AOAC OMB Final Action Recommendation (December 2019)-2016.14

FOS-03 FOR WORKING GROUP/ERP USE ONLY DO NOT DISTRIBUTE

Determination of Fructans in Infant Formula and Adult Nutritionals High-Performance Anion-Exchange Chromatography with Pulsed Amperometric Detection

Sean Austin and Denis Cuany

Nestlé Research Centre, Vers-Chez-Les-Blanc, PO Box 44, CH-1000 Lausanne 26, Switzerland

Notes :

1. The method described and data presented are already published in Cuany,D., et.al.

(2010) J. AOAC Int . 93(1): 202-212

2. We are currently working on an improvement of this method but it is not yet ready

for submission. Main changes will be:-

a. Different column (avoids need for post-column addition of NaOH).

b. Addition of an internal standard.

c. Removal of the drying step after SPE .

d. Determination of 4 analytes (glucose, fructose, sorbitol and mannitol) to

avoid the need for correction factors.

e. Use of multi-point calibration.

A. Applicability Statement

This method is suitable for the determination of fructans in infant formula (has not yet been

validated on adult nutritional products)

B. Principle

Fructans are extracted from the sample with hot water. An aliquot of the extract is treated

with a sucrase to hydrolyse sucrose into glucose and fructose. Concurrently, starch and

maltooligosaccharides are hydrolysed to glucose by combined action of highly purified

amylase, pullulanase and maltase. Reducing sugars are then reduced to the corresponding

sugar alcohols by treatment with alkaline borohydride and the mixture cleaned up by SPE on

a graphitized carbon column, thus removing all monosaccharides and borate salts. Fructans

are recovered from the column by elution with acetonitrile/trifluoroacetic acid and dried.

The dried fructans are redissolved and treated with a purified fructanase (endo and exo-