Comparing the assay substrates behind xylanase activity in U/g

Can two U/g values be used directly to compare prices?

Activity units depend on substrate, reaction conditions and unit definition. A xylanase result cannot be priced against the total activity of an enzyme blend.

Match substrate and unit definition first

Check method revision and substrate. Compare activity before and after processing by one method, then evaluate against the substrate composition of the actual diet. Record carrier and process history.

Can total activity of a multienzyme product replace a single-enzyme specification?

Request xylanase-specific activity and identify other enzymes. Validate their functions and stability separately. Cereal-based diets: List the main cereals and the arabinoxylan substrate background. Compare in the same basal formulation. Enzyme activity after pelleting: Test samples before and after conditioning with the same assay and check mixing uniformity at multiple points.

Checking Xylanase activity and Substrate and assay method

Xylanase activity (U/g as defined by the supplier method): Specify substrate, temperature, pH and the sugar-release endpoint. Compare only on the same activity-unit definition. Substrate and assay method (Method description): Specify substrate type, concentration, assay time and blank correction. Retain the method used for sample approval. Retention after processing (%): Measure activity before and after processing by the same method and correct for moisture. Record temperature, residence time and cooling conditions.

What to record

• Method revision
• Assay substrate
• Activity unit
• Pelleting conditions
• Residual activity

Technical references

• BASF Natugrain Wheat TS: xylanase and TXU measurement ↗

Products and processes