Quantitative Raman Analysis of Carotenoid Protein Complexes in Aqueous Solution

Area of Science:

• Biochemistry
• Analytical Chemistry
• Spectroscopy

Background:

• Carotenoids are vital fat-soluble pigments with antioxidant and vision benefits.
• Dietary carotenoids like Beta Carotene, Lutein, and Zeaxanthin are crucial for health.
• Understanding their quantification in biological matrices is important for clinical analysis.

Purpose of the Study:

• To explore Raman spectroscopy for differentiating and quantifying Beta Carotene, Lutein, and Zeaxanthin.
• To assess the potential of this technique for analyzing carotenoid-protein complexes in aqueous solutions.
• To evaluate the applicability of Raman spectroscopy for clinical analysis of human serum.

Main Methods:

• Complexing Beta Carotene, Lutein, and Zeaxanthin with bovine serum albumin (BSA).
• Utilizing UV-Vis absorption spectroscopy for linearity confirmation.
• Employing Raman spectroscopy with a 532 nm laser source for optimal spectral acquisition.
• Applying data preprocessing, partial least squares (PLS) modeling, and Principal Components Analysis (PCA).

Main Results:

• A PLS model achieved high accuracy (R²=0.9995, RMSEP=0.0032 mg/mL) for Beta Carotene quantification.
• PCA successfully differentiated the spectral signatures of the three carotenoids.
• Least squares fitting demonstrated accurate quantification of carotenoid admixtures in complexes.

Conclusions:

• Raman spectroscopy, coupled with chemometrics, offers a sensitive and specific method for carotenoid analysis.
• The technique shows significant potential for quantifying carotenoid content in human serum.
• This approach could aid in identifying differential carotenoid contributions for clinical diagnostics.