A rapid and effective approach for on-site assessment of total carotenoid content in wolfberry juice during processing

Background: Carotenoid content analysis in wolfberry processed products has mainly focused on the determination of zeaxanthin or zeaxanthin dipalmitate, which cannot indicate the total carotenoid content (TCC) in wolfberries.

Results: We have exploited an effective approach for rapid extraction of carotenoid from wolfberry juice and determined TCC using UV-visible spectrophotometry. Several solvent mixtures, adsorption wavelengths of carotenoid extracts and extraction procedures were investigated. The optimal solvent mixture with broad spectrum polarity was hexane-ethanol-acetone (2:1:1) and optimal wavelength was 456 nm. There was no significant difference of TCC in wolfberry juice between direct extraction and saponification extraction.

Conclusion: The developed method for assessment of TCC has been successfully employed in quality evaluation of wolfberry juice under different processing conditions. This measurement approach has inherent advantages (simplicity, rapidity, effectiveness) that make it appropriate for obtaining on-site information of TCC in wolfberry juice during processing.