Other storage life factors
Harvesting and maturity
Harvest vegetables early in the morning when temperatures are cool. The higher the temperature of the products, the greater the need for refrigeration for cooling and the greater the cost. High temperatures increase the rate of respiration and deterioration. Once harvested, exposure of vegetables to the sun causes shrivelling and rapid quality deterioration.
Before transport to a packing shed, ensure vegetables are kept in the shade in a shed or at least under a tree in a paddock. They should be transported with a cover to the packing shed for pre-cooling no more than four hours after harvesting.
It is very important to harvest vegetables at the correct maturity and size for marketing. The requirements for local and overseas markets often differ.
Environmental factors and nutrition
Keeping quality depends on temperature, light and mineral nutrition during growth, and balanced use of irrigation and pesticides. Calcium is an important nutrient for long storage life.
Products should be as free as possible from breaks, bruises, decay and other damage which increases moisture loss and provides entry points for bacteria and fungi.
Storage areas must be free of ethylene. A natural ripening hormone, ethylene leads to deterioration in vegetables. It is produced by fruit and vegetables as part of their physiological processes. Any damage, bruise, mechanical injury or other kind of stress sustained during harvesting, storage and transportation process will promote ethylene production.
Do not store vegetables with apples, pears, avocados, kiwifruit, stone fruits, tomatoes and melons. More information on Storage of fresh fruit and vegetables and Mixed storage of fruits and vegetables is available.
Suitable packaging can facilitate handling, protect the produce, extend storage/shelf life and help to maintain good quality. Vegetables should be tightly packed with a plastic liner to maintain moisture content in storage, reducing water loss and shrivelling helping to maintain quality.
Active packaging, for example, modified atmosphere packaging using sealed polyethylene bags, creates an atmosphere inside the package which slows the ageing/deterioration process. Active packaging material is a plastic film which can be used as a wrap or liner for produce inside a carton or a pallet.
Additionally, sachets of an ethylene absorber can be added to the packaging. This limits the availability of oxygen and builds up the level of carbon dioxide while absorbing the ethylene. The active packaging film partially blocks the escape of carbon dioxide, but does not allow oxygen to remain above certain limits.