Application of a High‐Performance Liquid Chromatography Method for the Evaluation of Non‐Provitamin A Carotenoids

Abstract

Biofortification of maize with provitamin A carotenoids is an emerging intervention for providing vitamin A to people where maize is a staple crop. Analyzing the effectiveness of biofortified maize adoption will be important in the coming years. We propose that serum carotenoid profiles will be ideal for this endeavor. The C30 HPLC column was developed specifically for carotenoid separations because the longer alkyl chains provide better separation of carotenoids and their respected isomers. Most types of maize that have been released also have enhanced concentrations of the xanthophyll carotenoids lutein and zeaxanthin. Due to the chemical similarity of lutein and zeaxanthin, the C30 column is ideal for analysis because it is capable of maintaining separation of these two non‐provitamin A carotenoids. A potential drawback of the C30 column is longer analytical time specifically for lycopene. When monitoring study subject low carotenoid diets during a human maize feeding trial, we propose that lycopene can be used as a qualitative measure of compliance due to the abundance of the carotenoid in the typical western diet and the absence of lycopene in maize. Here we show the adaptation of an established HPLC method (Howe & Tanumihardjo, 2006) to include the quantification of lycopene and its respective isomers with a run time of 52 minutes, including equilibration, while maintaining the separation of lutein and zeaxanthin. Thus, serum carotenoids analysis could be useful for both measuring the adoption of maize and compliance in controlled feeding studies.Support or Funding InformationSupported by USDA Hatch WIS01804, Global Health Funds at UW‐Madison, and Harvest Plus breeding contract 5204.