Seafood Sulfite Level Testing Strips

SKU: 33817-S

$27.95USD or lower Each

Save More When You Buy More!
Quantity1+2+ 3+ 10+ 
Price for each$27.95USD$26.65USD$25.65USD$25.37USD
Your savings - 4.65%8.23%9.23%
Qty:
[5]   2 Reviews    | Write a Review

Check shrimp and seafood for sulfites using Indigo® sulfite test strips. Detect free sulfite on surfaces, prevent browning, and verify proper labelling.

Sulfites are widely used in the seafood industry, especially on shrimp, to slow bacterial growth and prevent enzymatic browning after peeling. Because sulfites can remain on the surface of seafood, chefs, food processors, inspectors, and consumers sometimes need to verify whether sulfite is present. Indigo® sulfite test strips provide a fast way to detect free sulfite directly on seafood surfaces at levels as low as ~10 ppm.

Details Specs Docs Reviews
Details

How to Test Seafood for Sulfites

Testing shrimp or other seafood is simple:

  1. Moisten the test strip pad with clean water (distilled or deionized preferred).
  2. Press the wetted pad firmly against the surface of the seafood for 1–2 seconds.
  3. Wait for the color to develop and compare it to the chart provided.

A visible color change indicates the presence of free sulfite above approximately 10 ppm.

Seafood Sulfite Testing for Food Chemistry + Culinary Science

Concept Description Activity Learning Link
Enzymatic Browning in Seafood Sulfites prevent melanosis ("black spot") in shrimp by inhibiting polyphenol oxidase. Compare sulfited vs. unsulfited shrimp over several hours. Food chemistry, enzyme inhibition, oxidation reactions.
Free vs. Bound Sulfites Only unbound sulfite reacts with the test strip; bound sulfites do not trigger color change. Test fresh vs. stored shrimp to observe reduction in free sulfite. Allergen risk assessment, preservative mechanisms.
Preservatives in Seafood Processing Sodium metabisulfite and bisulfite salts are commonly used to extend shelf life. Identify labelled and unlabeled samples using the strips. Regulatory compliance, food safety labeling.
Surface Testing Techniques Testing detects only surface-applied sulfites, where reactions are most active. Press wetted strips on various seafood types (shrimp, scallops, squid). Analytical method comparison, qualitative detection.

The presence of sulfites may be listed on food labels as: sulfur dioxide, potassium bisulfite, potassium metabisulfite, sodium bisulfite, sodium metabisulfite, or sodium sulfite.

If free sulfite is present above 10ppm, the pad will change color. Read more in our blog on what the 10ppm level really means. For those interested in the chemistry of how these strips work, please refer to this pdf which explains the theory of how free sulfite is detected.

Related information or images
Sulfite Test Strips 100/Vial

Sulfite Test Strips 100/Vial

Cut Potato Sulfite Level Testing Strips

Potatoes

Testing Sulfite Levels in Apple Cider

Cider Preservative

Dried Fruit Sulfite Level Testing Strips

Dried Fruit

Wool Processing Sulfite Test Strips

Wool

Red Wine Sulfite Level Testing Strips

Red Wine

White Wine Sulfite Level Testing Strips

White Wine

Specifications

This Indigo® test strip indicates the presence of sulfite ion in increments of 10, 50, 100, 250, and 500ppm after 15 seconds.

  • The number of strips (100) vial is approximate.
  • Vial has a built in desiccant and if kept tightly closed, strips can be effective up to 5 years.
  • For more information, see: Test Strip Expiration Dates; Good Today, Dead Tomorrow?
  • Strips test for: sulfite, bisulfite and metabisulfite
Documentation

Test Strip Documentation
Stability Statement Certificate of Analysis SDS
Indigo Sulfite Test Strips 0-500ppm Stability Statement Indigo Sulfite Test Strips 0-500ppm Certificate of Analysis Indigo Sulfite Test Strips 0-500ppm SDS
Reviews (2)
2023-10-27

Test strips worked as described, including the red wine citric acid method. I first did some comparisons using sulfites in water. Dipping the strips and the citric acid method gave the same result, albeit a little lower than expected. Solution was mixed to 100 ppm and both strips showed about 75. Used a similar technique on red wine, although dipping does not work. Wine with no sulfites showed zero. Added and got similar readings to the water results. Thanks for the great product and the citric acid trick.

2021-01-22

Great place for a hard to find product. Excellent price! Quick shipping.

— Quality Control
— Indigo:

Thanks for letting us know. This might interest you since you are in quality control: Can 10ppm of Sulfite & Quat Really Mean Zero?

Review This Product Now!