Fruit Juice Carotenol Fatty Acid Esters and Carotenoids As Identified by Matrix-Assisted Laser Desorption Ionization (MALDI) Mass Spectrometry

Abstract

Gradient and isocratic HPLC separated as many as 38 carotenoid components in extracts from fruit juices. Several oxygenated carotenoids (xanthophylls), hydrocarbon carotenoids, and carotenol mono- and bis-fatty acid esters were identified. Structural elucidation was based on UV/vis spectroscopy, matrix-assisted laser desorption ionization (MALDI) post-source-decay (PSD) mass spectrometry, and comparison with synthetic reference compounds. Straight-chain fatty acid esters (caprate, laurate, myristate, palmitoleate, palmitate, oleate) of β-cryptoxanthin were identified as major carotenoid constituents in tangerine juice concentrate. Fatty acid components were identified by MALDI PSD fragment ion analysis. The xanthophylls violaxanthin, luteoxanthin, neoxanthin, taraxanthin, antheraxanthin, mutatoxanthin, β-cryptoxanthin-5,6:5‘,6‘-diepoxide, lutein, zeaxanthin, α-cryptoxanthin, and β-cryptoxanthin were present in the extracts of saponified tangerine concentrate. The chromatographic profiles of orange juice concentrate showed marked differences from those of tangerine concentrate. In the saponified extract, the oxygenated carotenoid zeaxanthin predominated over β-cryptoxanthin. Keywords: Carotenoids; carotenol esters; carotenoid analysis; mass spectrometry; matrix-assisted laser desorption ionization

Effect of Net Shading Technology and Harvest Times on Yield and Fruit Quality of Sweet Pepper

“…Mono-and di-esters of red and yellow xanthophylls were identified according to their spectral characteristics before and after alkaline hydrolysis (saponification) using thin-layer chromatographic (TLC) method (Vinkler and Kiszel-Richter, 1972). Additionally, chromatographic behavior and spectral characteristics of fatty acid esters were compared with those stated by Wingerath et al, (1996) and Giuffrida et al, (2013) who used similar chromatographic procedure and identified the carotenoid profile using mass spectroscopic and photo diode-array detection in LC-MS systems. The yellow-colored compounds were quantified as β-carotene equivalent while red colored ones were quantified as capsanthin equivalent.…”

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“…The increase of a conjugation extension is a relevant factor for electron loss and radical stability, and produces spectra complexes from sequential in-source homolytic cleavages, as observed in the MALDI source [4,23,[141][142][143]. The fragmentation patterns of carotenoids and xanthophylls were proposed based on MALDI-PDS data [23,136]. .…”

“…. Other diagnostic carotenoid fragment ions have been described in detail and are useful for elucidating their chemical structures [23,136]. The O-glycosylated isoflavones from soy [Glycine max L. (Fabaceae)] showed fragments with structural importance by PSD, including the main fragment that occurs through the loss of sugars, which is similar to ESI.…”

Analysis of Cyclic and Acyclic Analogs of Retinol, Retinoic Acid, and Retinal by Laser Desorption Ionization-, Matrix-Assisted Laser Desorption Ionization–Mass Spectrometry, and UV/Vis Spectroscopy

“…The natural vitamin A derivatives of retinyl esters have been investigated successfully by employing laser desorption ionization-mass spectrometry (LDI-MS) (25), and the carotenoids by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) (26,27). In the present investigation we report the first application of LDI-and MALDI-mass spectrometry for the analysis of cyclic and acyclic retinoids.…”