Freezer Burn Improperly sealed packaging allows air to reach the sprouts, causing dehydration and discoloration. This affects the texture and color of the interior.
Overripe Before Freezing Brussels sprouts that were overripe or not fresh when frozen may already have started browning, and the freezing process preserved this condition.
Oxidation Exposure to oxygen before freezing or during thawing can cause browning, particularly if the sprouts were cut or damaged.
Blanching Issues If the sprouts weren’t properly blanched before freezing, enzymes may remain active, leading to discoloration even at freezing temperatures.
Improper Storage Temperature Fluctuating freezer temperatures can compromise quality, leading to internal browning over time.
Natural Aging Frozen Brussels sprouts, especially if stored for a long time, can naturally discolor as nutrients degrade over time.
Pest or Disease Damage Brussels sprouts with undetected pest damage or disease prior to freezing might have internal browning that only becomes apparent when thawed.