AOAC RI ERP E-Book - DS DF

OMA 2014.10 C: Collaborative Study Manuscript Expert Review Panel Use Only September, 2017

2013 Dietary Starch in Animal Feeds Collab Study Protocol 072513

Dietary Starch Assay flow chart

W E : Samples for Enzymatically-Released + Free Glucose Analysis

W F : Samples for Free Glucose Analysis

Test and Control Sample Portions and Blanks (in duplicate tubes)

Test and Control Sample Portions and Blanks (in duplicate tubes)

Add 30 mL Na acetate buffer

Add 30 mL Na acetate buffer and heat-stable, alpha-amylase.

Vortex. Incubate 1 h at 100°C. Vortex at 10, 30 and 50 min.

Vortex. Incubate 1 h at 100°C. Vortex at 10, 30 and 50 min.

Add 20 ml water,

Cool on bench 0.5 h.

Invert tubes >4 x to mix completely.

Add diluted amyloglucosidase.

Vortex. Incubate 2 h at 50°C. Vortex at 1 h. Invert tubes >4 x to mix completely.

Add 20 ml water

Procedure for Final Volume by Volumetric Flasks

Procedure for Final Volume by Sum of Volume Additions

Test Solutions

Centrifuge portion at 1000 x g for 10 min (if still cloudy, centrifuge 10 min at 10,000 x g ).

Quantitatively transfer and filter test solution into a 100 mL volumetric flask.

In duplicate, pipette 0.1 mL working standards and test solutions into 16 x 100 mm glass tubes, add 3.0 mL GOPOD. Prepare 1 in 5 dilutions as needed or analyze test solutions directly. AOAC Research Institute ERP Use Only Prepare 1 in 10 dilutions as needed or analyze test solutions directly. Vortex. cover tubes with plastic film to seal. Incubate in a 50°C waterbath for 20 min.

Solutions with Developed Chromogen

Read absorbance on a spectrophotometer.

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