Matthew 26:29 But I say unto you, I will not drink henceforth of this fruit of the vine, until that day when I drink it new with you in my Father's kingdom.
Not only did He partake but it was wine not physical blood.
of course it wasn't physical blood, nor is it in a Mass...it is wine, fruit of the vine which has been transubstantiated into the Blood of Christ....still under the appearance of wine.