Overview
ISO 7543-2:1993 specifies a high-performance liquid chromatography (HPLC) method for determining the total capsaicinoid content of chillies (typically Capsicum frutescens L.), powdered chillies and chilli oleoresins. Total capsaicinoids are calculated from the sum of capsaicin, nordihydrocapsaicin and dihydrocapsaicin, expressed as nonyl acid vanilylamide (synthetic capsaicin) as the reference substance. The method covers sample preparation, extraction, chromatographic separation and quantification, and enables separation of capsaicin and the chosen reference compound.
Key Topics and Requirements
- Scope: HPLC determination of total capsaicinoids in whole, powdered chillies and oleoresins.
- Reference substance: Nonyl acid vanilylamide, ≥95% purity (handled with caution due to irritation).
- Sample preparation:
- Powdered chillies: verify particle size (passes 500 µm sieve), Soxhlet extraction with tetrahydrofuran (THF).
- Whole chillies: grind to pass 500 µm then extract as for powder.
- Oleoresins: homogenize and dilute in THF/methanol (50/50 V/V).
- Extraction and solvents:
- Tetrahydrofuran for extraction; tetrahydrofuran/methanol (50/50) for dilution.
- Elution solvent prepared by mixing methanol and aqueous silver nitrate (70:30 by volume).
- Note: silver nitrate and some reagents require careful handling.
- HPLC system:
- C18-type (grafted silica, octadecyl) column, length 10–25 cm, ID 0.4–0.5 cm, particle size ≤5 µm.
- Detector set at 280 nm; injection loop ~10 µl or equivalent.
- Calibration and calculation:
- Prepare reference stock (1 g/L) and standards (0.05–0.2 g/L) to build calibration curve.
- Determine response factor K and calculate total capsaicinoid content using peak areas for capsaicin, nordihydrocapsaicin and dihydrocapsaicin. A default dilution factor of 500 is given (adjustable by analyst).
Applications and Users
This ISO standard is practical for:
- Food and spice testing laboratories performing quality control and potency testing of chillies and chilli oleoresins.
- Spice processors and oleoresin manufacturers verifying product consistency and label claims.
- Regulatory agencies and trade laboratories assessing capsaicinoid levels for safety, authenticity and trade specifications.
- Research labs studying pungency, processing effects or variety comparisons where precise HPLC quantification is required.
Keywords: chillies, chilli oleoresins, capsaicinoid, capsaicin, HPLC, high-performance liquid chromatography, ISO 7543-2:1993, capsaicinoid determination.
Related Standards
- ISO 7543-1 - Chillies and chilli oleoresins: spectrometric method (other part of the same series).
- ISO 2825 - Preparation of a ground sample for analysis.
- ISO 948 - Sampling of spices and condiments.