3. FOOD ChEMISTRy & bIOTEChNOLOGy 3.1. Lectures

Chem. Listy, 102, s265–s1311 (2008) Food Chemistry & Biotechnology
tested in the first stage. However, due to relatively high limits
of detection, the composition of mobile phase was modified
using acetic acid to enhance MS ionisation.
Performance characteristics. The quantification was
carried out using the standard addition method. The crude
flaxseed extracts were spiked with analytes to increase the
analytical signal by a factor of 1.5 to 3.
The limits of detection (LOD) were determined by five
repetitive analysis of standard solutions, the found values
were for SECO 0.020 mg kg –1 and for MAT 0.025 mg kg –1 .
The repeatability was determined by six times analysis
of flaxseed extracts and was expressed as relative standard
deviation (RSD, %), the value for MAT was 3.2 % and for
SECO 4.7 %.
Table I
Average levels of SECO and MAT in different cultivars of
flaxseed
Cultivar MAT [mg kg –1 ] SECO [mg kg –1 ]
AGT 13 1157
Alaska 22 2317
Astral 14 1955
Atalante 14 1317
Bajkal 13 1172
Baladin 11 1197
Flanders 14 1193
Lola 12 1150
Oural 11 716
Recital 12 1030
Venica 16 682
s697
Concentration of lignans in flaxseeds. The mean levels
of lignans are shown in Table I. Their amount in various flaxseed
samples ranged for SECO from 219 (Venica) to 2610
(Alaska) mg kg –1 , and for MAT from 5 (AGT 984) to 22
(Alaska) mg kg –1 with average levels 1031 mg kg –1 of SECO
and 13 mg kg –1 of MAT. The levels of SECO were significatly
lower in fibre flax cultivar Venica (220–860 mg kg –1 )
compared to linseed oil cultivars (280–2600 mg kg –1 ). The
differences in MAT content were comparable in both types
of linseeds.
Conclusions
LC-MS/MS method for determination of plant lignans,
SECO and MAT, in flaxseed has been developed and validated.
Flaxseeds were shown to be a rich dietary source of
lignans. The dominating phytoestrogens representing this
biologically active compounds were SECO and MAT. The
highest lignans content was in cultivar Alaska.
This study was carried out within the projects NPVII
2B06087 and MSM 6046137305 supported by the Ministry of
Education, Youth and Sports of the Czech Republic.
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