This Is Why Your Defrosted Salmon Has Yellow on It

If you’ve noticed yellow or yellowish-brown discoloration on your defrosted salmon—especially along the edges or in fatty areas—it’s most likely due to oxidation of the fish’s natural fats, not spoilage. Here’s what’s happening and whether it’s safe to eat.
🟡 The Cause: Fat Oxidation (Not Spoilage)
Salmon is rich in healthy omega-3 fatty acids, which are prone to oxidation when exposed to air, light, or temperature fluctuations during freezing and thawing. This chemical reaction causes the fat to turn yellow, amber, or even slightly brown—similar to how an apple turns brown when cut.