Measurement of Sugars and Starches in Foods by a Modification of the AOAC Total Dietary Fiber Method

Abstract A separation scheme for the determination of sugars and starch in processed food was developed. It is based on AOAC Method 985.29 for total dietary fiber with these modifications: carbohydrate starches are separated into soluble and insoluble fractions before they are hydrolyzed; acetonitrile is used instead of ethanol to separate sugars from enzyme-resistant carbohydrates, proteins, and other macromolecules; and a solid-phase extraction filter is included to remove substances that interfere with high-performance liquid chromatography (HPLC). Recovery studies indicate a >97% sugar recovery. Twenty foods were analyzed. After enzymatic hydrolysis, fructose, glucose, sucrose, maltose, and lactose were extracted and determined by HPLC using a refractive index detector. Starch content was calculated from the increase in the amount of glucose. The results were compared with values listed on the “Nutrition Facts” panel for that food. The analyzed amounts of sugars and starches were 73–96% of declared values.

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A Simplified Modification of the AOAC Official Method for Determination of Total Dietary Fiber Using Newly Developed Enzymes: Preliminary Interlaboratory Study

Journal of AOAC International ◽

10.1093/jaoac/90.1.225 ◽

2007 ◽

Vol 90 (1) ◽

pp. 225-237 ◽

Cited By ~ 6

Author(s):

Kenichiro Kanaya ◽

Shusaku Tada ◽

Bunpei Mori ◽

Rie Takahashi ◽

Sachie Ikegami ◽

...

Keyword(s):

Dietary Fiber ◽

Enzymatic Digestion ◽

Interlaboratory Study ◽

Total Dietary Fiber ◽

Stabilizing Agents ◽

Modified Method ◽

Relative Standard ◽

Aoac Method ◽

Standard Deviations

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 α-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 α-amylase stabilizing agents to the reaction system.

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Urea Enzymatic Dialysis Procedure for Determination of Total Dietary Fiber

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/72.4.677 ◽

1989 ◽

Vol 72 (4) ◽

pp. 677-681

Author(s):

Joseph L Jeraci ◽

Betty A Lewis ◽

J Peter ◽

Van J Soest ◽

James B Robertson

Keyword(s):

Dietary Fiber ◽

Crude Protein ◽

Gravimetric Method ◽

New Method ◽

Locust Bean Gum ◽

Total Dietary Fiber ◽

Insoluble Dietary Fiber ◽

Aoac Method ◽

Locust Bean

Abstract A method that uses urea and enzymes for determination of total dietary fiber (TDF) in foods has been developed and compared with the AOAC enzymatic-gravimetric method (43.A14-43.A20). In the evaluation, results for crude protein and ash contamination were higher by the AOAC method, particularly for samples that form gels during ethanol precipitation. The new urea enzymatic dialysis (UED) method quantitatively recovered, with less variation, more of the purified and semipurified dietary fiber products. TDF recoveries for carboxymethylcellulose and locust bean gum were 98% (SD 3.3) and 95% (SD 6.1) by the AOAC method and 99% (SD 1.0) and 100% (SD 0.6) by the UED method, respectively. The UED method was the more effective in removing starch. For kale samples, starch recovery was 3.5 and 0.2% from TDF residues obtained using the AOAC and UED methods, respectively. Differences were not significant among replicate values for determination of TDF in foods by the UED method (P >0.01). Preliminary studies suggest that the new method can separately determine soluble and insoluble dietary fiber. The data indicate that the UED method is more precise and accurate than the AOAC method.

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Determination of Total Dietary Fiber (CODEX Definition) by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/93.1.221 ◽

2010 ◽

Vol 93 (1) ◽

pp. 221-233 ◽

Cited By ~ 83

Author(s):

Barry V McCleary ◽

Jonathan W De Vries ◽

Jeanne I Rader ◽

Gerald Cohen ◽

Leon Prosky ◽

...

Keyword(s):

Molecular Weight ◽

Dietary Fiber ◽

Resistant Starch ◽

Collaborative Study ◽

Gravimetric Method ◽

Low Molecular Weight ◽

Total Dietary Fiber ◽

Aoac Method ◽

Standard Deviations

Abstract A method for the determination of total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official MethodsSM 985.29, 991.43, 2001.03, and 2002.02, the method quantitates high- and low-molecular-weight dietary fiber (HMWDF and LMWDF, respectively). In 2007, McCleary described a method of extended enzymatic digestion at 37C to simulate human intestinal digestion followed by gravimetric isolation and quantitation of HMWDF and the use of LC to quantitate low-molecular-weight soluble dietary fiber (LMWSDF). The method thus quantitates the complete range of dietary fiber components from resistant starch (by utilizing the digestion conditions of AOAC Method 2002.02) to digestion resistant oligosaccharides (by incorporating the deionization and LC procedures of AOAC Method 2001.03). The method was evaluated through an AOAC collaborative study. Eighteen laboratories participated with 16 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 11.57 to 47.83. Digestion of samples under the conditions of AOAC Method 2002.02 followed by the isolation and gravimetric procedures of AOAC Methods 985.29 and 991.43 results in quantitation of HMWDF. The filtrate from the quantitation of HMWDF is concentrated, deionized, concentrated again, and analyzed by LC to determine the LMWSDF, i.e., all nondigestible oligosaccharides of degree of polymerization 3. TDF is calculated as the sum of HMWDF and LMWSDF. Repeatability standard deviations (sr) ranged from 0.41 to 1.43, and reproducibility standard deviations (sR) ranged from 1.18 to 5.44. These results are comparable to other official dietary fiber methods, and the method is recommended for adoption as Official First Action.

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Determination of Total Dietary Fiber in Japanese Foods

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/74.2.350 ◽

1991 ◽

Vol 74 (2) ◽

pp. 350-359 ◽

Cited By ~ 2

Author(s):

Takahiro Nishimune ◽

Tatsuo Sumimoto ◽

Tsumoru Yakusiji ◽

Nobuharu Kunita ◽

Tomio Ichikawa ◽

...

Keyword(s):

Dietary Fiber ◽

Colorimetric Method ◽

Total Dietary Fiber ◽

Relative Standard ◽

Kjeldahl Method ◽

Aoac Method ◽

Fiber Components ◽

Unsuitable Samples ◽

Fiber Sample

Abstract Total dietary fiber was determined In Japanese foods by the Prosky-AOAC method. To accomplish the analyses of unsuitable samples, we Introduced a few minor modifications to the versions for (I) seaweed and fruits, (II) cereals, and (ill) fish and meats. These modified methods were used together with the standard method to obtain results with reasonably good relative standard deviation for 231 foods and 21 groups of mixed foods. In this study, dietary fiber was defined so as not to exclude the nondlgestlble polysaccharide portions of animal foods. A method was proposed which could estimate more accurately the fiber components of animal foods by measuring the "nondlgestlble protein" of the fiber sample by the Biuret colorimetric method, Instead of the Kjeldahl method, to avoid deducting the values for aminopolysaccharides. In Japanese diets, the amount of fiber obtained from animal foods was less than 5 % of the total Intake of dietary fiber.

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A Simplified Modification of the AOAC Official Method for Determination of Total Dietary Fiber Using Newly Developed Enzymes

Journal of AOAC International ◽

10.1093/jaoac/90.1.217 ◽

2007 ◽

Vol 90 (1) ◽

pp. 217-224 ◽

Cited By ~ 3

Author(s):

Shusaku Tada ◽

Satoshi Innami

Keyword(s):

Dietary Fiber ◽

Corn Starch ◽

Enzymatic Digestion ◽

Soluble Starch ◽

Wheat Starch ◽

Official Method ◽

Total Dietary Fiber ◽

Modified Method ◽

Aoac Method

Abstract Since 1985, AOAC Method 985.29 has been globally adopted as a standard method for determination of total dietary fiber in foods. Nevertheless, an aspect of AOAC Method 985.29 that needs to be improved is the laborious process to treat 3 enzymes separately at their individual proper pH, which is quite time-consuming. Several examinations have been carried out to resolve this problem. The characteristics of newly developed thermostable -amylase, neutral protease, and amyloglucosidase were evaluated based on the pH-activity profile and the property of starch hydrolysis in comparison with those of the conventional enzyme reagents. These 3 developed enzymes were found to work under the same pH condition and to accomplish sufficient digestion for the typical 3 starches: soluble starch, corn starch, and wheat starch. The experimental results revealed that the dietary fiber determination in foods could be performed without pH adjustment in the enzymatic digestion process. The modified method will be greatly helpful in determining the total dietary fiber contents in food materials with less laborious work and with an accuracy equivalent to that of AOAC Method 985.29.

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