Both pieces + both hcs together
It doesn't look like it, but to Alucard the blood has different meaning depending on the person. While virgin blood to him is the equivalent of favorite sweet or candy bar and his current master's blood being the same as a rare but fine delicacy (like lobster is to us) due to being once in a blue moon he's given just a drop.
Now, to him, his beloved's blood is the equivalent to a homemade meal, cause it's something he expects and looks forward to after a mission, it gives him a feeling of home and comfort and doesn't food taste just better when it's from someone that you care for? To him it'd be like the best thing in the word since it comes from his beloved, the one he loves and cherishes.
Here's another personal headcanon I have for Alucard (and Seras too, plus to artificial/pseudo vampires but to some degree), but involving vamps and their way of finding their mates.
Everyone's blood has a distinct smell and taste. Vampires can find their mate by the taste of their love's blood better than the smell, cause although their beloved's smell will be tantalizing, it's easy to get it mixed with the smell of virgin blood as both scents can lure a vampire in. The only differences is that a beloved's blood will smell just as ambrosial whether they are a virgin or not and it may have a slight kick of something else as opposed to it's counterpart only smelling sweet and untainted. Relying on taste is most efficient since the taste different very widely between a mate and a virgin and as mentioned before, their love's scent has a slight kick if something, taste wise the kick's stronger and it'll taste just as exquisite even if again, their fated one is a virgin or not.