I want to study the physical and oxidative stability of O/W emulsion stabilized by protein-polyphenol conjugates under accelerated storage conditions.
I want to avoid the temperature factor because the emulsions are not physically stable at 50°C, after two weeks an oil layer is forming on top of the emulsion.
I was then thinking about using FeSO4 or the complex FeSO4/EDTA to accelerate the oxidation however, I saw that phenolic antioxidants can act as prooxidants under certain conditions (for example, high concentration of transition metal ions) (Eghbaliferiz, S, 2016).
I was wondering if by using FeSO4 and the conjugates that contain polyphenol, the lipid oxidation would increase in comparison to the control (protein alone). Does anyone have any experience with this situation?
Thank you very much for your help!
@ Hello Aurélie,
Yes, it is possible the Fe II can be considered as an oxidation catalyst with dissolved O2 in the water phase, production of oxygenated free radicals by Fenton/Haber-Weiss reactions will be accelerated finally leading to lipoperoxydation.
But the reaction will only occur in the water phase, there will be other possible interaction Fe chelation by polyphenols, direct Fe polyphenol oxidations, formation of colored phenol-Fe complex... And generally when polyphenol-protein complex are oxidised, they lead to insoluble complex ie polyphenol-protein haze formation during beverages storage…
So model will be probably difficult to interpret, perhaps visualisation of protein-polyphenol complex at lipid micelle interphase will be also helpful to define the domain where protein-polyphenol oxidation will not have too important consequences on the OW emulsion destabilisation…
And try to be in acidic conditions in the water phase, otherwise polyphenols, especially procyanidins will be quicly "autoxidised" as usually we consider that they are stable until pH 4.5-5 not more.
Interesting topic and quite challenging in experimental modelling with lot of controls and blanks to get enough reproductibility...;-)
BR Philippe
- Badges
- Science topic
- Similar topics
- Phytochemistry
- Extracts