Comparison of quantitative carotenoid analysis using UV-Vis spectrophotometry and high-performance liquid chromatography

Resumo

The quantification of β-carotene in agricultural by-products is crucial for their valorization. However, commonly used analytical methods, such as UV–Vis spectrophotometry and high-performance liquid chromatography (HPLC), present critical differences in specificity and cost. This study compared β-carotene quantification using both methods, employing ethanol and hexane as extraction solvents, to determine β-carotene in peels from four mango varieties (Kent, Edward, Haden, and Criollo), following a 2×2×4 factorial design. Proximate analysis revealed significant differences in composition among the varieties. The results demonstrated a significant effect of the triple interaction (method × solvent × variety), indicating that all factors must be considered when selecting a β-carotene quantification protocol. Spectrophotometry systematically overestimated β-carotene content (up to 60% higher with ethanol) due to interference from other pigments. In contrast, HPLC provided specific quantification, revealing that hexane was significantly more efficient than ethanol for extraction. The Kent variety showed the highest β-carotene content. It is concluded that the HPLC–hexane combination is the optimal protocol for accurate quantification, whereas spectrophotometry provides only a useful screening estimate that should be interpreted with caution. The use of HPLC is recommended for studies requiring high accuracy, as well as for the validation of rapid methods against this standard for each new matrix.