engleski

Comparative HPLC-DAD study of chlorophylls and carotenoids extracted from Mediterannean herbs by successive extraction

Due to their great diversity, Mediterranean plants possess a wide range of bioactive molecules among which the pigments represent one of the major constituents. Thus, this study examined composition and properties of pigments from several Mediterranean shrubs and subshrubs (Myrtus communis, Pistacia lentiscus, Thymus vulgaris, Salvia officinalis, and Laurus nobilis) collected in the Adriatic coastal area. Pigments were extracted by successive solvent extraction of leaves with hexane, 80%-acetone, and 96%-ethanol and agitation-assisted extraction (AAE), ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) were compared. In the obtained extracts, the content of total pigments and antioxidant capacity were determined spectrophotometrically, while individual chlorophylls and carotenoids were analyzed using HPLC DAD analysis. Pheophytin a, b and b’, followed by chlorophyll a and b, were dominant chlorophyll molecules while lutein and β-carotene were dominant carotenoids. Overall extracted pigments were determined in the range of 73.84 – 127.60 mg 100 g-1 and were the lowest in T. vulgaris with no significant differences between other species, while M. communis extracts contained the most carotenoids. Antioxidant capacity was highest in M. communis and P. lentiscus and showed a moderate positive correlation with carotenoids and chlorophylls levels. Even though AAE and PLE had similar efficacy, preference can be given to the PLE method due to its shorter extraction time and lower solvent consumption. Successive solvent extraction has confirmed differences in the polarity of determined pigments as most of them had medium-level polarity and dissolved in 80%-acetone as a medium polar solvent. Examined plant species certainly expressed their diversity and potential in the application of various functional products.

Chlorophylls ; Carotenoids ; Sucessive extraction ; HPLC-DAD

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