Wow, thanks for the all the replies.
Here's what I got after searching for deaerated fuel:-
TO MEMO the previous answer is right but I guess that your are looking for a more operational info regarding GRAVITY FUEL FEEDING when engine fuel pumps are inop. (FCOM 3.02.28 p10).
If flight time above FL 300 is greater than 30 min, it is time enough for all the air bubbles to be gone cause of the decreased pressure in the fuel tank (like a coke bottle when opened), so the fuel can be considered as deaerated (with no air diluted) and engines can be feeded by suction.
Thank you very much