Final answer:
Vegetables must be blanched before freezing to inactivate enzymes that can degrade quality during storage. Blanching involves boiling or steaming followed by rapid cooling.
Step-by-step explanation:
Prior to freezing, vegetables must be blanched before freezing to stop the damaging actions of enzymes. Blanching is a process that involves scalding vegetables in boiling water or steam for a short time, then plunging them into ice water to halt the cooking process. The purpose of blanching is to destroy enzymes that can cause loss of flavor, color, and texture during freezer storage, as well as to clean the surface of the vegetable and reduce the number of spoilage microorganisms.