New OIV resolution about chitosan origin

The OIV has recently taken a big (and very welcome) step toward clearer, tougher authentication of chitosan origin in winemaking. With Resolution OIV-OENO 728-2025, the International Organisation of Vine and Wine formally introduces a new analytical approach to prove whether chitosan is of fungal origin—and to rule out any crustacean (animal) origin.

What’s new?

Until now, the International Oenological Codex already defined three analytical characteristics to verify compliance of chitosan used in oenology. The new resolution adds a fourth, science-backed “ID check”:
Stable Isotope Ratio (SIR) analysis, based on δ¹³C and δ¹⁵N measurements, performed using isotope ratio mass spectrometry (IRMS) (typically coupled with an elemental analyser).
This method was developed by Fondazione Edmund Mach (Italy) and validated through the OIV expert process (SPECIF group), making it a new global reference for demonstrating fungal origin.

Why it matters for the wine industry

This isn’t just a technical update—it’s a practical shield for the whole supply chain:
Traceability: stronger proof of raw material authenticity.
Transparency: more confidence in labelling and compliance.
Quality assurance: better protection against misleading claims and non-compliant sourcing.
And there’s an important regulatory point behind all this: in oenology, the OIV retains only fungal chitosan from safe sources like Aspergillus niger (and Agaricus bisporus)—not animal-derived material.

What does the SIR method actually check?

SIR distinguishes fungal vs. crustacean origin via isotope “signatures.” In the updated framework, fungal origin can be supported by δ¹³C / δ¹⁵N thresholds (as described in the resource article), providing an extra layer of certainty beyond the existing Codex checks.
The new official method is described as the determination of ¹³C/¹²C and ¹⁵N/¹⁴N isotopic ratios by IRMS, and is now referenced under OIV-OENO 728-2025 (certified June 20, 2025).

What this means for us (and for customers)

This resolution gives customers a very concrete lever: they can request analytical proof from suppliers to ensure Codex compliance for chitosan-based oenological products.

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