The Science of Herb Quality: Moisture, Volatile Oil, and Color Explained

Herbs may look simple, but their quality depends on precise scientific parameters.At Tuna Sourcing, every shipment is tested for physical and chemical consistency — ensuring that importers receive stable, high-grade herbs ready for industrial use.

Moisture – The Foundation of Stability

Why It Matters

Moisture defines shelf life and microbial safety.Too much leads to mold and discoloration; too little causes breakage and aroma loss.The ideal range for most herbs lies between 8–12%, depending on species and destination climate.

Controlled Drying and Verification

Tuna Sourcing uses calibrated moisture analyzers and temperature-controlled dryers.Results are logged and compared to international export norms before packaging.

Volatile Oil – The Heart of Aroma

Measuring Aromatic Strength

Volatile oil content determines aroma intensity and value in the international market.Using steam distillation and GC (Gas Chromatography) analysis, we quantify essential oil concentration for herbs such as oregano, thyme, and sage.

Quality Benchmarks

• Oregano: ≥ 2.0%

• Thyme: ≥ 1.5%

• Bay Leaves: ≥ 1.0%Higher oil levels signify fresher harvests and correct drying conditions — key indicators of premium quality.

Color – The Visual Signature of Quality

Natural Pigments and Oxidation

Color reflects proper drying and storage.Bright green tones indicate freshness; dull brown shades signal oxidation or overheating during drying.

Visual Grading and Optical Sorting

We employ optical sorters to remove off-color particles and impurities.This ensures a clean, uniform appearance — critical for both retail packaging and industrial blending.

Integrated Herb Quality Control at Tuna Sourcing

Lab Testing and Documentation

Every batch includes a Certificate of Analysis (COA) showing test results for moisture, oil, color, and foreign matter.All parameters are aligned with ISO and EU standards for food ingredients.

Digital Traceability

Results are stored in our digital database and can be shared instantly with importers — enabling transparency and confidence in every order.

Quality is measurable, verifiable, and repeatable — and that’s exactly how Tuna Sourcing maintains its global reputation.Each herb we ship reflects a balance of tradition, science, and precision.