Evaluation of Oxidation Stability of Refined Mineral Oil Enriched with Carotenoids from Carrot Using Supercritical Carbon Dioxide Extraction

Refined mineral oil, intended for various technical applications, was enriched with carotenoids by supercritical carbon dioxide extraction using the oil itself as cosolvent. It was envisioned that the carotenoids could function as renewable oil additives, adding chemical functionality to the end product such as enhanced resistance to oxidation. In order to investigate such possible antioxidant activity, a testing protocol was developed in which oil samples were thermally aged in the presence of a controlled amount of oxygen, and the time-dependent hydroperoxide and keto functionality concentration was monitored. An indication of antioxidant activity was indeed found, and further experiments were undertaken in order to investigate whether this was caused by the main carotenoid found in carrots, beta-carotene. This was not found to be the case, and other possible explanations for the observed oxidative behavior, still to be investigated, are discussed.