Identification of β-carotene oxidation products produced by bleaching clay using UPLC-ESI-MS/MS

• Published in: Food chemistry 2021-08, Vol.353, p.129455-129455, Article 129455
• Main Authors: Hambly, Andrew J., van Duijneveldt, Jeroen S., Gates, Paul J.
• Format: Article
• Language: English
• Subjects: Acid-activated clay; Oxidation; UPLC-MS; Vegetable oil; β-Carotene
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2021.129455

•Vegetable oil pigment β-carotene is oxidised by acid-activated bleaching clay.•High resolution UPLC-MSn reveals a large mixture of oxidation products.•Chemical standards & MS/MS spectra interpretation identifies several oxidation products.•H218O labelled clay showed adsorbed water to be the source of oxygen.•Provides insight into the removal of carotenoids during vegetable oil bleaching. 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.