New method for carotenoid extraction and analysis by HPLC-DAD-MS/MS in freeze-dried citrus and mango pulps

Abstract

Carotenoid analysis in citrus is still a challenge due to their complex carotenoid profile and matrix acidity, which can promote isomerization and epoxide-furanoid rearrangements of these compounds. A new method for carotenoid extraction from freeze-dried citrus was developed. Extraction was carried out by magnetic stirring using ethyl acetate and methanol as solvents and Na2CO3 to neutralize organic acids. Liquid-liquid partition was achieved by centrifugation. Carotenoid quantification was accomplished by both UV-Vis and high-performance liquid chromatography-diode array detection (HPLC-DAD). Method repeatability (2.9 to 8.5%) and recovery (82 to 88%) were similar to reported values for procedures including all the carotenoid analysis steps. In ‘Valencia’ orange pulp, xanthophylls accounted for 98% of the total carotenoid content and the predominant carotenoids were (9Z)-violaxanthin, (all-E)-lutein and (9Z)-antheraxanthin. This method was further applied for carotenoid analysis in freeze-dried ‘Tommy Atkins’ mango pulp. The developed method is precise, accurate, fast and able to maintain epoxy-carotenoids stability during analysis.