The removal of plant pigments such as β-carotene is an aspect of vegetable oil processing often desired by the food and pharmaceutical industries. Adsorption of β-carotene to acid-activated clay (AAC) is a well-established method for purification. Despite this, the removal mechanism of β-carotene is not well understood. UPLC-MS/MS analysis of surface compounds extracted from β-carotene-AAC (BC-AAC) complexes show that AAC acts as an oxidiser. Oxidation products detected included canthaxanthin and 3',4'-didehydro-β-caroten-4-one. AAC had surface water exchanged with an 18O labelled water and was then exposed to β-carotene. Carotenoids labelled with 18O were produced from this reaction, suggesting surface water is necessary for β-carotene removal.
Bibliographical noteFunding Information:
The authors thank Dr Christopher Arthur who assisted in development of the UPLC method. AH was funded by the EPSRC (grant: EP/N509619/1).
© 2021 The Author(s)
- Vegetable oil
- Acid-activated clay