Conjugated linoleic acids (CLAs) are a group of positional and geometrical isomers of linoleic acid with a conjugated double system. The major natural sources of CLA are fat tissues of ruminants (meat and dairy products). Vegetable oils contain small amounts of CLA (0.1-0.5 mg/g fat) which is formed as a result of industrial processing; oil refining processes (mainly deodorization) and catalytic process of hydrogenation. Even though CLA ( cis 9, trans 11 and trans 10, cis 12) has beneficial effects, such as inhibiting tumor growth, reducing atherosclerotic risk and reducing body fat, the consumption of dietary CLA has decreased during the past 20 years due to the replacement of milk and animal fats by vegetable oils. It is suggested that relatively low amounts of CLA (3.5 g/d for a 70-kg person) in human diet would have an anticarcinogenic effect. However, to the best of our knowledge, there are still no reports on the production of food products enriched by CLA. In this study, two important isomers of CLA, were produced up to 73% of total fatty acids employing alkali isomerization of safflower oil, followed by purification with only one-step urea crystallization to 85.6%. The results showed that CLA purification with compounds such as urea and ethanol which are friendly to environment is practical to remove other fatty acids and increase CLA concentration. Interesterification (acidolysis) of purified CLA with canola oil was then conducted by lipase enzyme. The CLA content incorporated to the Structured lipid (SL) was 26.6 mol % after 48h of reaction time. Physicochemical properties of the SL were then changed according to the degree of substitution of oleic acid in canola oil with CLA. Palm stearin (PS) is the solid fraction produced from palm oil by fractionation and has limited usage due to its high melting point (44-56 o C). The liquid fraction is known as palm olein and is more expensive than PS due to wider usage. Regarding to hydrogenation defects, PS is a natural source of hard component and devoid of trans fatty acids for products such as margarine and shortening. In this study, SL containing CLA, was blended with PS in different ratios and analyzed for physicochemical properties. Based on SMP, SFC, DSC, XRD results, the interesterified blend of PS/SL 40:60 was selected for the formulation of margarine. The oil phase of margarine contained no trans fatty acids and about 10.6% of CLA which is several times higher than the natural content of CLA in milk. Physical properties of experimental margarine were evaluated by SFC, hardness, dropping point, crystal form and rheology. The results showed that the margarine is plastic and spreadable. The predominant crystal form is ?’. Regarding to rheological data, margarine was a viscoelastic food and exhibited pseudoplastic behavior with presence of a yield stress. The effects of three-month sto
