IRON-INDUCED ASTAXANTHIN ACCUMULATION IN HAEMATOCOCCUS PLUVIALIS AND ANTIOXIDANT ACTIVITY OF ASTAXANTHIN-ENRICHED EXTRA-VIRGIN OLIVE OIL DURING THERMAL STORAGE

Abstract

Lipid oxidation affects the sensory quality, nutritional value, and storage stability of edible oils. This study evaluated the effects of chemical stressors on astaxanthin accumulation in Haematococcus pluvialis and the antioxidant activity of astaxanthin-containing extracts incorporated into extra-virgin olive oil (EVOO). Cultures of H. pluvialis NIVA-CHL 49 were exposed to hydrogen peroxide, iron(III) citrate, or EDTA–Fe, and astaxanthin was quantified by high-performance thin-layer chromatography. Iron(III) citrate produced the strongest response, increasing astaxanthin to 19.8 ± 0.7 mg g⁻¹ DW versus 10.2 ± 0.4 mg g⁻¹ DW in the control, a 1.94-fold increase (p < 0.001). Astaxanthin-containing extracts were added to EVOO, heated at 120 °C for 90 min, and stored for 28 days. At the highest oleoresin concentration, DPPH scavenging activity decreased from 88 ± 4% to 68 ± 3%, compared with 45 ± 3% to 32 ± 2% in controls. Oxidation measurements are needed to confirm improved oxidative stability.