Volume 4, Issue 3 (March 2007)
Thermal and Oxidative Properties of Physiologically Relevant Free Fatty Acids by Dielectric Analysis and Differential Scanning Calorimetry
Physiologically relevant fatty acids and related organic acids are basic for human life. The essential fatty acids, linoleic, linolenic, and arachidonic acids, are sourced from vegetable seed oils (corn, sunflower, safflower), and margarines blended with vegetable oils. The functions of these special acids are in the synthesis of prostaglandins and membrane structures. Growth cessation and dermatitis occurs with a deficiency of the fatty acids. A typical therapeutic dosage of the essential fatty acids is up to 10 g per day. The polyunsaturated fatty acids. linoleic (9,12-octadecaidienoic), linolenic (9,12,15-octadecatrienoic), and arachidonic (5,8,11,14-eicosatetraenoic) are referred to as essential fatty acids. They unlike other lipids must be provided by diet. Arachidonic acid can be produced in the body by linoleic acid. This thermal analytical study is to determine fatty acids’ physical transitions [melting] by DSC at low temperatures and their surface properties by low frequency dielectric analysis and relate those properties to the inherent amount of unsaturation in the fatty acids. It is our premise that the degree of unsaturation will affect low temperature melt temperature and electrical properties, e.g., electrical conductivity and complex permittivity. We have observed that the DEA properties of the air-aged liquid fatty acids indicate that the electrical conductivity and complex permittivity can be correlated with the degree of unsaturation. It is our objective to establish a relationship between the amount of unsaturation, number of double bond sites and the electrical properties, complex permittivity, and electrical conductivity.