ANKOM TDF Dietary - Manual (Page 92)

Operator’s Manual
pg. 92
Rev E 12/2/14
Appendix C – De-fatting Procedure
According to the AOAC 985.29E method (and referred to in the AOAC 991.43 method), any sample with a fat content ˃10%
must have the fat removed before determining the amount of Dietary Fiber.
In the conventional method, most labs perform the de-fatting step in the same beaker in which the enzyme digestion occurs.
While this method would work with the ANKOM
TDF
Dietary Fiber Analyzer, many would find transferring the sample from the
beaker into the IDF or IDF Flow-Thru bags less than efficient. As a result, we have developed a de-fatting method using an
ANKOM XT4 Filter Bag in an effort to eliminate sample loss.
The XT4 Filter Bag is used in the ANKOM XT Fat Extractors. The bag has a
porosity of 1-4 microns. As a result, the likelihood of sample loss is eliminated.
To de-fat your sample prior to running the IDF/SDF or TDF analyses, follow the steps below.
1. Number all of the XT4 Filter Bags to be used for testing.
2. Record the weight of each XT4 Filter Bag.
It is important to note that the weight of the XT4 Filter Bag must be included in
the analysis calculations in the following ways:

For an IDF/SDF analysis, add the weight of the XT4 bag to the weight of
the IDF bag.

For a TDF analysis, add the weight of the XT4 bag to the weight of the
SDF bag.
3. Record the weight of each sample to be de-fatted in the appropriate
XT4 Filter Bags.
4. Heat seal the Filter Bags.
With the heat sealer set at 5-6, seal the Filter Bag within 4mm of its open end. Be sure
to hold the sealer arm down for 2-3 seconds after the red sealer light turns off to
properly cool the seal.