SIST EN ISO 15914:2005 PDF

Overview

EN ISO 15914:2005 (ISO 15914:2004) specifies an enzymatic laboratory method for the determination of total starch content in animal feeding stuffs and raw materials. Adopted by CEN, the method is also applicable to assessing the purity of starch. The procedure quantifies starch after solubilization and enzymatic conversion to glucose, followed by glucose measurement using the hexokinase spectrophotometric method (measurement at 340 nm).

Key facts:

• Analytical range: 40 g/kg to 1 000 g/kg starch
• Standard procedure applicable: 200 g/kg to 1 000 g/kg
• Alternate dilution procedure provided for 40 g/kg to 200 g/kg
• Important requirement: sample matrix must not contain components that absorb at 340 nm

Key topics and technical requirements

• Principle: Remove soluble sugars with 40% ethanol, solubilize starch in aqueous DMSO (90% v/v) at 100 °C and partially hydrolyse with concentrated HCl at 60 °C. Convert solubilized starch to glucose using amyloglucosidase; quantify glucose by the hexokinase enzymatic assay with spectrometric detection at 340 nm.
• Reagents: 40% ethanol, DMSO (90%), HCl (12 mol/L), amyloglucosidase solution (activity-specified), standard glucose solutions (different concentrations for two analytical ranges), Carrez clarifying reagents, acetate buffers.
• Apparatus: calibrated analytical balance, centrifuge, thermostatted water baths (100 °C and 60 °C), pH metre, pipettes, spectrophotometer capable of measuring at 340 nm, and appropriate centrifuge/ reaction tubes.
• Sample preparation: Follow ISO 6498 for test sample preparation; extraction removes soluble sugars prior to starch solubilization.
• Precision and reporting: The standard includes calculation, expression of results, precision data and reporting requirements for reliable inter-laboratory comparability.

Practical applications and users

EN ISO 15914:2005 is designed for laboratories and organizations involved in:

• Feed quality control and formulation (feed manufacturers, nutritionists)
• Raw material suppliers and starch producers (purity checks)
• Contract analytical laboratories and university research labs analyzing feed composition
• Regulatory and compliance testing for animal feeding stuffs

Benefits:

• Provides a validated, enzyme-based approach that targets total starch (including high-molecular-weight breakdown products)
• Enables consistent, comparable results across laboratories when following specified reagents, enzyme activities and analytical ranges

Related standards

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

Keywords: EN ISO 15914:2005, ISO 15914:2004, animal feeding stuffs, enzymatic determination, total starch content, starch analysis, amyloglucosidase, hexokinase method, 340 nm, DMSO, ethanol extraction.