AOAC RI ERP E-Book - DS DF

OMAMAN-38 A: Collaborative Study Manuscript Expert Review Panel Use Only September, 2017

(f) Determine peak areas of SDFS (PA-SDFS) and internal standard (PA-IS) in chromatograms of sample extracts. Inject sample extracts [ H (c)] on LC. Record areas of all

peaks of DP greater than the DP2/DP3 demarcation point as PA-SDFS. Record the peak area of internal standard as PA-IS.

I. Calculations for HMWDF (IDF + SDFP) Blank (B, mg) determination .

B = [(BR 1 + BR 2 )]/2 – P B – P A

Where: BR 1 and BR 2 = residue mass, in milligrams, for duplicate blank determinations, respectively, and P B and P A = mass, in milligrams, of protein and ash, respectively, determined on first and second blank residues.

HMWDF (mg/100 g) = [(R 1 + R 2 )/2 – P B – P A – B]/(M 1 + M 2 )/2] x 100

Where: R 1 = residue mass 1 from M 1 in milligrams; R 2 = residue mass 2 from M 2 in milligrams; M 1 = test portion mass 1 in grams; M 2 = test portion mass 2 in grams; P A = ash mass in milligrams from R 1 ; P B = protein mass in milligrams from R 2 .

J. Calculations for SDFS

Internal Standard Method SDFS(mg/100 g) = Rf ×Wt-IS × (PA-SDFS)]/(PA-IS) x 100/M AOAC Research Institute ERP Use Only where Rf = the response factor; Wt-IS = milligrams of internal standard contained in 1 mL of internal standard solution (100 mg/mL) pipetted into sample before filtration; PA-SDFS = the peak area of the SDFS; PA-IS = the peak area of the internal standard; M = the test portion mass M 1 or M 2 of the sample whose filtrate was concentrated and analyzed by LC.

L. Calculation of Total Dietary Fiber

Total Dietary Fiber (%) = (IDF + HMWSDF + LMWSDF)/1000

Method updated 2008--08-10 This copy printed 22 August 2017

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