Adulteration — Chemicals & Water
Phosphates, sulphites, brines, and undisclosed additives bulking weight and masking age.
Adulteration adds substances to seafood that weren't disclosed on the label. This includes water-binding phosphates that increase pack weight by 20–30%, sulphites that prevent black-spot in prawns but trigger allergic reactions in sensitive consumers, and a range of undisclosed brines and preservatives used to extend shelf life or improve appearance.
The mechanism is simple: a product is soaked, injected, or tumbled with a solution before freezing or packing. The water or additive is absorbed into the flesh — adding weight at no cost — and is invisible once the product is sealed. The consumer pays premium price per kilogram for water or phosphate solution they cannot detect at the counter.
Why it persists
Labelling laws often allow "moisture added" or carrier statements without quantification. "Contains added water" is technically compliant even if 30% of the pack weight is water. Consumer testing of specific additives is functionally impossible at the point of sale — it requires laboratory analysis.
Red flags
- Excessive moisture released during cooking — product "steams" rather than sears
- Unusually translucent, bright-white, or wet-looking scallop or prawn flesh
- Pack weight inconsistent with apparent product volume when thawed
- Unlisted additives or vague "moisture added" without quantification
- Allergen warnings absent for sulphite-treated product
Counter-measures
- Mandatory quantitative additive labelling — exact percentage by weight
- Cook-out weight disclosure (weight after cooking, not just raw weight)
- Allergen-specific sulphite warnings on all treated product
- Additive testing at border inspection and retail audit
Who needs to act — and how
Adulteration can only be detected through testing — making procurement-level controls critical.
What you can do
- Look for "moisture added" disclosures and quantified percentage
- Prefer product with cook-out weight declared on pack
- If you have a sulphite allergy, scrutinise all prawn and shellfish labels
What you can do
- Require supplier disclosure of all additives and retention percentages
- Request additive testing certificates for high-volume lines
- Mandate cook-out weight testing as part of supplier qualification
What you can do
- Declare all additives on commercial invoices and product specifications
- Implement incoming product testing for phosphate retention and moisture content
- Refuse supply from processors who cannot quantify additive use
What you can do
- Require quantitative declaration of all added moisture and phosphates on label
- Mandate allergen warnings for sulphite-treated product at all retail levels
- Include additive testing in seafood surveillance programs