I've been attempting to make green smoothies lately as part of a health kick. The way I've been doing it is to use a normal smoothie recipe, but to add handfuls of spinach.
In general, the results haven't been bad, and certainly better than I expected, but I do find the spinach to add a bit of undesired astringency the smoothie.
Now I know that certain tastes can counteract the perceived effect of other tastes. For example, sweetness can counter sourness, or salt can counter bitterness.
I tried experimenting a bit with adding (separately) honey, lemon, and salt, but none of these seemed to make a difference in the astringent feeling the smoothie left in the mouth. What taste, if any, can counter astringency?