaction mixture. The rate of the interesterification reaction was influenced by the amount of enzyme but not much by temperature between 50 and 70°C. The melting point reduction achieved by interesterification depended on the mass fractions of the substrates: the lower the mass fraction of tallow, the larger the reduction of the melting point.
Lipase-mediated acyl-exchange reactions with butteroil in anhydrous media
Conditions optimum for porcine pancreatic lipase catalyzed acyl-exchange reactions between a free fatty acid (FFA), undecanoic acid, and butteroil in anhydrous media were established. No solvent was required for reaction, indicating that butteroil could act as dispersant as well as substrate in reactive mixtures. Optimum temperature and pH for the reaction were 70°C and 6.5 to 7.0, respectively. The addition of up to 550 mM water to reactive mixtures had little influence on the initial rates of acyl-exchange, but shifted the reaction equilibrium to favor net hydrolysis. Optimal FFA concentration for acyl-exchange was 250 mM in terms of initial reaction rates, and substrate inhibition by FFA was apparent at levels up to 1000 mM. In terms of % reaction yield and absolute reaction yield after 18 hr, 50 mM and 250 mM FFA, respectively, were optimum. Initial reaction rates for acyl-exchange between two model triacylglycerides indicated that esterified fatty acids-were better substrates than FFA under the conditions evaluated.