Storage conditions
Minimum quality requirements are that carrots should be intact, sound, clean, free from attack by diseases, pests, mould or rot, and without foreign smell or taste.
- Storage life depends on storage temperature and humidity.
- At 20°C and 60–70% relative humidity, carrots will keep for two to three days.
- At 4°C and 80–90% relative humidity, carrots will keep for one to two months.
- At 0°C and greater than 95% relative humidity, carrots will keep for up to six months.
- The ideal conditions for best keeping quality are pre-cooling and storage at 0°C and 95–100% relative humidity.
- The recommended temperature for storage is 0 to 2°C.
General facts
- Ideally, carrot should be cooled to below 5°C within 24 hours of harvest.
- Preferred cooling methods are hydro-cooling, forced-air cooling or hydro-vacuum cooling.
- Ideal conditions for long-term storage are at 0°C and greater than 95% relative humidity.
- Carrots freeze at about –1.4°C.
- Carrots are susceptible to dehydration. Silvering (‘white scale or white blush’) results from dehydration of the partially removed outer skin (periderm) of carrots. Further dehydration results in development of phenolic browning in tissue beneath the periderm. Use of liners during storage and transportation increases moisture retention, reduces dehydration, and hence reduces silvering and phenolic browning.
- Brush polishing removes the periderm from carrots solving the silvering problem but exposing roots to phenolic browning. Browning is initiated by physical damage of the surface during harvest and postharvest brushing, thereby exposing the internal tissue to oxidation. Browning usually develops when carrots are on the market shelf after a period of cold storage.
- Carrots are sensitive to ethylene, so avoid mixed storage with ethylene-producing produce such as tomatoes, melons, apples, pears, plums, kiwifruit and avocados. Ethylene causes development of bitter flavours by stimulating production of compounds called isocoumarins.
- Available chlorine at 50 to 100 parts per million (ppm) in clean rinse water reduces likelihood of bacterial and fungal breakdown. For chlorine to be effective, water pH has to be maintained from 7.0 to 7.6.
- There is no advantage in holding whole fresh carrots under controlled atmosphere storage.
Packaging checklist
- Common name or description of product
- Net weight or volume
- Country of origin
- Date of packaging
- Special storage requirements
- 'Perishable' and 'Handle with care' sign
- Certification logos such as SQF quality assurance, if applicable
- Packer/grower code