Per the 7 essential meta questions, I don't think this has been answered for 'food and cooking' in particular.
This question attempts to get a list of relevant blogs and other notables from the online community that we should contact. This selects for people likely to be young and 'internet savvy.' While this would be an intuitive strategy for the Trilogy and several of the new betas rolling off Area 51, maybe 'Food and Cooking' needs something different to capture the experts we are looking for?
I think this would be a moot question if we agreed that only people who are 'internet savvy' will reliable contribute to our site. But if we are confident that anyone, with time, can learn the ropes on Stack Exchanges, and that we want even those experts that spend little time on the web, than how do we reach them?
It might be too early to develop methods for contacting these experts. But I think we can decide whether or not we want them on the site, and whether we should think about reaching them at all.