2.5. Pigment extraction from tomato fruits
Ground tomato fruit (8 g) was thoroughly mixed with 40 cm3 of ethanol.
The slurry was stirred until the tomato paste material was no longer sticky (about 3 min). Ethanol was removed by vacuum filtration.
The retained tomato residue was mixed with 60 cm3 of a mixture of acetone and petroleum ether (1:1).
The filtrate was transferred to a small separation funnel and mixed with 50 cm3 of saturated NaCl solution. The organic layer was rewashed twice, repeatedly, first with 50 cm3 of 10% potassium carbonate and then with 50 cm3 of water. Finally, approximately 1 g of anhydrous magnesium sulfate was added to dry the organic layer.
After 10–15 min, the solution was vacuum filtered to remove the drying agent (Cvetkovic and Markovic, 2008).