Fiber, Total, Soluble, Insoluble (CODEX Definition)

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Price of the test:

$455 per analysis

Acceptable Matrices:

At this time believed to be acceptable for all foods and food products

Unacceptable Matrices:

Some matrices may be identified as incompatible with this method as the method is utilized more extensively. To date, no unacceptable matrices have been identified

Limit of Detection:

Total Dietary Fiber - 0.1%
Insoluble Dietary Fiber – 0.1%
Soluble Dietary Fiber-0.1%

Sample Size Requirements:

40 grams


Standard Gravimetric Analytical Chemistry Equipment and HPLC

Reportable Units:

Percent by weight of sample as received

Turn Around Time:

15 Business Days - RUSH is available (7 Business Days) please call to ensure timing

Is Rush Available?


Method Reference:

AOAC 2011.25

Method Description:

Samples (defatted if necessary) are digested with a mammalian alpha-amylase and an amyloglucosidase for 16 hours at 37oC to simulate the human digestive system. Following digestion, the sample is heated to 95oC to denature all enzymes and proteins present and then digested at 60oC with protease. Insoluble digestion resistant material (dietary fiber) is filtered away and the amount of Insoluble Dietary Fiber (IDF) is determined gravimetrically with protein and ash content subtracted (note: protein and ash are determined on the residue). The dietary fiber remaining in solution following the filtration is precipitated with ethanol and is collected in a second filtration step. The amount of dietary fiber collected in the filter is determined gravimetrically with protein and ash subtracted as above and is recorded as the Gravimetric Soluble Dietary Fiber (G-SDF). The filtrate containing the soluble dietary fiber not precipitated by the ethanol is concentrated and analyzed by High Performance Liquid Chromatography (HPLC) to determine the total HPLC-Soluble Dietary Fiber (HPLC-SDF) with a degree of polymerization (DP) greater than or equal to 3 (DP³3). The total Soluble Dietary Fiber is calculated as the sum of the Gravimetric-Soluble Dietary Fiber and the HPLC-Soluble Dietary Fiber (SDF = G-SDF + HPLC-SDF). Total dietary fiber is calculated as the sum of the Insoluble Dietary Fiber and the Soluble Dietary Fiber (TDF = IDF + SDF).

Information Required by Submitter:

Please supply expected estimates. Indicate matrix type and indicate high fat (>5%) and high protein (>20%) samples. Indicate whether the sample contains fructans (inulin or fructooligosaccharides (FOS)), or psyllium, flax and gum (i.e. guar gum).

Additional Information:

Measures dietary fiber including resistant starch and non-digestible oligosaccharides of DP >3. Dietary Fiber is the portion of the carbohydrates which is not digested in the human gut. It is composed of both soluble and insoluble components. These methods are applicable to all food products; however samples containing psyllium or fructans should be submitted under specific test codes. High-fat (>5%) and high-protein (>20%, depending on matrix) samples require special handling.