Microwave-assisted hydrolysis of lutein and zeaxanthin esters in marigold (Tagetes erecta L.).

Saponification of lutein and zeaxanthin was performed by microwave-assisted hydrolysis (MAH) and analysed by ultra performance liquid chromatography. The optimal condition of MAH was studied, and the degradation or isomerization of lutein and zeaxanthin were estimated under MAH. The concentrations of lutein and zeaxanthin in 20 marigold samples were assessed by saponification using traditional heater and MAH, the regression coefficient of lutein obtained by two methods was 0.9688 and that of zeaxanthin was 0.9527. The limit of detection for lutein and zeaxanthin was 0.05 and 0.1 μg/ml, respectively, and the limit of quantification for lutein and zeaxanthin was 0.05 mg/100 g and 0.1 mg/100 g, respectively.