2.7. Total carotenoid content determination
Total carotenoid content (TCC) was determined using a spectrophotometer
(Helios c, Thermo Electron Corporation, USA)
device according to the PN-EN 12136:2000 [34]. Chemicals and
solvents used in this assay were analytical grade and were
acquired from POCH (Gliwice, Poland). To precipitate carotenoids,
approximately 1.5 g of the sample (in the case of dried sample it
was used an equivalent mass of the solid content corresponding
to 1.5 g of raw material) was treated with Carrez I and II solutions.
Afterwards, the extraction was carried out using acetone and petroleum
ether. The absorbance value of the ether extract was measured
at 450 nm. The total carotenoid content (TCC) (mg/100 g)
was calculated according to the following formula