What is the primary purpose of blanching vegetables before freezing?

• A. To inactivate enzymes that would deteriorate food during storage
• B. To sterilize vegetables completely
• C. To remove moisture from vegetables
• D. To caramelize sugars

Answer: (A)

The main idea here is that a brief heat treatment before freezing stops the chemical changes that enzymes cause in vegetables, helping them keep color, flavor, and texture during storage. Blanching in hot water or steam denatures enzymes like polyphenol oxidase and others that would otherwise cause browning, softening, or off-flavors once the produce is frozen and kept for months. By inactivating these enzymes, the vegetables stay closer to their fresh quality when you eventually thaw and eat them.

It isn’t intended to sterilize everything on the surface, so it won’t kill all microbes or spores. It also isn’t about removing moisture; some water loss can occur, but that isn’t the primary goal. And caramelizing sugars requires much higher, dry heat, so blanching won’t caramelize sugars in vegetables. Quick cooling after blanching is used to stop cooking and preserve texture and color.