Tool of the Month – FeedCheck Soy: Assessing antinutritional factors in soybean meal

Name: FeedCheck Soy

Cost: Contact your local Canadian Biosystems (CBS Inc.) representative or distributor for price information

Available at Canadian Biosystems websites (link)

Intended use

A FeedCheck Soy device is used for on-site quality assessment of soybean meal, specifically by analyzing the urease enzyme activity within the soybean meal. Ensuring the quality of soybean meal is important for its efficacy in animal nutrition. One crucial aspect of this quality control involves evaluating the presence of antinutrients, particularly the trypsin inhibitor, which can hinder protein digestion. Properly heating soybeans is crucial to deactivate this inhibitor, delicately managing the balance between underprocessing, which leaves behind residual antitrypsin, and overprocessing, which triggers unwanted Maillard reactions. These reactions can reduce the availability of amino acids by interacting with sugars.

A key player in this quality assessment is the urease enzyme, naturally present in soybean meal. Interestingly, urease and antitrypsin exhibit similar sensitivities to heat. Consequently, testing for urease activity serves as a reliable indicator of the degree of underprocessing in soybean meal.

How does it work?

A sample of soybean meal is introduced to a urea solution. As the urease enzyme catalyzes the hydrolysis of urea, ammonia is released, causing a rise in pH. This change in pH can be quantified using an indicator dye such as phenol red. The presence of more red dots on the surface of the tested soybean meal indicates a higher level of urease activity, suggesting greater underprocessing and, consequently, elevated levels of antitrypsin. The following image shows the difference in the red dot formation on three soybean meal samples (properly cooked, undercooked, and overcooked) following the reaction with the urea solution.

Samples of urease test images (From left to right: properly cooked, undercooked and overcooked). Picture source: İlyas Özer, 2021 (link to the article

This method of assessment is not only valuable for ensuring the nutritional quality of soybean meal but also for safeguarding the efficiency of protein digestion in the gastrointestinal tract, as antitrypsin interference can compromise this vital process.

Using the device

Upon receiving your FeedCheck Soy kit, please ensure the following items are included: a 16-fluid-ounce bottle of the reaction reagent, five petri dishes, five transfer pipettes, one measuring spoon, and a user guide.

Upon receipt, promptly store the reaction reagent in the refrigerator. If any of these items are missing, please contact your CBS representative for a replacement kit or the missing item.

To utilize the FeedCheck Soy with your soybean meal samples, follow these steps:

  1. Retrieve the reaction reagent from the fridge and pour a sufficient amount into the container based on the number of samples to be analyzed. Refer to the user guide for guidance on the amount needed.
  2. Allow the solution to reach the room temperature.
  3. Grind the soybean meal sample and weigh approximately 2 grams or one teaspoon of the sample into one of the petri dishes.
  4. Swirl the sample until it is free of clumps.
  5. Fill a transfer pipette with the room temperature reaction reagent and evenly add it to the sample, starting from the edges of the petri dish and working towards the center. Repeat this step twice or until the sample is uniformly covered with the reagent.
  6. Swirl the petri dish until the sample is saturated.
  7. Start the timer and let the sample stand for five minutes, if necessary, during that time add extra drops of the reaction reagent to ensure the sample does not dry out.
  8. Count the red dots and evaluate the sample using the FeedCheck Soy scale provided in the user guide. As mentioned, the more red dots on the surface of the tested soybean meal indicate a higher level of urease and antitrypsin activity in the feed sample.

Some precautions to keep in mind:

  • Do not use the transfer pipette to measure any other liquid.
  • Do not return the working solution to the storage bottle, as contamination may occur, reducing the stability of the reaction reagent.


Canadian Biosystems websites (link)

Özer, İ. (2021). Classification of Urease Activity in Full-Fat Soybean Production by Extrusion Using Machine Learning Algorithms. Balkan Journal of Electrical and Computer Engineering, 9(3), 290-296. (link)

About the author(s)

Research Associate at Poultry Innovation Partnership | + posts