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Memo
Monique Steegmans
16001n-MSS-MSS-SLV FOS01 AOAC997.08 Beneo-Orafti, 1 Febr 2016, page 6/18
2.2.5. Calculation:
For each standard solution, the response factor of each compound Fructose, Glucose and
sucrose is calculated as follows:
R = A x m°
m x A°
R = response factor of the compound
m = mass of the compound in mg/50 cm 3
A = peak area of the compound
m° = mass of IS in mg/50 cm 3
A° = peak area IS
For each compound a calibration curve of the type, y=ax, will be obtained. With this curve all the
concentrations of the compounds present in the sample can be calculated. (r
2
= min 0.995)
See annex 2.
Formula:
w = m° x A x 100
a A° W
w = mass fraction of the compound in mg/100 g sample
A = peak area of the compound
m° = mass of IS in mg/50 cm 3
A° = peak area IS
m = mass of sample in g/50 cm 3
The content of fructose, glucose and sucrose before and after incubation with inulinase for
each sample is calculated. Example of chromatograms, see annex 3.
2.2.6. Calculation of the fructan content:
Fi=Ft-Ff-(S/1,9)
Fi = is the fructose originating from the fructan (inulin of oligofructose)
Ft = the total amount of fructose after incubation with inulinase
Ff is the free content of fructose in g/100 g sample in the initial test portion
S = amount of sucrose in g/100g sample in the initial test portion
The glucose is calculated Gi = (Fi/DP-1)
Gi = the amount of glucose originating from the fructan
Fos-01 (February 2016)
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