What does blanching vegetables before freezing destroy to improve preservation?

Blanching vegetables before freezing is a critical step in the preservation process, primarily because it inactivates enzymes. These enzymes, if not deactivated, can lead to deterioration in color, flavor, and texture of the vegetables during storage. By briefly immersing vegetables in boiling water and then rapidly cooling them in ice water, the blanching process effectively halts enzyme activity. This ensures that the vegetables maintain their quality during freezing and extends their shelf life. While blanching can result in some loss of vitamins, the primary goal is to manage enzymatic action to preserve the overall integrity of the food.