Phosphate cross-linked starch, referred to as resistant starch 4 (RS4) is hydrolyzed much more rapidly under physiological conditions (i.e., pH 6, 37°C, pancreatic α-amylase) than under the conditions used in AOAC dietary fiber method 985.29/AACC International Approved Method 32-45.01 (the Prosky method), in which samples are incubated with thermostable bacterial α-amylase at 95–100°C. For this reason, the author concludes that the Prosky method overestimates the dietary fiber content of these materials. A more accurate estimate of dietary fiber content is obtained with AOAC Method 2009.01/AACCI Approved Method 32-45.01.
