ISO 23036-1:2021

Overview

ISO 23036-1:2021 - "Microbiology of the food chain - Methods for the detection of Anisakidae L3 larvae in fish and fishery products - Part 1: UV-press method" specifies a validated visual screening method for detecting third‑stage (L3) Anisakidae larvae in marine and anadromous fish. The UV‑press method is applicable to fresh, frozen and lightly processed fish (for example marinated, salted or cold‑smoked products) and is intended to quantify parasite burden in fish musculature. This part does not determine parasite species/genotype; final identification requires morphological or molecular methods.

Key topics and technical requirements

• Principle: Frozen Anisakidae L3 larvae fluoresce under 366 nm UV light (due to lipofuscin). Flattened, frozen fillets are examined under UV to reveal brightly fluorescent larvae.
• Sample preparation:
  • Eviscerate and fillet fish; remove thick skin where necessary.
  • Place fillets in clear LDPE bags (example size 300 × 700 mm × 0.075 mm).
• Pressing:
  • Use a hydraulic press (manual or automatic) at 7–8 bar to obtain a thickness of 1–2 mm; hold at least 5 s.
• Freezing and thawing:
  • Freeze pressed samples at −20 °C until solid (commonly ~24 h). If already frozen, additional freezing is optional.
  • Thaw at ≥4 °C (not exceeding room temperature). Inspect within 12 h after thawing to avoid fluorescence loss.
• Inspection:
  • Examine in a dark room under a 366 nm UV source (up/down lighting recommended; Philips TL‑D 18 W BLB cited as example).
  • Record larvae as bright fluorescent spots and note approximate location (dorsal/ventral).
• Results reporting:
  • Express as present/absent and number of larvae per X grams / per fillet section.
• Safety & quality:
  • Use UV eye/skin protection; follow ISO 7218 for laboratory practice. No internal QC control is defined in the method.
• Performance:
  • Method performance was established by a multi‑centre ring trial; reported accuracy and sensitivity were 100% (95% CIs provided in the standard).

Applications and users

This standard is intended for:

• Food testing laboratories performing parasitological screening of fish and fishery products
• Seafood processors and quality assurance teams within the supply chain (HACCP monitoring)
• Regulatory agencies and inspection bodies enforcing food safety controls
• Research laboratories studying fish parasite prevalence and distribution

Practical benefits: rapid, economical screening for Anisakidae L3, quantitative estimation of infestation level in fillets, suitability for a wide range of fresh, frozen and lightly processed seafood.

Related standards

• ISO 7218 - Microbiology of food and animal feeding stuffs: general requirements and guidance for microbiological examinations
• Other parts of the ISO 23036 series (see ISO website for full list)

Keywords: ISO 23036-1:2021, UV‑press method, Anisakidae L3 larvae, fish parasite detection, food safety, seafood inspection, microbiology of the food chain.