Carotenoid Measurement in Infant Formula Using a Validated Analytical Method

Background: Studying the effects of dietary carotenoids in infants is complicated due to an absence of information on carotenoid concentrations in formula and due to naturally variable amounts found in human milk. Therefore, human milk and formula carotenoids must be quantified using a valid analytical method. Objective: To accurately and reliably measure carotenoids in commercial infant formula using a previously validated carotenoid extraction method. Methods: Beta-carotene, lutein, and lycopene were extracted according to a modified version of Schimpf, et al. (2018. J AOAC Intl, 101:1249-1252) and quantified by high-performance liquid chromatography-photodiode array detection. Accuracy and reliability were determined for a standardized infant formula reference material from the National Institute of Standards and Technology (NIST) (N=5 trials). Carotenoids were measured by the analysis of six commercial formulae (N=5 trials). Results: Carotenoids could be extracted for accurate and reliable quantitation of standardized NIST formula, with average relative standard deviations of 11%, 3%, and 14% for beta-carotene, lutein, and lycopene, respectively, and measured carotenoid concentration ranges overlapped with certified ranges. Lutein was most abundant across 5 brands of Manufacturer A’s formula, followed by lycopene and beta-carotene. Only beta-carotene was detected in manufacturer B’s formula. Conclusions: The method reliably and accurately extracts carotenoids from standardized infant formula reference material. Carotenoids in the majority of commercial formulae correspond with manufacturer-provided ingredients lists. This project was completed with contributions from Noor Hason and Nancy E. Moran from Baylor College of Medicine.