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.
Enzymatic interesterification of tallow-sunflower oil mixtures
In an effort to improve the physical and/or thermal characteristics of solid fats, the enzymatic interesterification of tallow and butterfat with high-oleic sunflower oil and soybean oil was investigated. The two simultaneously occurring reactions, interesterification and hydrolysis, were followed by high-performance liquid chromatography of altered glycerides and by gas-liquid chromatography of liberated free fatty acids. The enzymes used in these studies were immobilized lipases that included either a 1,3-acyl-selective lipase or acis-9-C18-selective lipase. The degree of hydrolysis of the fat/oil mixtures was dependent upon the initial water content of the reaction medium. The extent of the interesterification reaction was dependent on the amount of enzyme employed but not on the reaction temperature over the range of 50–70°C. Changes in melting characteristics of the interesterified glyceride mixtures were followed by differential scanning calorimetry of the residual mixed glycerides after removal of free fatty acids. Interesterification of the glyceride mixes with the two types of enzymes allowed for either a decrease or increase in the solid fat content of the initial glyceride mix.
Practical, legal, and ethical issues in expanded access to investigational drugs.
The authors review the FDA policies and procedures that permit some patients with serious conditions to receive investigational drugs before formal product approval and examine the legal and ethical issues associated with expanded access.