ISO 22579:2020

Overview

ISO 22579:2020 specifies a validated laboratory method for the determination of inulin‑type fructans (including oligofructose and fructooligosaccharides) in infant formula and adult nutritionals (powder and liquid). The method uses enzymatic treatments followed by high‑performance anion exchange chromatography with pulsed amperometric detection (HPAEC‑PAD) to quantify fructans in the range 0.03 g/100 g to 5.0 g/100 g in products as prepared ready‑to‑consume. ISO 22579:2020 is published jointly by ISO and IDF and is equivalent to AOAC Official Method 2016.14.

Key topics and requirements

• Scope and validation: Multi‑laboratory validation using reconstituted standard reference material and various formula matrices; single‑lab spike recoveries up to 5 g/100 g.
• Sample preparation: Reconstitution/dilution rules for powders and ready‑to‑feed (RTF) products; optional Carrez clarification for difficult matrices.
• Enzymatic treatments:
  • Sucrase and α‑glucanase mix to hydrolyse sucrose and α‑glucans while preserving fructans.
  • Fructanase mixture (exo/endo‑inulinases, endo‑levanase) to hydrolyse retained fructans into glucose and fructose for detection.
• Clean‑up: Solid phase extraction (SPE) on graphitized carbon to separate fructans from salts and monosaccharides prior to hydrolysis.
• Chromatography and detection: HPAEC‑PAD conditions (columns A or B variants), system suitability testing, calibration with fructose and glucose standards.
• Calculation: Fructan content reported by summing measured glucose and 0.9 × measured fructose; blank corrections where applicable.
• Safety: Use of corrosive (sodium hydroxide, acetic acid) and potentially toxic reagents (sodium azide) - follow MSDS and waste protocols.
• Quality data: Sections on precision, repeatability and reproducibility, calibration, and test reporting.

Applications and users

ISO 22579 is intended for:

• Food testing laboratories performing routine or regulatory analysis of infant formula and adult nutritionals.
• Manufacturers of infant and adult nutrition products for product development, labeling, and QA/QC.
• Regulatory authorities and third‑party certifiers verifying fructan content for compliance and nutrition labeling.
• R&D and clinical nutrition researchers studying prebiotic content (fructans) in formula and medical nutrition products.

Practical benefits include standardized measurement of inulin‑type fructans for consistent labeling, formulation control, and safety/regulatory compliance.

Related standards

• Equivalent to AOAC Official Method 2016.14 (Fructans in Infant Formula and Adult Nutrition).
• Developed in collaboration with CEN/TC 302 and referenced alongside Codex definitions for infant and follow‑up formula.

Keywords: ISO 22579:2020, infant formula, adult nutritionals, fructans, inulin, oligofructose, fructooligosaccharides, HPAEC‑PAD, enzymatic treatment, SPE, method validation.