Measurement of total, resistant, digestible and damaged starch in food and feed

In this chapter, methods for the measurement of total starch, resistant starch, digestible starch and damaged/gelatinized starch in grains, cereal and vegetable products and processed foods are detailed. The importance of these measurements in grain processing and utilization and in human nutrition are highlighted. AOAC Method 996.11 for total starch measurement has been modified and simplified. The method is accurate, reliable and robust and can be used for the measurement of starch in all samples, including cereal grains, food products and more difficult matrices such as corn fiber bagasse recovered from ethanol production processes. AOAC Method 2002.02 has been used as the standard method for measurement of resistant starch for over 20 years. A recommended update of this method to make the incubation conditions consistent with those employed in the most recent total dietary fiber (AOAC Method 2017.16/2022.01) and available carbohydrates procedures (AOAC Method 2020.07) is discussed. This procedure has been further modified by using thermostable α-amylase with AMG to hydrolyze the resistant starch fraction of chemically modified resistant starch (RS4). Finally, details of a widely employed enzymatic procedure for measurement of damaged starch is described. This method (AACC Method 76-31.01/ICC Method No. 164) allows accurate measurement of physically damaged starch granules in milled grain, and of hydrothermally damaged/gelatinized starch in extruded cereal products.