On-line extraction and determination of targeted carotenoids from habanero red (Capsicum Chinese)

Importance of the topic

The profiling of carotenoids in food matrices is crucial for nutritional assessment, quality control and the discovery of bioactive compounds. Carotenoids exhibit antioxidant and provitamin A activity and contribute to food color and health benefits. On-line coupling of supercritical fluid extraction with supercritical fluid chromatography and triple quadrupole mass spectrometry (SFE-SFC-QqQ MS) delivers a rapid, selective and environmentally friendly approach to analyze these compounds in complex samples such as habanero red pepper.

Objectives and study overview

This study aimed to develop an automated on-line SFE-SFC-QqQ MS method to extract and characterize targeted carotenoids from Capsicum chinense. Key goals included optimizing extraction parameters, improving run-to-run precision, enabling batch-type workflows and providing comprehensive profiling of free, mono- and di-ester carotenoids.

Methodology and instrumentation

A grinded habanero sample mixed with absorbent powder was loaded into a 0.2 mL extraction vessel for on-line SFE using supercritical CO2 modified with methanol. Extraction temperatures (40–80 °C), static/dynamic modes and flow rates were optimized. The extract was transferred directly to an SFC system with a fused-core C30 column and CO2/methanol gradient. A Shimadzu Nexera-UC platform, including SFE-30A, SFC-30A modules, dual LC pumps, back pressure regulators, column oven, autosampler and LCMS-8050 QqQ MS with APCI source, performed separation and detection. Data acquisition modes included SCAN, SIM and MRM in both positive and negative APCI.

Main results and discussion

• Extraction yield increased with temperature, reaching an average of 48.6 % at 80 °C; most analytes were depleted after four sequential extractions.
• A total of 21 analytes were identified, comprising free carotenoids (α-/β-carotene, lutein, zeaxanthin), mono-esters and di-esters of xanthophylls such as capsanthin esters.
• Rapid polarity switching in APCI enabled complementary molecular ion and fragment information in a single run.
• SIM and MRM modes provided high sensitivity and selectivity for quantifying key carotenoids including lutein, zeaxanthin and capsanthin.

Benefits and practical applications

This on-line method reduces total analysis time to 18 minutes per sample, minimizes organic solvent use and contamination risk, and ensures excellent precision. It is ideal for routine quality assurance, nutritional profiling and research on carotenoid-rich foods and other complex matrices.

Future trends and applications

• Extension to untargeted metabolomic screening through high-resolution MS coupling.
• High-throughput automation for food, pharmaceutical and nutraceutical industries.
• Application to additional bioactive classes and diverse matrices such as cosmetics.
• Integration with machine learning for pattern recognition and compound discovery.

Conclusion

The developed on-line SFE-SFC-QqQ MS platform offers a fast, accurate and eco-friendly solution for detailed carotenoid analysis in food samples. Its automated workflow and robust performance support advanced applications in analytical chemistry, quality control and nutritional research.

Used instrumentation

Shimadzu Nexera-UC system including SFE-30A extraction module, SFC-30A back pressure regulators, LC-20ADXR and LC-30ADSF pumps, CTO-20AC oven, SIL-30AC autosampler and LCMS-8050 triple quadrupole MS with APCI source.

References

1. Giuffrida D., Dugo P., Torre G., et al. Food Chemistry 140 (2013) 794–802.
2. Rivera S.M., Canela-Garayoa R. Journal of Chromatography A 1224 (2012) 1–10.