Xanthophyll content of selected vegetables commonly consumed in the Philippines and the effect of boiling

The purpose of this study was to quantify xanthophylls in selected vegetables commonly consumed in the Philippines and to investigate the effect of boiling on their availability. Thirteen vegetables were grouped into green-leafy and non-leafy. Results showed that fresh malunggay contains the highest amount of lutein (167.1±6.1 μg/g), neoxanthin (48.66±2.31 μg/g), and violaxanthin (37.86±1.76 μg/g) while mais has the highest zeaxanthin (269.1±11.8 μg/g). Statistically, there is no significant difference (p>0.1) in xanthophyll content between fresh leafy and non-leafy samples. However, 15-min boiling (100 °C) changed this, resulting in a significant difference (p<0.1) in xanthophyll content between the two groups. Boiling increased the availability of lutein and neoxanthin, while an opposite effect was observed for zeaxanthin and violaxanthin. Results also showed that consuming 20 g of cooked malunggay (Moringa oleifera) can provide 100% the recommended level of lutein (10 mg) for eye health, while 8 g of cooked mais (Zea mays) a day can provide a high enough level (2 mg) of zeaxanthin.