Overview
ISO 3033-4:2005 - "Oil of spearmint - Part 4: Scotch variety (Mentha × gracilis Sole)" is an international standard that defines quality characteristics and test requirements for Scotch spearmint essential oil. The standard establishes sensory and physico‑chemical criteria, a normative chromatographic profile, and references for sampling, testing and packaging to facilitate consistent quality assessment and trade of this specific oil of spearmint.
Key topics and technical requirements
The standard specifies observable properties and laboratory limits used in quality control of Scotch spearmint (Mentha × gracilis Sole):
- Appearance & colour: clear mobile liquid; colourless to pale yellow.
- Odour: characteristic carvone‑type scent with herbaceous note.
- Relative density (d20): 0.9210 – 0.9380 (ISO 279).
- Refractive index (n20): 1.4840 – 1.4910 (ISO 280).
- Optical rotation (20 °C): between −59° and −48° (ISO 592).
- Miscibility in ethanol (70 % v/v): ≤ 3 volumes of ethanol required for 1 volume oil (ISO 875).
- Carbonyl value: minimum 224 (test portion 1 g; reflux 3 h) corresponding to ~60 % carvone (ISO 1271).
- Chromatographic profile (GC): normative GC component ranges (integrator %):
- Carvone: 60.0 – 70.0 %
- Limonene: 11.5 – 16.5 %
- 3‑Octanol: 0.6 – 1.4 %
- trans‑Sabinene hydrate: 0.5 – 1.0 %
- cis‑Dihydrocarvone: 1.0 – 2.5 %
- trans‑dihydrocarvyl acetate / cis‑carvyl acetate / cis‑jasmone / β‑bourbonene: specified minor ranges; Viridiflorol: not detectable.
Gas chromatography methods and presentation follow ISO 11024‑1 and ISO 11024‑2.
- Flashpoint (informative): mean value reported ≈ +58 °C (Setaflash).
Additional procedural details: sampling reference (ISO 212), minimum sample volume 50 ml for testing.
Applications and users
ISO 3033-4:2005 is used by:
- Essential oil producers and distillers to specify Scotch spearmint oil quality.
- Quality control and analytical laboratories for acceptance testing and batch release using GC and physico‑chemical tests.
- Flavor and fragrance formulators and perfumers to ensure ingredient consistency (carvone content critical).
- Buyers, traders, and regulatory bodies for product specification, labeling, storage and transportation safety information.
- Customs, certification bodies and procurement teams for contract compliance and dispute resolution.
Practical applications include raw material specification, supplier qualification, incoming inspection, product formulation decisions, and safety classification.
Related standards
- ISO 3033 series: Part 1 (native), Part 2 (Chinese), Part 3 (Indian).
- Test method and guidance references: ISO 279, 280, 592, 875, 1271, 11024‑1/2, ISO/TR 210, ISO/TR 211, ISO 212 and ISO/TR 11018 (flashpoint guidance).
Keywords: ISO 3033-4:2005, oil of spearmint, Scotch spearmint, Mentha × gracilis Sole, carvone, gas chromatography, chromatographic profile, essential oils standard.