[Comparison of lutein, zeaxanthin and β-carotene level in raw and cooked foods consumed in Beijing]

Abstract

Objective: To measure lutein, zeaxanthin and β-carotene level in foods commonly consumed in Beijing, and compare the content difference between raw and cooked food.

Methods: Forty-six commonly consumed foods of 8 classes were collected in Haidian district of Beijing from September to October in 2009. A high performance liquid chromatography method was used to determine the content of lutein, zeaxanthin and β-carotene in both raw and cooked samples.

Results: Lutein was abundant in cucurbitaceous and solanaceous, allium and nuts, especially in Chinese chive (18 226.9 µg/100 g) and pumpkin (13 265.2 µg/100 g). Major sources of zeaxanthin included round pumpkin, green garlic shoot, corn and eggs, whose level of zeaxanthin were 444.6, 283.5, 279.7, 118.6 - 377.9 µg/100 g, respectively. Zeaxanthin level of those cooked foods changed to 483.9, 239.3, 279.1, 149.5 - 594.7 µg/100 g, respectively. The zeaxanthin level of cooked Chinese chive reached 1081.2 µg/100 g, while we did not detect any zeaxanthin in raw Chinese chive. β-carotene was present in a wide variety of vegetables and fruits. Carrot (17 234.3 µg/100 g) was a good source of β-carotene, while its level in cooked carrot was 17 013.5 µg/100 g.

Conclusion: Consuming the proper kinds of foods and changing the method of food processing were beneficial to increase the intake of lutein, zeaxanthin and β-carotene.