Food industry is increasing its interest in formulating biocompatible microemulsions to be used as reservoirs of bioactive substances. The structural characterization of such systems is of great importance, as their physicochemical properties govern their capacity for encapsulation and delivery of bioactive components.
The aim of this work was to formulate a food grade microemulsion based on medium chain triglycerides, isopropyl myristate, lecithin, ethanol and glycerol in order to encapsulate different antioxidant molecules and a subsequent comparative assessment of their antioxidant activity.
Structural characterization of the proposed system was obtained using Dynamic Light Scattering (DLS), Electron Paramagnetic Resonance (EPR) spectroscopy using the spin probing technique [1], and Cryogenic-Transmission Electron Microscopy (Cryo-TEM).
Moreover, the microemulsions loaded with antioxidants were studied for their free radical scavenging capacity [2]. A comparative assessment of a series of encapsulated antioxidants showed gallic acid to have the highest scavenging activity.
Finally, key enzymes encountered during digestion were encapsulated in the microemulsions and tested for their activity in presence and absence of antioxidants.
The developed system could be potentially used as effective carrier of antioxidants in food industry.
[1] A. Kalaitzaki, M. Emo, M. J. Stébé, A. Xenakis, and V. Papadimitriou, Food Res. Int. 54 (2013) 1448–1454.
[2] E.D. Tzika, V. Papadimitriou, T.G. Sotiroudis, A. Xenakis, Food Biophy. 3 (2007) 48–53.
mhatzidaki@eie.gr
