1920s. Quick-freezing processes for foods were first commercialized by Clarence
Birdseye, whose name has become practically synonymous with frozen foods. Birdseye
found that by blanching vegetables (cooking them briefly in boiling water) just before
freezing, the process could deactivate certain enzymes that cause off-colors and offflavors,
thereby enhancing the quality of the thawed vegetables. The first commercial use
of “puffing” to produce such cereals as Cheerios and puffed rice also began.