Document Type : Original Paper

Authors

• Z. Kouchak yazdi ¹
• I. Alemzadeh ²

¹ Ph.D. Student, Department of Food Chemical Engineering, Faculty of Chemical and Petroleum Engineering, Sharif University of Technology

² Professor, Department of Food Chemical Engineering, Faculty of Chemical and Petroleum Engineering, Sharif University of Technology

Abstract

Mixtures of palm and sunflower oils with different compounds of 80:20, 60:40, 50:50, 40:60, 20:80 were inter-esterified. For this purpose a special stabilized lipase (Lipozyme TLIM) was used and the physicochemical properties were determined as following: free fatty acids content, peroxide value, iodine value, slip melting point, solid fat content, P-anisidine value, soap, oxidative stability at 110 ⁰C, and the profile of fatty acids on the primitive blends and final samples after esterification processes. The inter-esterification reactions were done by addition 6% enzyme to blend and reactions were done at 70 ⁰C for 4 hours. Esterification caused to decrease in oxidative stability, solid fat content, slip melting point, peroxide value and increase in P-anisidine value, soap and free fatty acids. The blend of palm and sunflower oils with different percentages had saturated and unsaturated by and from fatty acids in ranges of 37.6-52%, 48-62.4% respectively. Loss of oil is the most important issue in inter-esterification process of oils and fats; so the optimization of the process was studied to produce the minimum free fatty acids content and to minimize loss of the oil. The optimum condition for minimizing the fatty acid in oil under the condition at 65 ⁰C and using 7.5 percent enzyme for 4.5 hours reaction was obtained. Also the statistical studies of fatty acids blends before and after reaction for 50:50  ratio of the used oils showed that the esterification process has no effect on fatty acid structure of the blends.

Keywords

• Inter-esterification
• Lipase
• Palm oil
• Physicochemical properties
• Sun flower oil