UV-Vis Spectroscopy for Quality Assessment of Paprika as per ASTA Method 20.1

Importance of the Topic

Paprika’s red color is a key indicator of quality, authenticity and consumer appeal. UV-Vis spectrophotometry allows rapid, objective quantification of pigment concentration to support grading and regulatory requirements.

Study Objectives and Overview

This application note demonstrates the use of ASTA Method 20.1 for extractable color determination in paprika samples using the Agilent Cary 3500 Multicell UV-Vis system coupled with Cary UV Workstation software. Two commercial paprika samples were evaluated to determine their ASTA color values and assess method reproducibility.

Methodology

Sample preparation involved weighing approximately 90 mg of paprika, extracting pigments in ACS-grade acetone in 100 mL volumetric flasks, and allowing a 16-hour equilibration at room temperature in darkness. Extracts were measured at 460 nm in 10 mm quartz cuvettes. The end-of-sequence analysis tool calculated absorbance and ASTA color values automatically.

Instrumentation

• Agilent Cary 3500 Multicell UV-Vis spectrophotometer (eight-channel multicell module)
• Agilent Cary UV Workstation software for data acquisition, sequence analysis and reporting
• Starna CRM 18294 metal-on-quartz filter reference standard (0.4–0.6 Abs at 465 nm)
• Standard 10 mm quartz cuvettes and ACS-grade acetone

Main Results and Discussion

• The instrument correction factor (If) averaged 1.0036 with RSD ≈0.02%, confirming measurement stability well below the 1% RSD requirement.
• Sample 1 yielded a corrected ASTA color value of ~103, while sample 2 scored ~61, reflecting significant differences in pigment intensity.
• Software features such as end-of-sequence analysis, spectrum comparison and automated report generation streamlined workflow and minimized manual calculations.

Benefits and Practical Applications

• High-throughput multicell design enables simultaneous analysis of multiple samples, improving lab efficiency.
• Automated data processing ensures traceable, reproducible results and reduces the risk of transcription errors.
• Standardized method compliance supports quality control, regulatory audits and commercial spice grading.

Future Trends and Prospects

• Integration with laboratory information management systems (LIMS) for end-to-end data tracking.
• Expansion of the workflow to other spices and food matrices using standardized spectroscopic methods.
• Advanced chemometric and multivariate analysis to enhance spectral interpretation and adulteration detection.
• Development of inline or portable UV-Vis systems for real-time field quality monitoring.

Conclusion

The Agilent Cary 3500 Multicell UV-Vis spectrophotometer combined with Cary UV Workstation software offers a robust, automated solution for paprika color assessment according to ASTA Method 20.1. The approach delivers reliable quantification, high throughput and streamlined reporting, supporting quality assurance in food and beverage testing.

References

• ASTA Method 20.1: Extractable Color in Capsicums and Their Oleoresins, Revised October 2004.