title: A simplified modification of the AOAC official method for determination of total dietary fiber using newly developed enzymes: preliminary interlaboratory study.
abstract: A preliminary interlaboratory study was conducted to evaluate the validity of the modified AOAC method for determination of total dietary fiber by Tada and Innami, in which the 3-step enzymatic digestion process in AOAC Method 991.43 is modified to a 2-step process without pH adjustment. Total dietary fiber contents in 8 representative foodstuffs were measured using both the original AOAC Method 991.43 and the modified method in 6 research facilities in Japan. Repeatability relative standard deviations, reproducibility relative standard deviations, and Horwitz ratio values from the modified method were equivalent to those from AOAC Method 991.43, except in the rice sample. However, this exceptional case shown in the modified method was entirely dissolved by the addition of alpha-amylase stabilizing agents. The modified method, which shortens the process of enzymatic digestion from 3 to 2 steps and in which only reaction temperature is adjusted under the same pH, was found not only to give accurate values comparable to the original method, but also to substantially reduce the labor required by the laboratory staff in the process of routine analysis. This study revealed that the validity of the modified method was further ensured by adding alpha-amylase stabilizing agents to the reaction system.
authors: Japan Food Research Laboratories, 52-1, Motoyoyogi-cho, Shibuya-ku, Tokyo, 151-0062, Japan. kanayak@jfrl.or.jp
authors: Kenichiro
authors: K
authors: Kanaya
authors: Shusaku
authors: S
authors: Tada
authors: Bunpei
authors: B
authors: Mori
authors: Rie
authors: R
authors: Takahashi
authors: Sachie
authors: S
authors: Ikegami
authors: Shin'ichi
authors: S
authors: Kurasawa
authors: Masami
authors: M
authors: Okuzaki
authors: Yoko
authors: Y
authors: Mori
authors: Satoshi
authors: S
authors: Innami
mesh_terms: D003296:Cooking; D004043:Dietary Fiber / Q000032:analysis*; D004795:Enzyme Stability; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism; D006801:Humans; D010447:Peptide Hydrolases / Q000378:metabolism; D027805:Phaseolus / Q000737:chemistry; D015203:Reproducibility of Results; D000516:alpha-Amylases / Q000378:metabolism
chemical_list: D004043:Dietary Fiber; D000516:alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase; D010447:Peptide Hydrolases