Arming Nature's Grenade

摘要

"Let's suck away!" Physicist Paul quinn an- nounces, flipping the switch on his stove-top vacuum cooker. There's a long, low gurgling noise as a gauge registers the pressure drop inside, and the sound of muted machine-gun fire rattles the pot. Almost immediately, Quinn's lah at Kutztown University in Pennsylvania is permeated with 2-acetyl-1-pyrroline, the aroma given off by popcorn as it cooks. Eight minutes later, he removes the lid to reveal a pot brimming with fresh Orville Reden-bacher's. Though it's not apparent until the contents are poured into a graduated beaker, this popcorn has almost twice the volume of regular stove-top popcorn. The popcorn industry measures its product in three ways: the volume of the flake relative to its unpopped mass, the per- centage of popped kernels, and the amount of popcorn that can be harvested per acre. In the past half century, thanks to rigorous breeding, all three of those numbers have increased dramatically. Indeed, popcorn ranks among the greatest agronomic successes of the 20th century. Today the best popcorn pops twice as big as the popcorn of 50 years ago and leaves as little as one-fourth as many unpopped kernels, called old maids. And because popcorn is one of the only products bought by weight and sold by volume, bigger flakes translate into bigger profits.