Overview
ISO 7102:2024 - Infant formula: Determination of β‑galactooligosaccharides (GOS) - specifies a validated analytical method to quantify β‑galactooligosaccharides (GOS) in infant formula (powder and ready‑to‑feed liquids). The procedure uses ultra high performance liquid chromatography (UHPLC) with fluorescence detection (FLD) after pre‑column derivatization with 2‑aminobenzamide (2AB). The method covers product concentrations from 0.2 g/100 g to 3.0 g/100 g (ready for consumption) and has been validated in multi‑laboratory and single‑laboratory studies.
Key topics and technical requirements
- Sample scope: Powdered/concentrated infant formula (reconstituted) and ready‑to‑feed (RTF) liquids.
- Analytical principle: Extraction of oligosaccharides, enzymatic hydrolysis (amyloglucosidase to remove maltooligosaccharides; β‑galactosidase for total GOS determination), internal standard addition (laminaritriose), fluorescent labelling with 2AB, UHPLC‑HILIC separation and FLD detection.
- Calibration and quantification:
- External calibration with maltotriose (2AB response assumed equivalent molar response).
- Conversion from molar to mass concentrations requires molecular weight determination - via LC‑MS (Annex C) or dextran ladder (Annex B).
- Chromatography: HILIC column with gradient of aqueous ammonium formate in acetonitrile (as mobile phase).
- Enzymes and reagents: amyloglucosidase and β‑galactosidase (Aspergillus niger), 2AB, 2‑picoline borane, laminaritriose internal standard, maltotriose standard.
- Validation data: Multi‑lab validation at ~0.236–0.688 g/100 g (reconstituted) and 0.316 & 0.858 g/100 g (RTF); spike‑recovery studies up to 3 g/100 g in various formula matrices.
Applications and users
- Quality control and regulatory testing: Infant formula manufacturers and contract testing laboratories can use ISO 7102:2024 for routine GOS content verification and label compliance.
- Product development and R&D: Nutrition scientists assessing prebiotic content or formulating GOS‑enriched products.
- Regulatory authorities and food safety labs: For enforcement, compositional analysis and harmonized reporting.
- Clinical nutrition and third‑party certification bodies: Verifying declared oligosaccharide levels in specialized formulas.
Keywords for discoverability: ISO 7102:2024, infant formula, β‑galactooligosaccharides, GOS analysis, UHPLC‑FLD, 2‑aminobenzamide derivatization, HILIC, maltotriose calibration, dextran ladder, method validation.
Related standards
- Equivalent to AOAC Official Method 2021.01 (noted in the ISO/IDF foreword).
- Developed under ISO/TC 34 (Food products), SC 5 (Milk and milk products) in collaboration with IDF and AOAC.