Stability of zeaxanthin/lutein in yolk oil obtained from microalgae-supplemented egg under various storage conditions

Zeaxanthin (Zx) and Lutein (Lut) are yellow-orange carotenoids that are accumulated in the macular region. Dunaliella species are emerging bio-resources for the production of carotenoid pigments. This research demonstrated the potential of D. tertiolecta mp3 mutant to enrich eggs with Zx and Lut and assessed their stability in yolk oil (YO). Laying hens aged 57-week were supplemented with 2-32 g/kg of D. tertiolecta mp3 mutant powder in their diet. Feeding the powder at 0.8-1.6% efficiently increased Zx and Lut contents more than twice and intensified the yolk color as compared to the control group. Enriched YO contained 0.471 mg/g of Zx and 0.640 mg/g of Lut, 315 mg/g of phospholipid and 11.2 mg/g of cholesterol. Subsequently, the effects of temperature (4, 25, 37 and 55 degrees C), light (884 lux and dark), and atmosphere (ambient air and nitrogen) on the degradation of Zx and Lut were evaluated. As a result, Zx and Lut in YO were well preserved below 25 degrees C and in dark condition regardless of the presence of air. Consequently, the knowledge of Zx and Lut enrichment and degradation kinetics in YO provides valuable information to the nutraceutical and pharmaceutical industries.