One day, from the recesses of her fridge, Melanie Warner unearthed a tub of "fresh guacamole" she'd forgotten about for nine months. It "didn't look particularly fresh," she writes, "but there was no mold and no bad smell." The culprits -- or saviors -- she figured, had to be the ascorbic acid, citric acid, xanthan gum, amigum and "text-instant" that followed avocados and salt on the ingredients label. "It didn't look like a processed food, but that's exactly what it was."
Warner threw out the guacamole and began to investigate. Her travels through a largely hidden landscape of laboratories, factories and trade shows inform "Pandora's Lunchbox: How Processed Food Took Over the American Meal" (Scribner, $26). Don't read it if you want to keep enjoying breakfast cereal or frozen chicken nuggets. The book will shake your beliefs that the thousands of chemicals routinely added to food have been declared safe by the FDA or that synthetic vitamins are the same as their naturally occurring counterparts. But if you're concerned about food safety and the perils of the agricultural-gastronomic complex, it is indispensable.