ISO 15914:2004

Overview

ISO 15914:2004 - "Animal feeding stuffs - Enzymatic determination of total starch content" specifies a validated laboratory method for measuring total starch in animal feeds and raw feed materials. The standard describes an enzymatic procedure that converts solubilized starch to glucose and quantifies glucose enzymatically (hexokinase method), with measurement at 340 nm. The method covers an analytical range of 40 g/kg to 1 000 g/kg starch (standard procedure 200–1 000 g/kg; alternate dilution for 40–200 g/kg).

Key topics and technical requirements

• Principle: Remove soluble sugars with 40% ethanol, solubilize starch in 90% DMSO at 100 °C, partially hydrolyse with concentrated HCl at 60 °C, enzymatically convert starch to glucose using amyloglucosidase, and quantify glucose using the hexokinase UV method (measurement at 340 nm).
• Analytical range: 40–1 000 g/kg (standard workflow optimized for 200–1 000 g/kg; alternate dilution procedures provided for lower concentrations).
• Interference control: Sample matrices must not contain components that absorb at 340 nm (avoid false results from interfering extinction).
• Reagents & enzymes: Specifies DMSO 90% (v/v), 40% ethanol, Carrez clarifying reagents, amyloglucosidase solution (activity defined), and freshly prepared standard glucose solutions.
• Apparatus: UV spectrometer capable at 340 nm, centrifuges, calibrated pipettes, water baths (100 °C and 60 °C), pH meter, and suitable centrifuge tubes.
• Sample preparation: Follow ISO 6498 for feed sample prep and use water meeting ISO 3696. Tests are performed in duplicate with a sample blank in each series.
• Precision & reporting: Contains procedural details for calculation, precision, and required test report content.

Applications and who uses it

ISO 15914:2004 is used for:

• Routine quality control in feed manufacturing and formulation
• Contract testing laboratories analysing feed raw materials (cereals, by-products)
• Verification of starch purity in starch products
• Regulatory and compliance testing where standardized starch quantification is required
• Nutritional analysis for feed formulation and labelling

Primary users:

• Feed manufacturers and mill laboratories
• Agricultural testing and food/feed analytical labs
• Academia and research groups studying feed composition
• Regulatory agencies overseeing feed composition standards

Related standards

• ISO 6498:1998 - Preparation of test samples for animal feeding stuffs (referenced for sample prep)
• ISO 3696:1987 - Water for analytical laboratory use (reagent water quality)

Using ISO 15914:2004 ensures reproducible, enzyme-based starch analysis in animal feeding stuffs, supporting accurate feed formulation, quality control, and compliance with international testing practices.