Supercritical CO₂ extraction vs. hexane extraction and cold pressing: Evaluation of fatty acids and unsaponifiable matter in vegetable oils

Vegetable oils are extensively used in the pharmaceutical, cosmetic and food industries. Conventional methods for their production include organic extraction with hexane and cold pressing but are associated with disadvantages, e.g. high solvent consumption and solvent residuals in terms of toxicity, and low yields in terms of economic efficiency. A method that overcomes many of these limitations is supercritical CO₂ extraction.

We selected 7 oils with different fatty acid compositions: pumpkin (Cucurbita pepo), linseed (Linum usitatissimum), linden (Tilia sp.), poppy (Papaver somniferum), apricot (Prunus armeniaca), marigold (Calendula officinalis) and milk thistle (Silybum marianum) seed oils, dominated by oleic, linoleic, linolenic or calendic acid. The main goal of our work was to compare the products of CO₂ and hexane extractions and cold pressing in terms of oil yield, the composition of fatty acids and unsaponifiable compounds, and antioxidative activity.

None of the methods resulted in significant changes in fatty acid composition and none was superior in terms of yield. However, when comparing hexane and CO₂ extraction, the latter gave a higher oil yield in 5 samples. CO₂ extraction was the most efficient in lower-yielding crops. Unsaponifiable matter of pumpkin and poppy seed oils showed the highest and the lowest antioxidative activity, respectively. We found a positive correlation between antioxidative activity and the content of cycloartenol and squalene [1] [2].

We conclude that CO₂ extraction is an efficient and environmentally friendly method for the production of vegetable oils, and will become an important part of vegetable oil production in the future.

 

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• References

• 1 Poljsak N, Kocevar Glava N.. Vegetable butters and oils as therapeutically and cosmetically active ingredients for dermal use: A review of clinical studies. Front Pharmacol 2022; 13: 868461
• 2 Schoss K, Kocevar Glava N, Dolenc Koce J, Anzlovar S.. Supercritical CO₂ Plant Extracts Show Antifungal Activities against Crop-Borne Fungi. Molecules 2022; 27 (03) 1132

Publikationsverlauf

Artikel online veröffentlicht:
16. November 2023