SIST EN ISO 8381:2009 PDF

Overview

EN ISO 8381:2008 (ISO 8381:2008 / IDF 123:2008) specifies the reference gravimetric method for determining the fat content of milk‑based infant foods. The method is based on the Röse‑Gottlieb extraction principle: an ammoniacal ethanolic solution of a test portion is extracted with diethyl ether and light petroleum, the solvents are removed, and the extracted fat is weighed. It applies to liquid, concentrated and dried milk‑based infant foods containing no more than 5% (dry matter) of added starch, dextrin, vegetables, fruit or meat. The standard is published by CEN/ISO/IDF and is intended as a reference analytical procedure.

Key Topics and Requirements

• Scope and limitations
  • Applicable to milk‑based infant foods (liquid, concentrated, dried) with ≤5% added matter (dry basis).
  • Not applicable to products that do not dissolve in ammonia (high starch/dextrin or hard lumps) or those with significant free fatty acids - such samples give falsely low results.
• Analytical principle
  • Röse‑Gottlieb gravimetric extraction: ammoniacal ethanol extraction followed by diethyl ether / light petroleum extraction and solvent removal.
• Reagents and safety
  • Key reagents include ammonia solution (~25% NH3), ethanol (≥94% vol), diethyl ether (peroxide‑free), and light petroleum (30–60 °C range).
  • Safety warning for flammable/volatile solvents (especially diethyl ether).
• Apparatus & sampling
  • Specifies laboratory glassware and extraction vessels (references include Mojonnier‑type flasks and volumetric equipment).
• Procedure and quality control
  • Detailed sample preparation for liquid, viscous and dried products, blank tests, fat‑collecting vessel preparation, calculation and expression of results.
  • Includes precision data: interlaboratory tests, repeatability and reproducibility requirements.

Applications - Who uses this standard

• Food control laboratories and regulatory agencies verifying declared fat content of infant formula and milk‑based baby foods.
• Manufacturers validating product composition and performing quality control for product release.
• Research laboratories comparing fat content across formulations.
• Certification bodies auditing compliance with compositional regulations.

Related standards

• ISO 8262‑1 / IDF 124‑1 (Weibull‑Berntrop method) - alternative for products not suitable for Röse‑Gottlieb.
• Normative references cited in EN ISO 8381:2008: ISO 835, ISO 1042, ISO 3889 (Mojonnier‑type flasks), ISO 4788.

Keywords: EN ISO 8381:2008, ISO 8381, milk‑based infant foods, fat content, gravimetric method, Röse‑Gottlieb, fat extraction, reference method, diethyl ether, Mojonnier.