What impact does freezing have on enzyme activity in food?

Freezing slows down enzyme activity in food primarily due to the low temperatures involved. Enzymes are proteins that facilitate biochemical reactions, and their activity is heavily influenced by temperature. At freezing temperatures, molecular movement decreases significantly, which leads to a reduction in the rate of these chemical reactions, including those facilitated by enzymes.

This reduction does not completely halt enzymatic activity, but it dramatically slows it down, which can help preserve the quality of the food by limiting the degradation of nutrients and the development of undesirable flavors. It's important to note that while freezing extends the shelf life of foods by slowing enzymatic and microbial activity, some enzymes can gradually re-activate when the food is thawed, which is why blanched vegetables are often recommended before freezing to further inhibit enzyme action. Understanding this mechanism is crucial for food preservation strategies.