Hi there, intrepid PR person who wants to get in on this new "blog marketing" and "viral marketing" thing. I have some free advice for you, especially if you are trying to sell some kind of packaged, manufactured thing that only vaguely resembles real food.
Don't try to get food bloggers to try your stuff. Or let's put it this way: the owners of any food blog with a following, a reasonable backlog of articles, and enough traffic and Alexa ranking etc. to matter for you, is likely to be a Food Snob. That's the kind that your clients dread: they use real food, worry about seasonality (tomatoes in February make them gag), and, worst of all, actually cook. Or if they don't cook they eat out at places that serve real food.