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.
Try pushing samples of some odd food substitute or anything that Quick ‘n Easy to these people: you’re likely to be ignored at best, and publicly scorned on their blogs at worst.
Remember what you used to do in the good old pre-interweb days - send samples out to ‘regular housewives’? Housewife is a rather non-PC term these days but that’s the way you should be going really: finding busy people who have to cook but don’t obsess about food. Busy moms and dads, students maybe? But not a food blogger.
Hint: tell your unpaid intern to take the time to actually look around a food blog. If there’s any whiff of words like “farmer’s market”, “CSA”, “grass fed” or “Le Creuset”, tell them to tick it off the list of bloggers to spam. You’ll be saving her, and you, a lot of time.
Or, to keep it simple: you really should only try approaching the food blogger segment if you, yourself, would actually eat whatever you’re trying to push.
Additional required reading: The Do’s and Don’ts of Marketing to Bloggers  by Elise Bauer.