A chemical study of b-carotene oxidation by ozone in an organic model system and the identification of the resulting products

Abstract

Carotenoids are present in many foods. Due to their polyenic chains, they undergo oxidation reactions which may give several compounds. Ozone, a powerful antimicrobial agent, is applied in the food industry due to its high reactivity and penetrability. This work presents a chemical study of the degradation of b-carotene in solutions, under the influence of ozone. The experiments were carried out at ozone concentrations ranging from 0.8 to 2.5 ppm and the b-carotene solutions were sampled and analysed from zero to seven hours of reaction. The oxidation products were collected in C18 cartridges coated with dinitrophenylhydrazine and the hydrazones formed were analysed by LC-MS. The oxidation reaction was found to follow a zero order kinetic model and the b-carotene decay ranged between 17.2% and 99.8%. Fourteen oxidation products were tentatively identified, amongst them eight which had not been cited yet in the literature as oxidation products of b-carotene.