Your answer is n your question!

Because- 50% of water and 50 % of methanol get the antioxidants that are both "water soluble- phenolics, flavonoids, glycosides, proteins, carbohydrates, vitamins" and "methanol(lipid) soluble- say lipids, carotenoids, chlorophylls, steroids, sterols, etc." more effectively, than either one of them in isolation!  So, of course the chances to get both the worlds is easier than only MeOH/H2O.

However, if you isolate separately in H2O and MeOH 100% each, and then combine 1: 1 ratio, then it would be far more effective than 50%-MeOH-H2O! Experiment this as well!

Thanks,

Biswa

The mixture of MeOH-H2O or ETOH-H2O extracted much polyphenols compounds than each solvent individually. In your case you will have in your extract much macromolecules like tannins...These macromolecules can influency the activity of the radical dpph

I agree with Biswapriya Biswavas Misra. Both solvents works together for better antioxidant activity

For good extraction for flavonoids I would recommend 62.5% aqueous methanol for the above reasons mentioned in this thread.

Best regards

Aly

Thesis Chapter 2-TO INVESTIGATE THE ANTIOXIDANT PROPERTIES OF DIETA...

Most of the active compounds showing antioxidant activity are readily extracted with 50% MeOH -H2O solvent system rather than 100%  MeOH  or 100%H2O