Determination Trial of Nondigestible Oligosaccharide in Processed Foods by Improved AOAC Method 2009.01 Using Porcine Small Intestinal Enzyme.

We have previously shown that the Association of Official Analytical Chemists' (AOAC) methods 2001.03 and 2009.01 were not able to measure accurately nondigestible oligosaccharide because they are incapable of hydrolyzing digestible oligosaccharide, leading to overestimation of nondigestible oligosaccharide. Subsequently, we have proposed improved AOAC methods 2001.03 and 2009.01 using porcine small intestinal disaccharidases instead of amyloglucosidase. In the present study, we tried to determine nondigestible oligosaccharide in marketed processed foods using the improved AOAC method (improved method), and the results were compared with those by AOAC method 2009.01. In the improved method, the percentages of recovery of fructooligosaccharide, galactooligosaccharide, and raffinose to the label of processed food were 103.0, 89.9, and 102.1%, respectively. However, the AOAC method 2009.01 overestimated >30% of the quantity of nondigestible oligosaccharide in processed foods, because the margin of error was accepted ±20% on the contents of nondigestible oligosaccharides in processed foods for Japanese nutrition labeling, the improved method thus provided accurate quantification of nondigestible oligosaccharides in processed food and allows a comprehensive determination of nondigestible oligosaccharides.