Determination of Water-Insoluble Cell Walls in Feeds: Interlaboratory Study

1989 ◽  
Vol 72 (3) ◽  
pp. 463-467 ◽  
Author(s):  
Bernard Carré ◽  
Jean-Marc Brillouet
Keyword(s):  
Cell Wall ◽  
Dietary Fiber ◽  
Collaborative Study ◽  
Sodium Dodecylsulfate ◽  
Neutral Detergent Fiber ◽  
Total Dietary Fiber ◽  
Insoluble Dietary Fiber ◽  
Heat Stable ◽  
Coefficients Of Variation

Abstract A collaborative study was conducted to test a new rapid procedure for determination of water-insoluble cell wall (WICW) content in feeds. In the method, starch is solubilized near boiling temperature with Termamyl, a heat-stable alpha-amylase, and proteins are solubilized at 40 °C with sodium dodecylsulfate and Pronase. Then, the organic matter of the residue is determined by incineration. Three hours were required to treat 12 different samples, including solubilization treatments, filtrations, and rinses. Eleven unknown products including 9 common feedstuffs of various origin and 2 mixed diets for poultry were analyzed by 7 analysts in France. Coefficients of variation ranged from 2.3 to 6.1%. The results were compared to those for water-insoluble dietary fiber (WIDF), total dietary fiber, and neutral detergent fiber. Agreement was best with the water-insoluble dietary fiber procedure. For most samples, the ratios of WIDF/WICW ranged from 0.981 to 0.842. The differences between WICW and WIDF values correspond to cell wall protein which is accounted for in WICW, but not in WIDF.

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

1992 ◽  
Vol 75 (3) ◽  
pp. 395-416 ◽  
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.

Determination of Insoluble and Soluble Dietary Fiber in Foods and Food Products: Collaborative Study

1992 ◽  
Vol 75 (2) ◽  
pp. 360-367 ◽  
Author(s):  
Leon Prosky ◽  
Nils-Georg Asp ◽  
Thomas F Schweizer ◽  
Jonathan W Devries ◽  
Ivan Furda
Keyword(s):  
Dietary Fiber ◽  
Collaborative Study ◽  
Dry Weight ◽  
Food Products ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Brussels Sprouts ◽  
Insoluble Dietary Fiber ◽  
Relative Standard

Abstract A collaborative study was conducted to validate a method to determine the Insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) contents of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that for determining total dietary fiber, which was adopted as final action by AOAC and further modified to Include changes in the concentration of buffer and base and substitution of hydrochloric acid for phosphoric acid. Thirty-nine collaborators were each sent 7 test samples In a staggered design for duplicate blind analysis. They were also sent a standard containing 4.3-5.4% IDF and 1.5-2.7% SDF. The 22 foods that were analyzed for IDF and SDF were cabbage, carrots, French beans, kidney beans, butter beans, okra, onions, parsley, chick peas, brussels sprouts, barley, rye flour, turnips, soy bran, wheat germ, raisins, Callmyrna figs, prune powder, Black Mission figs, apple powder, peach powder, and apricot powder. Both IDF and SDF values were calculated as the weight of residue minus the weight of protein and ash reported on a dry weight basis. The reproducibility relative standard deviation (RSDR) of the IDF results ranged from 3.68 to 19.44% for the foods analyzed; almost half the test samples had an RSDR <10%. The RSDR values for the SDF results were somewhat higher. Approximately 50% of the foods analyzed had an RSDR >20%, and 45% had an RSDR between 10 and 20%. An RSDR approaching 45% was calculated for the 2 test samples with the lowest SDF content, 1.35 and 1.90%. Raisins and prune powder had high RSDR values for both SDF and IDF. A major reason for high RSDR values seems to be filtration problems, which are avoidable by analyzing 0.5-0.25 g test samples. The method for the determination of SDF requires further study, but the method for the determination of IDF was adopted first action by AOAC International.

Determination of Total Dietary Fiber in Foods, Food Products, and Total Diets: Interlaboratory Study

1984 ◽  
Vol 67 (6) ◽  
pp. 1044-1052 ◽  
Author(s):  
Leon Prosky ◽  
Nils-Georg Asp ◽  
Ivan Furda ◽  
Jonathan W Devries ◽  
Thomas F Schweizer ◽  
...  
Keyword(s):  
Dietary Fiber ◽  
Food Products ◽  
The Other ◽  
Interlaboratory Study ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Heat Stable ◽  
Coefficients Of Variation ◽  
The Individual

Abstract An interlaboratory study was conducted to determine the total dietary fiber (TDF) content of food, food products, and total diets, using a combination of enzymatic and gravimetric procedures. Thirteen unknown products including 2 mixed diets (one lacto-ovo vegetarian and the other nonvegetarian) were analyzed by 32 analysts. Duplicate samples of dried foods were gelatinized with Termamyl, a heat-stable alphaam) lase, and then enzymatically digested with protease and amyloglucosidase to remove the protein and starch present in the sample. Four volumes of 95% ethanol were added to precipitate the soluble dietary fiber. The total residue was filtered, and then washed with 74% ethanol, 95% ethanol, and acetone. After drying, the residue was weighed. One of the duplicates was analyzed for protein, and the other was ashed at 525°C and the ash was measured. TDF was calculated as the weight of the residue less the weight of protein and ash. Coefficients of variation for 10 of the samples ranged from 2.95 to 26.39%. For 3 of the samples high coefficients of variation were obtained. The results compared satisfactorily with those obtained previously by the best method available for the individual foods studied.

Determination of Soluble Dietary Fiber in Foods and Food Products: Collaborative Study

1994 ◽  
Vol 77 (3) ◽  
pp. 690-694 ◽  
Author(s):  
Leon Prosky ◽  
Nils-Georg Asp ◽  
Thomas F Schweizer ◽  
Jonathan W Devries ◽  
Ivan Furda ◽  
...  
Keyword(s):  
Dietary Fiber ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Food Products ◽  
Green Beans ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Insoluble Dietary Fiber ◽  
Relative Standard

Abstract A collaborative study was conducted to determine the soluble dietary fiber (SDF) content of foods and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that employed for determining total dietary fiber (TDF), 985.29, and the method for insoluble dietary fiber (IDF), 991.42. Ten laboratories were each sent 13 test samples (6 blind duplicates and 1 standard [green beans] containing 29-33% TDF, 19-23% IDF, and 8-13% SDF) and were instructed to assay for IDF, SDF, and TDF independently. Included in the package were the 3 enzymes, namely alpha-amylase, amyloglucosidase, and protease, and the filter aid Celite, which was thought to be the major cause of high reproducibility relative standard deviation (RSDR) values for SDF obtained in a previous collaborative study. The foods to be analyzed were apricots, carrots, chickpeas, onions, raisins, and the sugar beet fiber Fibrex™. IDF, TDF, and SDF were calculated as the weight of residue minus the weight of protein and ash on a dry weight basis. RSDR values of the IDF results averaged 8.02%, with only 1 food having an RSDR >10%. The RSDR values for the TDF results averaged 4.97%, and all foods had an RSDR <7%. Although the RSDR values for SDF averaged 14.17%, 4 of the 6 foods had an RSDR <10%, and 1 of the 2 remaining foods that had a high RSDR had an SDF content of only 1.2%. In all cases, the RSDR values of the SDF content of the foods were less than the values for the same foods analyzed in a previous collaborative trial. The enzymatic-gravimetric method for the determination of SDF was adopted first action by AOAC INTERNATIONAL.

Determination of Insoluble, Soluble, and Total Dietary Fiber in Foods and Food Products: Interlaboratory Study

1988 ◽  
Vol 71 (5) ◽  
pp. 1017-1023 ◽  
Author(s):  
Leon Prosky ◽  
Nils-Georg Asp ◽  
Thomas F Schweizer ◽  
Jonathan W Devries ◽  
Ivan Furda
Keyword(s):  
Hydrochloric Acid ◽  
Phosphoric Acid ◽  
Dietary Fiber ◽  
Collaborative Study ◽  
Food Products ◽  
Separate Determination ◽  
Total Dietary Fiber ◽  
Insoluble Dietary Fiber ◽  
Soy Isolate

Abstract A collaborative study was conducted to determine the insoluble dietary fiber (IDF), soluble dietary fiber (SDF), and total dietary fiber (TDF) content of food and food products by using a combination of enzymatic and gravimetric procedures. The method was basically the same as that developed for TDF only, which was adopted official final action by AOAC, except for changing the concentration of buffer and base and substituting hydrochloric acid for phosphoric acid. These changes were made to improve the robustness of the method. Duplicate blind samples of soy isolate, white wheat flour, rye bread, potatoes, rice, corn bran, oats, Fabulous Fiber, wheat bran, and a high fiber cereal were analyzed by 13 collaborators. Dietary fiber values (IDF, SDF, and TDF) were calculated as the weight of residue minus the weight of protein and ash. The coefficients of variation (CVs) of both the independent TDF determination and the sum of IDF and SDF were better than 15 and 18%, respectively, with the exception of rice and soy isolate. These 2 foods, however, contained only about 1% TDF. The CVs of the IDF were equally good, except for Fabulous Fiber, for which filtration problems occurred. The CVs for the SDF were somewhat high, but these products had very low SDF content. There was excellent agreement between the TDF determined independently and the TDF determined by summing the IDF and SDF. The method for separate determination of IDF and SDF requires further study. The modifications (changes in concentration of buffer and base and the use of hydrochloric acid instead of phosphoric acid) to the official final action method for TDF have been adopted.

Urea Enzymatic Dialysis Procedure for Determination of Total Dietary Fiber

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.

scholarly journals Determination of Total Dietary Fiber in Selected Foods Containing Resistant Maltodextrin by Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study

2002 ◽  
Vol 85 (2) ◽  
pp. 435-444 ◽  
Author(s):  
Dennis T Gordon ◽  
Kazuhiro Okuma ◽  
J W DeVries ◽  
K Fukuhara ◽  
W Jacob ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Dietary Fiber ◽  
Average Molecular Weight ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Resistant Maltodextrin ◽  
Standard Deviations

Abstract A method was developed for determination of total dietary fiber (TDF) in foods containing resistant maltodextrin (RMD) which includes nondigestible carbohydrates that are not fully recovered as dietary fiber by conventional TDF methods such as AOAC 985.29 or 991.43. Because the average molecular weight (MW) of RMD is 2000 daltons, lower MW soluble dietary fiber components do not precipitate in 78% ethanol; therefore, RMD is not completely quantitated as dietary fiber by current AOAC methods. The accuracy and precision of the method was evaluated through an AOAC collaborative study. Ten laboratories participated and assayed 12 test portions (6 blind duplicates) containing RMD. The 6 test pairs ranged from 1.5 to 100% RMD. The method consisted of the following steps: (1) The insoluble dietary fiber (IDF) and high MW soluble dietary fiber (HMWSDF) were determined by AOAC 985.29. (2) Ion exchange resins were used to remove salts and proteins contained in the AOAC 985.29 filtrates (including ethanol and acetone). (3) The amount of low MWRMD (LMWRMD) in the filtrates were determined by liquid chromatography. (4) The TDF was calculated by summation of the IDF, HMWSDF, and LMWRMD fractions having nondigestible carbohydrates with a degree of polymerization of 3 and higher. Repeatability standard deviations (RSDr) were 1.33–7.46%, calculated by including outliers, and 1.33–6.10%, calculated by not including outliers. Reproducibility standard deviations (RSDR) were 2.48–9.39%, calculated by including outliers, and 1.79–9.39%, calculated by not including outliers. This method is recommended for adoption as Official First Action.

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

2010 ◽  
Vol 93 (1) ◽  
pp. 221-233 ◽  
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.

scholarly journals Total Dietary Fiber (CODEX Definition) in Foods and Food Ingredients by a Rapid Enzymatic-Gravimetric Method and Liquid Chromatography: Collaborative Study, First Action 2017.16

2019 ◽  
Vol 102 (1) ◽  
pp. 196-207 ◽  
Author(s):  
Barry V McCleary ◽  
N Ames ◽  
J Cox ◽  
S Iilians ◽  
Y Jin ◽  
...  
Keyword(s):  
Dietary Fiber ◽  
Collaborative Study ◽  
Gravimetric Method ◽  
Soluble Dietary Fiber ◽  
Total Dietary Fiber ◽  
Plant Materials ◽  
Food Ingredients ◽  
Insoluble Dietary Fiber ◽  
The Past ◽  
Aoac Method

Abstract A method for measurement of total dietary fiber (TDF) has been validated. This method is applicable to plant materials, foods, and food ingredients as consumed, consistent with the 2009 CODEX definition (ALINORM 09/32/REP), and measures insoluble dietary fiber (IDF) and soluble dietary fiber (SDF), comprising SDF that precipitates in the presence of 78% ethanol (SDFP) and SDF that remains soluble in the presence of 78% ethanol (SDFS). The method is an update of AOAC Method 2009.01 and addresses each of the issues identified by analysts in using that method over the past 8 years. A total of 13 laboratories participated in the study, with all laboratories returning valid assay data for most of the 16 test portions (8 blind duplicates) consisting of samples with a range of content of traditional dietary fibers, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 6.90 to 60.37 g/100 g. TDF was calculated as the sum of IDF plus SDFP measured gravimetrically and SDFS measured by HPLC. The repeatability SD ranged from 0.27 to 0.76 g/100 g, and the reproducibility SD ranged from 0.54 to 3.99 g/100 g. The RSDr ranged from 1.22 to 6.52%, and the RSDR ranged from 2.14 to 10.62%.

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