Several years ago, an apocryphal story was making the rounds. The president of one local supermarket chain called the cosuffering president of a rival chain to tell him the good news and the bad news. The good news was that Marian Burros had left the food section of the Star. The bad news was that she had gone to the Post.

Burros, food editor of The Washington Post, NBC-TV consumer commentator and super successful author of several cookbooks, is one tough-minded reporter who is a master exposer of the ersatz and debunker of the superhype behind and in the food we feed ourselves and our families. Pure & Simple will give no comfort to food manufacturers or purveyors, but for the rest of us, it's very good news.

Burros, who continues to promote label-reading with terrier-like tenacity, discusses the "Unrecognizable, unpronounceable ingredients" that, for example, "produce fake whipped cream" at rip-off prices. And despite such benign words as "enrichment" and "fortification," she says, "no amount of fortifying with a few nutrients is going to turn junk food into good food."

She has no use for packaged, over-processed "convenience" foods because most of them are neither good nor good for you. And while they're supposed to make life easier, she went to some pains to demonstrate on a television program that one product took longer to prepare and didn't taste as good as her scratch counterpart. She isn't against convenience - she miraculously figured out how we all can make up batches of convenience fodds at a fraction of the cost of the commercial varieties (and without additives). I am full of admiration for her few dozen recipes for mixes for, among others, instant cocoa, vegetable sauces, salad dressings, the sthake-it-and-bake-its and helps for hamburgers along with pancakes, biscuits and cookies. These alone are worth their weight and more in un-nitired bacon and undyed cheddar cheese.

The rest of the recipes are healthy, easy, and wonderfully varied - Chinese, Middle Eastern, Mexican - and in tune with the times: heavy on vegetables and fruits. And no additives. As I said, very good news, (Morrow, $9.95)