EXTRACTION OF CHLOROPHYLLS AND CAROTENOIDS FROM SPRUCE NEEDLES WITH SUPERCRITICAL CARBON DIOXIDE

Supercritical carbon dioxide, being a non-polar solvent, has proven itself well as an extractant for the extraction of non-polar compounds from plant materials. However, the use of co-solvents that enhance the polar properties of the SO2 in the supercritical state greatly enhances its use for extraction. Wood greens, in particular spruce, contain a large number of useful substances of varying polarity, for which extraction is one of the main extraction methods. Spruce needles were extracted with supercritical carbon dioxide with alcohol additives as co-solvents to extract chlorophylls and carotenoids. The pigment content of the sample obtained by exhaustive Soxhlet extraction with ethanol (isopropanol) was 0.025 mg/g for carotenoids, 0.3 mg/g for chlorophylls. Supercritical pigment extraction was carried out in a Waters MV-10ASFE extractor (USA) at temperatures of 60 °C and 80 °C, varying in pressure from 100 at to 300 at, co-solvent concentration from 0 to 10%, extraction duration from 10 to 60 minutes. Analysis of extracts for carotenoids and chlorophyll was carried out by high-performance liquid chromatography on LC-30 “Nexera” (Shimadzu), Japan. It has been found that supercritical SO2 at maximum process parameters is capable of extracting three times more carotenoids than chlorophylls. The addition of co-solvents has little or no effect on the amount of carotenoids recovered, while the chlorophyll content of the extract can be increased 4–7 times with ethanol and 3–4 times with iso-propanol.