Quality Assessment of Saffron by UV‑Vis Spectroscopy in Accordance with ISO 3632

Importance of the Topic

Saffron is the world’s most valuable spice, with its market price tied to its color, aroma, and purity. Its high value and limited availability make it susceptible to adulteration, mislabeling, and quality degradation, posing risks to consumer health and confidence. Reliable and rapid quality assessment methods are essential to ensure product authenticity and to maintain standards across the supply chain.

Goals and Study Overview

This study demonstrates the application of UV-Vis spectroscopy in accordance with ISO 3632-1:2025 and ISO 3632-2:2010 to grade commercial saffron samples. Using an Agilent Cary 3500 UV-Vis spectrophotometer coupled with Cary UV Workstation software, the study aims to quantify the key quality markers—crocin, picrocrocin, and safranal—and assign a commercial grade to the sample.

Methodology and Instrumentation

• Determination of Moisture and Volatile Matter: 2.5 g of saffron filaments were dried at 100 °C for 16 h, yielding a moisture and volatile content (wMV) of 6.43 %.
• Sample Extraction: 0.5 g of crushed saffron was stirred in 900 mL of water for 1 h, diluted, filtered through a 0.45 μm membrane, and prepared in a 10 mm quartz cuvette.
• Spectral Analysis: UV-Vis spectra were recorded from 200 to 700 nm, with absorbance measured at 257 nm (picrocrocin), 330 nm (safranal), and 440 nm (crocin).
• Calculations: Specific absorbance values were corrected for moisture content and sample mass, then converted to strength values according to ISO formulas.

Instrumentation Used

• Agilent Cary 3500 Multicell UV-Vis Spectrophotometer with xenon flash lamp (no warm-up time) and eight-cell configuration.
• Agilent Cary UV Workstation software for automated spectral acquisition, data processing, and ISO-compliant calculations.

Main Results and Discussion

• The moisture content of 6.43 % classified the sample within Extra Class (EC) per ISO 3632-1.
• Measured absorbance values were 0.5156 at 257 nm, 0.2035 at 330 nm, and 1.3351 at 440 nm.
• Calculated strength values: picrocrocin 103.38, safranal 40.81, and crocin 267.70—each exceeding EC minimum requirements.
• Automated workflows within Cary UV Workstation reduced manual errors and provided rapid, traceable classification results.

Benefits and Practical Applications

• Standardized grading of saffron quality according to international ISO specifications.
• High-throughput analysis with sub-second spectral scans and no lamp warm-up delays.
• Integrated reporting exports (CSV, PDF) facilitate compliance, traceability, and LIMS integration.
• Enhanced consumer confidence through reliable adulteration detection and authenticity verification.

Future Trends and Opportunities

• Integration of chemometric and AI-based algorithms for spectral pattern recognition and adulteration detection.
• Development of portable UV-Vis devices for on-site quality assessment in the field or at points of sale.
• Advanced software integration with cloud platforms for remote monitoring and data analytics.
• Expansion of ISO standards to include additional bioactive markers and deeper profiling of saffron origin.

Conclusion

The combined use of the Agilent Cary 3500 UV-Vis spectrophotometer and Cary UV Workstation software enables fast, accurate, and ISO-compliant classification of saffron quality. By quantifying crocin, picrocrocin, and safranal, this approach supports routine laboratory workflows, strengthens quality assurance processes, and boosts consumer trust in high-value spice products.

References

• International Organization for Standardization, ISO 3632-1:2025 – Spices — Saffron (Crocus sativus L.), Part 1: Specification.
• International Organization for Standardization, ISO 3632-2:2010 – Spices — Saffron (Crocus sativus L.), Part 2: Test methods.