Synthesis of Linoleic Acid of Conjugated Isomers from Sesame (Sesamum Indicum) Seed Oil: Its Use and Effect in a Microstructured Product Type Oil-in-Water Emulsion

David Ramírez-Brewer, Luis Madrid-Palencia, Luis Monroy-Rodríguez, Somaris Quintana-Martínez, Luis A. García-Zapateiro *

¹Research Group of Complex Fluid Engineering and Food Rheology, University of Cartagena, Cartagena, Colombia

²Departamento de Operaciones Unitarias. Facultad de Ingeniería. Grupo de Investigación Ingeniería de Fluidos Complejos y Reología de Alimentos (IFCRA). Universidad de Cartagena. Cartagena de Indias. Colombia.

Corresponding Author E-mail: lgarciaz@unicartagena.edu.co

The development of functional foods is an area of great interest and innovation in the food industry. The use of conjugated linoleic acid (CLA) in food formulations has been growing in recent years due to its multiple health benefits. In this study, conjugated linoleic acid was obtained from sesame oil, and its use in the formulation of oil-in-water food emulsions was evaluated. Conjugated linoleic acid (CLA) was synthesized from the linoleic acid present in sesame oil using the alkaline isomerization method using proplyeneglycol as a solvent. The effect of alkali concentration (NaOH) and reaction time on the conversion of linoleic acid to CLA was evaluated. A 96.6% conversion of CLA was obtained with a NaOH concentration of 7% and a reaction time of 2 h. Emulsions were prepared using CLA as oil phase and soy lecithin, tween 80, carboxymethylcellulose as emulsifying agents. Emulsions with mixtures of carboxymethylcellulose and tween 80 were stable, presenting a non-Newtonian fluid behavior of pseudoplastic type (n<1). The Ostwald-de-Waele model shows an optimal fit to the experimental data of apparent viscosity (R²>0.99 ), and its microstructural characterization shows a homogeneous particle distribution. These results show that the alkaline isomerization process using propylene glycol as a solvent is an excellent alternative for the synthesis of CLA from vegetable oils such as sesame oil and its application in the development of microstructured products such as functional emulsions, and their subsequent application in the development of new food products with beneficial health characteristics.

Conjugated linoleic acid; Emulsions; Microstructure; Ostwald-de-Waele model; Rheology; Sesame oil

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