Why are my Crude Fat results high?

There are three primary reasons for high Crude Fat results.

(1) The bag is not completely sealed; therefore the sample gets lost during extraction.

(2) A bag picks up surface fat from another sample.

(3) Incomplete drying in the pre-extraction phase. This is the biggest contributor to high crude fat results. All the moisture in the sample must be removed before the extraction because the ANKOM technique uses the indirect method of determining fat (weighing what is left over after the fat has been extracted). It is good to regularly check your moisture (dry matter) values when performing fat extraction using ANKOM instrumentation. This can be done by simply weighing and recording the weight of the Filter Bag before filling it with the sample. After the three-hour drying step, when you re-weigh the bags plus the sample, the following formula will give you the moisture value:  

100 x ((Filter Bag Weight + Sample Weight) - Weight After Drying) / Sample Weight

We suggest each lab regularly test this analysis by utilizing a check sample or lab standard. Low moisture values tend to be due to:

• Not using or incorrectly using desiccant pouches
• Incorrect oven temperature settings (should be between 100 - 105°C)
• Hot or cold spots in the oven
• The oven is being overloaded with other samples or glassware