In order to determine which method to follow, first assess whether the sample has a high free glucose content.
This can be achieved by analysing a sample blank. Using the standard assay procedure (Method A), instead of adding enzymes, add buffer at these incubation steps and then measure by GOPOD.
If the free glucose content is high we would recommend that you include the ethanol washing steps by following method (E) on page 13 of the data booklet.
If the free glucose is low then we would recommend running method A or B, depending on whether the sample contains resistant starch or not.
Alternatively, the need to perform this sample blank analysis can be avoided by washing of samples with aqueous ethanol (80%) [see example (E) in the data booklet]. This is the most simple approach if unsure which method to use.
If you are unsure if your sample contains resistant starch, you should run both method (A) and method (B) - if you observe an increased result with method (B) then you can conclude that your sample contains resistant starch.