Innovative Extraction of Lipophilic Fractions from Chokeberry Pomace
Laura Jūrienė, Petras Rimantas Venskutonis
Department of Food Science and Technology, Kaunas University of Technology, Lithuania
Keywords: chokeberry pomace, supercritical fluid extraction, phytochemical composition.
Abstract:
Black chokeberries, widely used in juices, jams, and wines, generate pomace during processing that is often discarded despite being rich in bioactive compounds. Besides polyphenols, anthocyanins, procyanidins, flavonols, and phenolic acids, this by-product also contains valuable lipophilic substances such as fatty acids, triacylglycerols (TAGs), tocopherols, and phytosterols. The objective of this study was to evaluate the potential for fractionating lipophilic compounds from chokeberry pomace using supercritical fluid extraction with carbon dioxide (SFE-CO₂), applied either alone or with 5% ethanol as co-solvent, and to characterise the yield, antioxidant capacity, and phytochemical composition of the obtained fractions. SFE with pure CO₂ produced a 14% lower yield compared to CO₂ with ethanol. With pure CO₂, most of the extract accumulated in the first separator, whereas ethanol addition shifted yields toward the second separator. Antioxidant activity, measured by the L-ORAC assay, was about two-fold higher in lipophilic extracts from the first separator when ethanol was present, while fractions from the second separator showed similar activity in both cases. The extracts were rich in highly unsaturated TAGs, particularly LLLn (23.26–24.18%), OLnL (20.35–22.10%), LLnLn (13.20–15.10%), and OLL (10.02–12.06%). Four tocopherols and four phytosterols were detected: under pure CO₂, tocopherols were more abundant in the second separator, while phytosterols were slightly higher in the first. Ethanol addition increased the concentration of both in the second separator. In conclusion, modifying the solvent composition and separator conditions during SFE enables the production of lipophilic fractions with distinct profiles, thereby supporting the valorisation of chokeberry pomace as a source of functional bioactives.
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