AOAC RI ERP E-Book - DS DF

OMAMAN-38 B: Collaborative Study Protocol 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 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.

IDF + SDFP = (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 from R 2 .

= ash mass in milligrams from R 1

; P B

= protein mass in milligrams

J. Calculations for SDFS

SDFS (mg/100 g) = Rf × Wt-IS × (PA-SDFS)] / (PA-IS) x 100/M 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, M1 or M2 of the sample whose filtrate was concentrated and analyzed by LC. AOAC Research Institute ERP Use Only

K. Calculation of Total Dietary Fiber

Total Dietary Fiber (%) = [(IDF + SDFP) + SDFS)]/1000

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