23 / 41
FOR EXPERT REVIEW PANEL USE ONLY
NOT FOR DISTRIBUTION
1
Expert Review Panel for Infant Formula and Adult Nutrition
Evaluation of Method GOS-01
Title:
Single Lab Validation of a Method for the Determination of β-Galactooligosaccharides in Infant
Formula & Adult Nutritionals
Author:
Sean Austin (NRC, Lausanne), Denis Cuany (NRC, Lausanne), Catherine Murset‐Mounoud (NRC,
Lausanne)
Summary of Method:
Samples of infant and/or adult nutrition are reconstituted in water and further diluted to an appropriate
concentration of GOS. An aliquot of the sample solution is taken and an internal standard is added. This
sample is then split into two aliquots of which one aliquot is treated with a β‐galactosidase; the other is
not. Both aliquots are labelled with a fluorescent tag, 2‐aminobenzamide (2AB). After labelling, both
aliquots are treated with amylo-glucosidase to remove maltodextrins, followed by analysis with hydrophilic
interaction liquid chromatography (HILIC) with fluorescence detection (FLD). Each oligosaccharide has an
equivalent molar response in the detector. It is therefore necessary to know the molecular weight of each
signal in the chromatogram to convert the molar quantities that are analysed to mass quantities. This can
be done by coupling a mass spectrometer to the HPLC (but once a GOS ingredient profile has been
characterized by HILIC‐FLD‐MS, future samples can be analysed without the MS).
Method Scope/Applicability:
The method is applicable to all types of samples supplied in the SPIFAN testkit, being infant formula and
adult/pediatric nutritional formula.
General comments about the method:
-
The method is suitable to detect GOS in infant formula and adult nutrition
-
The method contains many steps (of longer duration) prior to analysis
Method Clarity:
The method is clearly written, though one should work precisely and accurately to get appropriate results.
Method Safety Concerns:
-
Some hazardous/toxic materials are used in the protocol (e.g. Sodium cyanoborohydride)
Pros/Strengths:
-
GOS content can be determined in lactose containing matrices.
-
Less complex and labor intensive method than GOS-02.
-
Polydextrose containing products do not interfere with the results.
Cons/Weaknesses
-
Expensive equipment (MS) needed to be able to determine GOS content; method is set-up as a
research method.