USB storage write cache

[kuumaur]

Hi there,
i have a question regarding the write cache to usb pen drives or usb storage in general.
From time to time, it happens that the files that i copied to the pen drive are not really written to it.
I suppose it is due to the write cache.
Yes, there is a small hint, when i unmount the pen drive, but it happens that i am not aware of this.
Is it possible to disbale the write cache for usb storage devices?
I have had a look into the "gnome disk tool" and i found some mount options:
nosuid,nodev,nofail,noauto,x-gvfs-show
/mnt/usb-SanDisk_Cruzer_Blade_4C532000061205111511-0:0-part1

Is it possible to add the option "flush" and/or "sync" to the mount options?
Where are the default values for the mount options?

Thanks in advance
kuumaur