ISO 18731:2025 PDF

Overview

ISO 18731:2025 - Spices and condiments: Seasoning oil of Zanthoxyli pericarpium - Specification - defines quality, safety and labelling requirements for seasoning oil produced from Zanthoxyli pericarpium (prickly ash / Sichuan pepper) fruits. The standard standardizes sensory, physicochemical and contaminant criteria, test methods (including annexed procedures), and packaging, storage and transport rules to support consistent production, testing and international trade.

Key Topics and Requirements

• Scope: Applies to seasoning oil of Zanthoxyli pericarpium produced by extraction, cold pressing, supercritical CO2 or dilution into vegetable matrix oil.
• Sensory requirements: Appearance (clear oily liquid), colour under sunlight, characteristic Zanthoxyli flavour and taste; free from foreign flavours/tastes.
• Physicochemical limits:
  • Acid value (KOH): max 3.0 mg/g (Grade I & II) - ISO 660
  • Peroxide value: max 20.0 meq/kg - ISO 3960
  • Moisture: max 0.8 g/100 g - ISO 662
  • Amides (key active compounds, e.g., sanshools): Grade I min 5.0 mg/g; Grade II min 4.0 mg/g - tested by Annex B (UV spectrophotometry)
  • Residual solvents: testing by Annex C or ISO 9832; values