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

Quality Assessment of Saffron by UV-Vis Spectroscopy

Significance of the Topic

Saffron, one of the world’s most expensive spices, commands a high market value that directly depends on its quality, purity and authenticity. Its distinctive color, aroma and flavor derive from bioactive compounds—crocin, picrocrocin and safranal. Ensuring reliable quality grading not only protects consumer trust and safety but also safeguards producers against adulteration. UV-Vis spectroscopy, standardized by ISO 3632, offers a rapid, non-destructive approach for routine saffron analysis.

Objectives and Study Overview

This study applied ISO 3632-1:2025 and ISO 3632-2:2010 test methods to grade a commercial saffron sample. Using an Agilent Cary 3500 UV-Vis Multicell spectrophotometer and the Cary UV Workstation software, the aim was to quantify moisture content and the concentrations of the three key saffron constituents. The final goal was to classify the sample into one of four commercial grades (Extra Class, I, II, III) based on defined absorbance-strength criteria.

Methodology and Instrumentation

Sample Preparation and Moisture Determination

• Weighed 2.5018 g of saffron filaments, dried at 100 ± 1 °C for 16 h, and reweighed to calculate moisture and volatile matter (wMV = 6.43 %).
• Crushed 1 g of filaments, extracted in 900 mL distilled water with stirring, and filtered the aqueous solution through a 0.45 µm membrane.

Instrumentation

• Agilent Cary 3500 Multicell UV-Vis spectrophotometer with xenon flash lamp, eight-cell carousel, double-beam fiber optics.
• Agilent Cary UV Workstation software for sequence setup, automated absorbance measurement and strength calculations.

Analytical Procedure

• Measured UV-Vis spectrum from 200 to 700 nm; recorded absorbance at 257, 330 and 440 nm corresponding to picrocrocin, safranal and crocin, respectively.
• Calculated strength values (1 % 1 cm) using ISO-defined equations adjusted for sample mass (0.5330 g) and moisture content.

Main Results and Discussion

The moisture content (6.43 %) met the Extra Class limit (< 12 % for filaments). Absorbance values (257 nm: 0.5156; 330 nm: 0.2035; 440 nm: 1.3351) yielded strength values of 103.38 (taste), 40.81 (aroma) and 267.70 (color). All three parameters exceeded the Extra Class minimum specifications (taste ≥ 80, aroma ≥ 20, color ≥ 230), confirming the sample’s top-grade status. The integrated software workflow minimized manual calculations and transcription errors, while producing clear spectral plots and tabulated results.

Benefits and Practical Applications

Using the Cary 3500 UV-Vis and Cary UV Workstation enables rapid, high-throughput saffron quality assessment in research and industrial QA/QC settings. The xenon lamp allows instant full-spectrum scans, reducing analysis time. Automated sequence control and ISO-compliant calculations enhance reproducibility and traceability. Exportable CSV and PDF reports support LIMS integration, regulatory compliance and audit readiness.

Future Trends and Potential Applications

Advances may include coupling UV-Vis with chemometric models or portable fiber-optic probes for in-field saffron authentication. Integration with machine learning could detect subtle adulteration patterns. Expanding the approach to other spices and natural products under ISO guidelines can standardize quality control across the food industry.

Conclusion

The combination of Agilent Cary 3500 UV-Vis spectrophotometer and Cary UV Workstation software delivers a streamlined, ISO-compliant workflow for saffron quality grading. Precise quantification of moisture, color, taste and aroma markers supports reliable commercial classification and combats adulteration. Automated data acquisition and reporting accelerate routine analysis and ensure traceable documentation.

Reference

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