Study of oxidative stability in time and temperature of liposomal membranes as carriers for vitamins E and C

MARSANASCO, M.; PRIETO, M.J.; ALONSO, S. DEL V.; CHIARAMONI, N.S.

Buzios

Congreso; VII Iberoamerican Congress of Biophysics 2009; 2009

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:Arial; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US; mso-fareast-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The objective of this work was to study the oxidative stability as a function of time of storage and temperature in liposomal formulations encapsulating vitamins E and C, providing a protective effect and incorporating these vitamins into aqueous foods to fortify them. Liposomes were developed with soybean phosphatidylcholine (SPC), and stabilizers for membranes like stearic acid (SA) and calcium stearate (CaS).   Methodology: Liposomes with vitamins were added in distilled water (pH >5) or acetic acid 3% w /v (pH < 5), aqueous food simulants. They were pasteurized at 65 °C for 30 minutes and the oxidative stability was evaluated with Thiobarbituric method. These systems were stored at room temperature for three months, and the oxidative stability was analyzed every fortnight. Another batch was stored at 4 °C for 30 days and the oxidative stability was evaluated every week.   Results: In pasteurized liposomes, stored at room temperature, SPC and SPC:SA showed higher oxidative stability in food simulant at pH less than 5, and in SPC and SPC:ECa in food simulant at pH greater than 5. In the case of formulations pasteurized and stored at 4 °C, they all showed higher oxidative stability.   Conclusions: Data showed a tendency of peroxidation in liposomes: as higher oxidative stability of liposomes, higher is the protection of vitamins and antioxidant properties. The low temperature slows the oxidative reaction, favoring the liposomal lifetime and protection of vitamins.