Effect of monoglyceride organogel structure on cod liver oil stability

The aim of the present research was to study the influence of monoglyceride organogel structure on the oxidative stability of cod liver oil. To this purpose, organogels were prepared by mixing increasing percentages of saturated monoglycerides with cod liver oil, chosen as a natural source of polyunsaturated fatty acids. The structural characteristics of the systems as well as the kinetics of oxidation product formation were evaluated. Increasing the monoglyceride concentration, organogels show an increase of the rheological parameters highlighting different macroscopic structures. On the contrary, at nano-level the systems present the same molecular organization consisting in monoglyceride molecules crystallized in the beta-phase and self-assembled in lamellae with a width of around 46 angstrom. The presence of the monoglyceride network shows a double effect on the oxidative stability of the oil entrapped in the system. It results to be ineffective in affecting the first steps of oxidation but appears a consisting hurdle against the development of secondary oxidation product formation. These results appear interesting in the light of exploitation of organogels to structure liquid oil and thus to product novel health value-added foods. (C) 2011 Elsevier Ltd. All rights reserved.