The sample preparation method is chosen based on the known composition of the sample to be analysed.
If you are unsure of the sample composition the following may be helpful:
To determine if your sample contains resistant starch you can run both method (A) and method (B) - if you observe an increased result with method (B) then you can conclude that the sample contains resistant starch, and you should proceed with method B for that sample.
If you are unsure what else is in your sample (E.G. free-glucose, maltodextrins..) then it is recommended you include the ethanol washing step described on Pg 13 method (E) of the data booklet. Then proceed as per method (A) or (B).
If you do not plan to run the ethanol washing step, ensure a blank as described on Pg 8 is run which will indicate if the sample contains any free glucose.