Overview
ISO 3959:1977 - "Green bananas - Ripening conditions" defines recommended postharvest ripening protocols for green bananas intended for international trade. The standard describes pre-ripening factors, placing and loading in the ripening room, heating procedures, ripening phases, the action and safe use of ethylene, post-ripening storage temperatures, target degrees of ripeness at supply, and common causes of defective ripening. It was developed by ISO/TC 34 (Agricultural food products) and complements storage and transport guidance.
Key topics and technical requirements
- Pre-ripening assessment: degree of development at harvest is judged by fruit fullness on the bunch; external and physiological conditions during handling and transport strongly influence ripening performance.
- Placing and loading: hands/parts of hands are usually sent in corrugated fibreboard cases; recommended loading density in the ripening room is 150–200 kg/m³; maintain airflow corridors between pallet rows.
- Heating stages:
- Preliminary heating: natural warming if external temperature >12 °C; artificial heating if below 12 °C to prevent cold injury.
- Supplementary heating: raise flesh temperature progressively to the target ripening temperature (typically 16–18 °C) in a humid, closed-circuit atmosphere.
- Ripening phases: two physiological phases - an initial climacteric heat and respiration rise, then a decline accompanied by starch hydrolysis and skin colour change. Maintain relative humidity ≈95% during ripening and keep air circulation to homogenize temperature.
- Ethylene use: ethylene accelerates and standardizes ripening of otherwise unripe fruit. Typical treatment uses ~1 000 ppm (1 part per 1 000) ethylene or controlled nitrogen/ethylene mixtures supplied from cylinders placed outside the room; room should remain closed for 24 hours after introduction. Note: national regulations on ethylene use apply.
- Ripening schedules: example regimes in the standard include rapid (≈4 days), normal (5–6 days) and slow (≈8 days) ripening with day-by-day temperature and humidity guidance.
- Post-ripening storage & supply: target flesh temperature after ripening is about 13.5–14 °C for summer supply (turning yellow); in cold weather supply, fruit may be firmer/yellower with flesh temperature around 16 °C.
- Causes of defective ripening: cold injury, dehydration, low RH, injuries, uneven development, fungal infections.
Applications and who uses it
ISO 3959 is practical for:
- Banana ripeners and packing houses setting up ripening-room protocols
- Importers, wholesalers and retailers managing delivery ripeness
- Cold-chain and logistics managers coordinating transport and pre-ripening handling
- Quality assurance and postharvest researchers developing SOPs for banana ripening
- Regulators and auditors assessing commercial ripening practices
Keywords: ISO 3959, green bananas, ripening conditions, ethylene treatment, ripening room, banana ripening, storage temperature, postharvest handling, ripening protocols.
Related standards
- ISO/R 931 - Green bananas - Guide to storage and transport (referenced by ISO 3959)
