Enzymatic/Chemical Analysis of Dietary Fiber

Abstract The Uppsala methodology for rapid analysis and characterization of total dietary fiber, defined as the sum of dietary fiber polysaccharides (DFP) and Klason lignin, was studied. A sugar- and starch-free residue was prepared by treatment with a thermo-stable amylase and amyloglucosidase. Neutral DFP residues were quantified by gas chromatography as alditol acetates after acid hydrolysis of this residue, and the acidinsoluble fraction, Klason lignin, was determined gravimetricaliy. Uronic acid residues were quantified by decarboxylation of the original sample. The efficacy of the Uppsala methodology was tested with foods varying in fiber content and composition, including heat-treated samples. The present method allowed the analysis of up to 40 samples per week. It had good repeatability and coefficients of variation of 3-5% for the main fiber components. Fiber contents determined with the method were higher than those determined with a similar method that excludes Klason lignin and starch resistant to amylases but soluble in dimethyl sulfoxide and lower than those determined with an enzymatic/gravimetric method. Important aspects of fiber analysis, like enzyme purity and the recovery of soluble fiber on ethanol precipitation, also were investigated.

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Enzymatic-Gravimetric Determination in Foods of Dietary Fiber as Sum of Insoluble and Soluble Fiber Fractions: Summary of Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/76.4.923 ◽

1993 ◽

Vol 76 (4) ◽

pp. 923-925 ◽

Cited By ~ 21

Author(s):

Roger Mongeau ◽

Rene Brassard

Keyword(s):

Dietary Fiber ◽

Collaborative Study ◽

Gravimetric Method ◽

Wheat Bread ◽

Soluble Fiber ◽

Total Dietary Fiber ◽

Whole Wheat ◽

Whole Wheat Bread ◽

Relative Standard ◽

Fiber Fractions

Abstract A collaborative study was conducted on an enzymatic- gravimetric method for determination of total dietary fiber in foods, in which soluble fiber and insoluble fiber are determined separately. Ten collaborators analyzed blind duplicate test samples from 5 food products: turnip, wheat bran, beans canned with tomato sauce, rice, and whole wheat bread. Repeatability and reproducibility relative standard deviations ranged from 1.48 to 14.73% and from 4.13 to 17.94%, respectively. The method was adopted first action by AOAC International.

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Effect of Milling Procedure on the Measurement of Dietary Fiber by a Gravimetric Method

Journal of AOAC International ◽

10.1093/jaoac/78.1.83 ◽

1995 ◽

Vol 78 (1) ◽

pp. 83-87

Author(s):

W John Mullin ◽

Mark S Wolynetz

Keyword(s):

Dietary Fiber ◽

Spring Wheat ◽

Gravimetric Method ◽

Soluble Fiber ◽

White Potato ◽

Total Dietary Fiber ◽

Hard Red Spring Wheat ◽

Effect Of Particle Size ◽

The Difference

Abstract Samples of white potato, sweet potato, hard red spring wheat, soft white winter wheat, and soft wheat bran were ground in a Wiley mill or a Cyclotec mill. A significantly (p < 0.0001) larger proportion of coarse material (>75μ) resulted from the Wiley mill, and a significantly (p < 0.0001) larger proportion of fine material (<45μ) was produced by the Cyclotec mill. The effect of particle size on the determination of soluble, insoluble, and total dietary fiber was less well defined. In 4 of 5 commodities tested, samples from the Cyclotec mill showed a greater amount of soluble fiber, while the reverse was true for insoluble and total fiber. The difference in total dietary fiber, with respect to the mill used in sample preparation, varied from 0.24% on a total 9.10% for potatoes to 1.00% on a total of 14.05% for hard red spring wheat.

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Total Dietary Fiber Determined as Neutral Sugar Residues, Uronic Acid Residues, and Klason Lignin (The Uppsala Method): Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/78.4.1030 ◽

1995 ◽

Vol 78 (4) ◽

pp. 1030-1044 ◽

Cited By ~ 235

Author(s):

Olof Theander ◽

Per Åman ◽

Eric Westerlund ◽

Roger Andersson ◽

Dan Pettersson

Keyword(s):

Dietary Fiber ◽

Uronic Acid ◽

Free Acid ◽

Collaborative Study ◽

Gravimetric Method ◽

Insoluble Residue ◽

Gas Liquid Chromatography ◽

Neutral Sugar ◽

Klason Lignin ◽

Total Dietary Fiber

Abstract A joint AOAC/American Association of Cereal Chemists (AACC) collaborative study was conducted to determine by the Uppsala method the dietary fiber content and its composition in various foods. The method includes preparation of a residue by treatment with thermostable α-amylase and amyloglucosidase and then ethanol precipitation of solubilized dietary fiber components while leaving low-molecular weight carbohydrates in solution. After acid hydrolysis of residue, neutral polysaccharide residues are determined as alditol acetates by gas-liquid chromatography, uronic acid residues are determined by colorimetry, and ash-free acid-insoluble residue (Klason lignin) is determined gravimetrically. Total dietary fiber, including enzyme-resistant starch, is calculated as the sum of nonstarch polysaccharide residues and Klason lignin. Nine laboratories completed the study, analyzing in duplicate 8 unknown dried products that included 4 cereal products, green peas, potato fiber, carrots, and apples. Total dietary fiber contents of products tested ranged from 4.6 to 84.3%, with an average RSDR value of 8.4% (range, 4.8–11.1%). Total neutral polysaccharide residues ranged from 3.8 to 64.1%, with an average RSDR value of 7.5% (range, 5.4–10.5%). Individual neutral sugars (rhamnose, arabinose, xylose, mannose, galactose, and glucose) and uronic acid residues present at more than 1% generally had good RSDR values (3.3– 22.8%), whereas, as expected for Klason lignin, only the wheat bran sample with a high content (16%) had an excellent RSDR value (5.0%). The gas chromatographic-colorimetric-gravimetric method (Uppsala method) for determination of total dietary fiber (as neutral sugar residues, uronic acid residues, and Klason lignin) has been adopted first action by AOAC INTERNATIONAL.

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Determination of Total, Soluble, and Insoluble Dietary Fiber in Foods—Enzymatic-Gravimetric Method, MES-TRIS Buffer: Collaborative Study

Journal of AOAC International ◽

10.1093/jaoac/75.3.395 ◽

1992 ◽

Vol 75 (3) ◽

pp. 395-416 ◽

Cited By ~ 161

Author(s):

Sungsoo C Lee ◽

Leon Prosky ◽

Jonathan W De Vries

Keyword(s):

Dietary Fiber ◽

Collaborative Study ◽

Gravimetric Method ◽

Tris Buffer ◽

Total Dietary Fiber ◽

Method Performance ◽

Insoluble Dietary Fiber ◽

Heat Stable ◽

Assay Precision

Abstract A joint AOAC/AACC (American Association of Cereal Chemists) collaborative study of methods for the determination of soluble, insoluble, and total dietary fiber (SDF, IDF, and TDF) was conducted with 11 participating laboratories. The assay Is based on a modification of the AOAC TDF method 985.29 and the SDF/IDF method collaboratively studied recently by AOAC. The principles of the method are the same as those for the AOAC dietary fiber methods 985.29 and 991.42, Including the use of the same 3 enzymes (heat-stable α-amylase, protease, and amyloglucosldase) and similar enzyme Incubation conditions. In the modification, minor changes have been made to reduce analysis time and to Improve assay precision: (1) MES-TRIS buffer replaces phosphate buffer; (2) one pH adjustment step Is eliminated; and (3) total volumes of reaction mixture and filtration are reduced. Eleven collaborators were sent 20 analytical samples (4 cereal and grain products, 3 fruits, and 3 vegetables) for duplicate blind analysis. The SDF, IDF, and TDF content of the foods tested ranged from 0.53 to 7.17, 0.59 to 60.53, and 1.12 to 67.56 g/100 g, respectively. The respective average RSDR values for SDF, IDF, and TDF determinations by direct measurements were 13.1, 5.2, and 4.5%. The TDF values calculated by summing SDF and IDF were in excellent agreement with the TDF values measured independently. The modification did not alter the method performance with regard to mean dietary fiber values, yet It generated lower assay variability compared with the unmodified methods. The method for SDF, IDF, and TDF (by summing SDF and IDF) has been adopted first action by AOAC International.

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Dietary fiber intake and risk of prediabetes in China: results from the TCLSIH Cohort Study

British Journal Of Nutrition ◽

10.1017/s0007114521003779 ◽

2021 ◽

pp. 1-20

Author(s):

Shunming Zhang ◽

Ge Meng ◽

Qing Zhang ◽

Li Liu ◽

Zhanxin Yao ◽

...

Keyword(s):

Cohort Study ◽

Dietary Fiber ◽

Lower Risk ◽

Fiber Intake ◽

Soluble Fiber ◽

Total Dietary Fiber ◽

Dietary Fiber Intake ◽

Cox Proportional Hazard ◽

Hazard Ratios ◽

Cox Proportional Hazard Models

Abstract High dietary fiber intake has been associated with a lower risk of diabetes, but the association of dietary fiber with prediabetes is only speculative, especially in China, where the supportive data from prospective studies is lacking. This study aimed to examine the association between dietary fiber intake and risk of incident prediabetes among Chinese adults. We performed a prospective analysis in 18,085 participants of the TCLSIH cohort study who were free of diabetes, prediabetes, cancer, and cardiovascular disease at baseline. Dietary data were collected using a validated 100-item food frequency questionnaire. Prediabetes was defined based on the American Diabetes Association diagnostic criteria. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During 63,175 person-years of follow-up, 4,139 cases of incident prediabetes occurred. The multivariable HRs (95% CIs) of prediabetes for the highest versus lowest quartiles were 0.85 (0.75, 0.98) (P for trend =0.02) for total dietary fiber, 0.84 (0.74, 0.95) (P for trend <0.01) for soluble fiber, and 1.05 (0.93, 1.19) (P for trend =0.38) for insoluble fiber. Fiber from fruits, but not from cereals, beans, and vegetables was inversely associated with prediabetes. Our results indicate that intakes of total dietary fiber, soluble fiber, and fiber derived from fruit sources were associated with a lower risk of prediabetes.

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Total Dietary Fiber--Rapid Gravimetric Method

AACC International Approved Methods ◽

10.1094/aaccintmethod-32-06.01 ◽

2009 ◽

Author(s):

AACC Technical

Keyword(s):

Dietary Fiber ◽

Gravimetric Method ◽

Total Dietary Fiber

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Simplified Method for Determination of Total Dietary Fiber in Foods

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/71.5.1063 ◽

1988 ◽

Vol 71 (5) ◽

pp. 1063-1064

Author(s):

Betty W Li ◽

Karen W Andrews

Keyword(s):

Dietary Fiber ◽

Incubation Period ◽

Gravimetric Method ◽

Food Samples ◽

Total Dietary Fiber ◽

Collaborative Studies ◽

Simplified Method ◽

Good Agreement

Abstract A simplified method, based on the same principles as the AOAC enzymatic-gravimetric method for determining total dietary fiber (TDF) (43.A14-43.A20), has been tested on 12 food samples which had been used in other collaborative studies. TDF values obtained in our laboratory for these 2 methods were in good agreement (y = 0.96x + 0.39; r = 0.999). The simplified method uses a single incubation period and only 1 enzyme (amyloglucosidase), and thus yields smaller blank and ash corrections but a higher protein correction.

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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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