Action of chlorophylls on the stability of virgin olive oil

Virgin olive oil was used as substrate to study the influence of chlorophylls on its oxidative stability in light and in darkness. Chlorophylls a and b were added to this substrate, after which oils were stored at 36 ± 2°C for three months under artificial light (1340 lux) or in darkness. The effect of light was greater than that of the additives. The prooxidant action of chlorophylls in the presence of other pigments of the oil was not observed in this assay. During early storage, the rate of peroxide formation was lower in the samples with added chlorophylls, but later it equalled that of the control. In darkness, stability was greater in the samples containing chlorophylls, indicating a slight antioxidant effect, which was more marked for chlorophyll a