ISO 7922:1985

Overview

ISO 7922:1985 - Leeks: Guide to cold storage and refrigerated transport provides practical guidance for maintaining the quality of Allium porrum (leeks) during postharvest handling, cold storage and refrigerated transport. The standard describes recommended harvesting criteria, storage-room preparation, optimum storage parameters and packing/transport practices to reduce deterioration and extend shelf life. An annex outlines the limits of application and notes that local cultivar and climatic variations may require adjustments.

Key topics and requirements

• Harvest quality: Use commercially sound leeks from suitable varieties; minimum stem diameter ≥ 2.5 cm and bulb (white) height ≥ 10 cm. Produce must be whole, free from abnormal surface moisture, mechanical injury, frost damage, fungal disease and soil pests.
• Storage preparation: Refrigeration rooms should be disinfected, deratised, aerated and precooled before receiving produce. Limit handling during intake.
• Optimum storage conditions:
  • Temperature: between −1 °C and +0.5 °C.
  • Relative humidity: 90% ± 5%.
  • Storage duration: typically 2–3 months, with up to 6 months possible under favorable conditions and high initial quality.
• Packing and in-store handling:
  • Store leeks loosely in crates or tied in loose bunches of 10–12 like-sized units to allow air circulation.
  • Perform weekly (or as needed) health checks and adjust conditions accordingly.
  • On removal, trim off wilted leaves and other undesirable material so the white portion is clean; pack by grade and calibre.
  • When bringing produce from cold storage to warmer environments, raise temperature gradually to avoid surface condensation.
• Refrigerated transport: Use nationally standardized packaging and maintain the same temperature and humidity conditions during transport as in storage.

Applications and who uses it

ISO 7922 is intended for professionals involved in the leek cold chain and postharvest management:

• Growers and packers setting harvest and grading specifications
• Cold storage operators and warehouse managers
• Refrigerated transport and logistics providers
• Quality assurance and food-safety teams
• Buyers, wholesalers and produce retailers seeking shelf-life guidance
• Extension services and postharvest advisors

Following ISO 7922 helps reduce spoilage, preserve marketable quality and support consistent cold-chain operations for leeks.

Related standards

This guide was developed by ISO/TC 34 (agricultural food products). For a complete cold-chain program, consult other ISO and national standards addressing refrigerated transport, packaging and general postharvest practices developed for fruits and vegetables.