Liposomes as vehicles for vitamins E and C: An alternative to fortify orange juice and offer vitamin C protection after heat treatment

MARINA MARSANASCO; ANDRES MÁRQUEZ; JORGE WAGNER; SILVIA DEL VALLE ALONSO; NADIA CHIARAMONI

FOOD RESEARCH INTERNATIONAL

ELSEVIER SCIENCE BV

Lugar: Toronto; Año: 2011 p. 1 - 34

0963-9969

Soy  phosphatidylcholine-based  liposomes were  studied  as  vitamin  transporters  to  be incorporated in orange juice, which is later subjected to pasteurization. These systems allowed  the  incorporation of vitamin E and C. Stearic acid and calcium stearate were incorporated  into  liposomes as an alternative  to  lipid bilayer stabilizers.   Calcium  ions and  essential  fatty  acids  are  contained  in  calcium  stearate  and  soy phosphatidylcholine,  respectively,  conferring  extra  nutritional  value.  Liposomes prepared by the dehydration-rehydration method were tested in a food model system to avoid  interference  caused  by  orange  juice  components.  The  oxidative  stability  was analyzed by the thiobarbituric acid method before and after the pasteurization process. Size was analyzed by  light scattering also before and after pasteurization, and shape was  analyzed  by  transmission  electron  microscopy.  Percentage  encapsulation efficiency  (EE%)  of  vitamins  C  and  E were  determined  by  a  centrifugation  process. Also, EE% of vitamin C was measured against dialysis for 72 hours. Liposomes had a protective effect on antioxidant activity of vitamins before and after pasteurization;  even  considering  that  vitamin  C  is  thermolabile.  Besides,  EE%  by centrifugation  showed  a  high  encapsulation  of  vitamin  E  and  C.  And  the  results  of dialysis  of  vitamin  C,  demonstrated  that  it  was  retained  by  all  the  systems. Formulations included stearic acid were the most efficient encapsulating with a 38%. The  results  showed  a  relationship between oxidative  stability  and  aggregation, along with  changes  in  size  and  morphology:  peroxidation  increases  with  aggregation. Addition of stearic acid  favors oxidative stability and EE% due  to a bilayer stabilizing effect.  It is important to note that the combination of liposomal formulations and vitamins with orange  juice  did  not  change  its  organoleptic  characteristics,  and  showed microbiological stability after pasteurization and storage at 4°C for 37 days.