Carotenoid Profiling of Orange-Coloured Capsicums: In Search of High-Zeaxanthin Varieties for Eye Health

Age-related macular degeneration (AMD) is the leading cause of blindness in developed countries, such as Australia. Lutein and zeaxanthin are the only two carotenoids found in the macular region of the eye. Studies have shown that an intake of 10 mg and 2 mg per day of lutein and zeaxanthin, respectively, can reduce the rate of progression of AMD. The supply of these carotenoids can only be met through dietary sources or supplements, as these compounds cannot be synthesised by humans. Although lutein is relatively abundant in dietary sources, zeaxanthin has limited sources. In this study, eight orange and three red capsicum varieties were analysed for their carotenoid profiles by UHPLC-DAD-APCI-MS. It was observed that the principal carotenoid for seven of the orange varieties was zeaxanthin, and capsanthin for the three red varieties. One orange variety, which had a darker orange hue, had capsanthin and violaxanthin as its principal carotenoids instead of zeaxanthin. Zeaxanthin concentration (the principal carotenoid) in the seven orange varieties varied from 2.6 ± 0.5 mg/100 g to 25.27 ± 9.4 mg/100 FW, suggesting that as little as 7 g of the high-zeaxanthin line could meet the recommended daily dietary intake of 2 mg/person/day.