Development of Phytosterol Enriched Functional Edible oils: Study of Physical, Chemical, Thermal and Structural Properties

Abstract

Phytosterol plays a major role in reducing the bad cholesterol in blood resulting in decreasing the chance of cardiovascular and other chronic diseases in human. The objective of this work was to develop a functional edible oil by incorporating phytosterol into different edible oils, such as, sunflower, soybean, rice bran, canola, and coconut oil to enhance their nutritional and functional value. In this work, thermal and structural properties of the functional oils were evaluated using Differential Scanning Calorimeter (DSC), X-Ray Diffraction (XRD) and Confocal Laser Scanning Microscopy (CLSM), respectively.
The physicochemical properties like specific gravity, color, refractive index, peroxide value, acid value and antioxidant activity of the functional oils were studied. Specific gravity, acid value and peroxide value of the functional oils increased slightly as compared to the pure oils which are within acceptable range. The antioxidant capacity of the functional oil increased from 28.85 to 98.25% due to the addition of phytosterol. Onset melting, peak melting and offset melting temperature along with the melting enthalpy were evaluated during thermal transition by using DSC. The melting temperature of the functional oils varied according to the presence of saturated and unsaturated fatty acid content. For example, a lower melting point was obtained for oils containing lower saturated fatty acids and vice versa. XRD results showed significant variations in the crystallinity values in functional oils. From the above study taking all the properties into account, functional soybean oil can be considered as the best oil for various food application due to its higher oxidative stability.