Efficient HPLC Separation on a Core-C30 Column with MS2 Characterization of Isomers, Derivatives and Unusual Carotenoids from Tomato Products

Abstract

An efficient and rapid liquid chromatographic method was developed for the separation of carotenoids and their geometrical isomers in tomato products using a core C30 column of 2.6 μm particles with gradient elution of tert-butyl-methyl-ether in 2% water in methanol. Excellent separation of the major carotenoids such as lycopene, β-carotene and lutein as well as their geometrical isomers and oxygen-containing derivatives with resolution factors ranging between 0.78 and 4.0 and selectivity of 1.01–1.63 was achieved. Validation of the developed method met the acceptance criteria concerning linearity, recovery, precision and limit of detection and quantification. Calibrations were linear with correlation coefficient (R2) values between 0.9966 and 0.9999. The limit of detection and quantification values were found to be 0.008 and 0.017 and 0.029 and 0.056 μg/mL, respectively. Recovery of 94.3–99.9%, intraday precision of 1.81–4.45% and interday precision of 3.13–6.86% were obtained. The hyphenation of liquid chromatography with diode-array and mass spectrometry was helpful in the identification of the separated carotenoids particularly the unusual di-hydroxy cyclolycopene adduct and di-methoxy lycopene determined for the first time in tomato products. Commercially available kinds of tomato juice and ketchup were evaluated based on their carotenoid content.

Prediction of Soluble Solids and Lycopene Content of Processing Tomato Cultivars by Vis-NIR Spectroscopy

“…Carotenoids were detected between 190 and 700 nm. Separation of carotenoids was performed on a core C-30, 150 × 4.6 mm, 2.6 μm (Thermo Scientific, Waltham, MA, United States) column with a gradient elution of (A) tert-butyl-methyl ether in (B) 2% water in methanol ( 48 ). The gradient started with 3% A in B, changed to 35% A in B in 20 min, steady isocratic for 5 min, and finally turned to 3% A in B in 5 min.…”

Terpenoid natural products exert neuroprotection via the PI3K/Akt pathway

“… Huang et al (2019) found that lycopene reversed the neurotoxicity induced by tert-butyl hydroperoxide (t-BHP) in an in vitro AD model and elucidated that its neuroprotective mechanism involved the PI3K/Akt pathway. Recently, researchers have developed a rapid and efficient HPLC-DAD-MS2 method to isolate and characterize some carotenoids and their geometrical isomers from tomato products, including some derivatives of lycopene first discovered such as di-hydroxy cyclolycopene adduct and di-methoxy lycopene ( Daood et al, 2022 ).…”