When you analyse a dried sample, the result obtained after the analysis is expressed in % of dry sample (g/100g).
If values are to be expressed in % of the original sample before drying, they will need to be adjusted backwards.
If the result is 2 % (g/100g) in dry material, and loss due to drying is 20% then the starch per 100 g of as is material (as received) will be calculated as follows:
Total starch in dry sample (2 %) x (100 – % loss on drying (20) ) /100 = 1.6 %.