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Composition of tomatoes and tomato products in antioxidants (WG1) page 80
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Higher proportions of solvents resulted in a 19% reduction of lycopene extraction
(Taungbodhitham et al. 1998).
Extractions of vitamin E and carotenoids in plasma were shown to be efficient (93-
100%) after only one extraction (Table 27) (Aebisher et al. 1999). A second extraction leads
to a total extraction of all tested compounds. Similar results have been reported for carotenoid
extraction from tomato juice, carrots, and spinach (Taungbodhitham et al. 1998). In contrast,
Zaman et al. (1993) found that in contrast to vitamins A and E, β-carotene and lycopene from
plasma were only extracted around 80% after a single extraction and they extracted a second
time to achieve a yield of 100%. Moreover, Aebischer et al. (1999) reported that mixing the
plasma/water/ethanol/n-hexane emulsion on a vortex was not sufficient to extract all the
vitamin A and E and carotenoids quantitatively and they suggested to horizontaly mix 4 ml
tubes in order to have at least a void volume of 2 ml.
Table 27. Effect of the number of extraction procedure on the vitamin A and E,
and carotenoid recovery.
Extraction 1 Extraction 2 Extraction 3
Lycopene 97.2 2.8 0
all-trans β-Carotene 97.2 2.8 0
cis-β-Carotene 100 0 0
α−Tocopherol 95.7 4.3 0
To assess the extraction efficiency of the procedure the same plasma has been extracted three times with nhexane.
(Adapted from Aebisher et al. 1999)
When chlorophylls or high lipid levels were present in the biological material it would
be necessary to use alcaline treatment (saponification). The objective of this procedure is to
remove chlorophylls and to hydolyze triglycerides in water-soluble fatty acid salts. However
incubation with 30% methanolic KOH for 3 h at room temperature under nitrogen resulted in