Total carotenoid amount in crude twig extracts may be overestimated due to interference by high contents of co-extracted phenolics

Total carotenoids assessed spectrophotometrically in crude extracts may be considerably overestimated when high contents of phenolic compounds are co-extracted. In this case, the absorbance tails of phenolics extend well into the blue part of the spectrum, interfering with carotenoid estimation. Extracts of phenolic-rich organs, with a low ratio of photosynthetic to heterotrophic and/or supportive cells (for example, stems or twigs) are vulnerable to such pitfalls and may need chromatographic separation of carotenoids.