6. AOACSPIFANMethods-2018Awards

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1578  H aselberger & J acobs : J ournal of AOAC I nternational V ol . 99, N o . 6, 2016

Table 2016.06B. Total fructan single-laboratory validation data: Recovery from overspiked SPIFAN samples 50% Overspike 100% Overspike

No. of replicates a

Spiking material b

Native fructan level, g/100 g c

Sample type

Avg. % rec.

RSD, % Avg. % rec.

RSD, %

Child formula powder

6 6 6 6 6 6

scFOS

0.277 0.233 0.283 0.277 0.036 0.500

97.2 108 101 102 97.4 92.9

6.28 4.38 8.53 4.78 11.1 4.91

100 105 98.7 96.0 97.6 94.2

3.74 15.0 4.82 5.75 7.91 12.6

Toddler formula powder, milk based Infant formula powder, milk based

Oligofructose Oligofructose

Child formula powder

scFOS

Infant formula powder FOS and GOS

Oligofructose

Adult nutritional RTF high fat

scFOS

a  Duplicates on each of 3 days. b  From SPIFAN kits. scFOS = Ingredion Nutraflora FOS powder. Oligofructose = Beneo Orafti P95 powder. c  Mean from previous precision determination, duplicates on each of 6 days.

internal standard (IS; glucoheptose) and an aliquot of fructanase are added to the sample solution. After the fructanase hydrolysis is completed, the samples are analyzed for fructose on HPAEC- PAD instrumentation. The total fructan content is calculated from the fructose, adjusted by the commodity factor, CF, determined by Part I (if not known).

AOAC Official Method 2016.06 Fructans in Infant, Pediatric, and Adult Nutritional Formulas HPAEC/PAD First Action 2016

[Applicable to the determination of the total fructan content in infant, pediatric, and adult nutritional products (as well as commodities) as defined in SMPR 2014.02 (1)]. See Tables 2016.06A–C for matrixes for which SLV data has been generated, supporting acceptance of the method. A. Principle A two-part analysis is performed. Part I is a qualitative classification of the fructan present in the sample. This classification is based on rules related to presence/absence of GF 3 (nystose) and/or GF 4 (fructofuranosylnystose), specifically, and higher oligomers, generally. It groups the fructans into one of three DP ranges and allows assignment of an appropriate commodity factor for calculating the total fructan concentration based on the amount of fructose released by enzymatic hydrolysis of the fructans. Part II is the quantitative determination of the fructan-derived fructose, from which the total fructan in calculated. The sample to be analyzed is weighed and diluted with laboratory water, as appropriate. Part I of the analysis is then performed. Part II can be run in parallel, whereby an aliquot of the diluted sample is treated with sucrase to hydrolyze any sucrose present. Glucose and fructose released by the sucrase treatment, as well as inherent glucose and fructose, are then reduced to sugar alcohols by the addition of sodium borohydride. Excess borohydride is neutralized by the addition of acetic acid. Lastly, an aliquot of

Part I - Fructan Classification for Determination of Commodity Factor

B. Apparatus and Materials

(a) LC system .—One biocompatible gradient pump; biocompatible refrigerated autosampler capable of injecting 4 μL; electrochemical detector with gold electrode capable of pulsed amperometric detection. For example, Dionex ICS-3000 or 5000 (Dionex Corp., Sunnyvale, CA) consisting of an SP, DP, WPS-3000 (TB; P or S type), and an electrochemical cell with a conventional gold working electrode and combination pH Ag/AgCl reference electrode or equivalent. (b)  Analytical column set.— Analytical column, Thermo CarboPac PA1, 250 × 4 mm PA1 guard column. (c) Analytical balance.— Readable to 0.01 mg. (d)  Syringe filter.— 0.45 µm nylon. (e)  Volumetric flasks .— Glass, Class A, assorted sizes. (f)  Eluent filtration apparatus with disposable membrane filter .— 0.2 μm polyethersulfone (PES). (g)  Helium sparge .— Tubing and frit assembly.

Table 2016.06C. Total fructan single-laboratory validation data: Recovery from spiked SPIFAN placebo samples Sample type No. of replicates a Spiking material b Spike level, g/100 g RTF Avg. % rec. RSD, % Infant formula powder partially hydrolyzed soy based 6 Inulin 0.120 97.4 4.25 Infant formula powder partially hydrolyzed soy based 6 Inulin 0.353 102 4.25 Adult nutritional powder low fat 6 Oligofructose/inulin 0.133 98.1 4.65 Adult nutritional powder low fat 6 Oligofructose/inulin 0.378 95.9 3.82 a  Duplicates on each of 3 days. b  Inulin = Beneo Orafti HP powder (SPIFAN kit). Oligofructose/inulin = Beneo Orafti Synergy 1.