College of Agriculture and Environmental Sciences

Reducing Post-Harvest Losses

Post-harvest loss is a major contributor to food scarcity; each year, around 50 percent of the harvest is lost during harvesting, post-harvest handling, storage, processing, distribution and consumption. It’s imperative that suitable post-harvest packaging, transportation and storage practices are used to reduce post-harvest loss.

Harvest Timing

Timing your harvest is critical, since timing impacts the quality of fresh fruits and produce. The crop should be harvested only when it has the correct appearance and taste.

If the product is too mature or too immature, it will also have lower quality. Immature crops are more prone to mechanical injury and may have high acidity and lower sugar. On the other hand, overripe fruits have a short shelf life. The grower/producer should know the relevant harvest parameter for each crop. Be sure farm workers receive training on how to recognize ready-for-harvest crops.

Harvesting Factors

Setting harvesting time, standardizing manual and mechanical harvesting methods, and determining appropriate devices are vital variables. Approaches such as hydro-cooling, room cooling, forced air cooling and serpentine forced cooling can be utilized. A variety of harvesting basins can be used, including basket containers, sacks, carts, and buckets made of plastic, wood or engineered fibers.

Check Your Water Quality

All water used for washing produce must be potable (drinkable). Well water must be tested for bacteria; municipal water does not need to be tested. You must never use surface water, such as stream and pond water, for postharvest applications or washing produce. Surface water commonly harbors bacteria and pollution from animals, runoff and other sources.

If you use a dunk tank to wash produce, frequently check your water and change it if needed. As more produce from the field is dunked into the tank for washing, the water can become contaminated and spread bacteria to other fruits. To sanitize produce, you can use sodium hydrochloride, bleach, hydrogen peroxide, peroxyacetic acid or ozone. Using any of these sanitizers and checking the water frequently will prevent transferring pathogens from one fruit to another.

As often as possible, check the water temperature to ensure that it isn’t too cold. The temperature of produce coming from the field has to be about the same as the washing water. If the water is too cold, the fruit can suck in water at its cutting point, damaging its interior. After the items cool down and the tissues contract, a vacuum is created, causing water and pathogenic life forms suspended within the water to be drawn into micro-wounds or other characteristic openings within the produce.

Avoid Damage

Cuts or splits within the fruit create access points for microorganisms. To avoid this, make sure that harvest tool blades are sharp and workers are adequately trained to do the job. The cutting knife blade must also be clean. When moving fruit from the field to the packing house, make sure not to overload the truck to avoid the bottom fruits from being crushed or compressed. Also, be sure to load trucks gently. To prevent bruising, don’t toss the product onto the truck.

Keep Your Produce Cool

Always harvest in the morning when it is cooler, and keep the fruits and vegetables out of direct sunlight. After harvesting, move the item to the processing building as soon as possible. Quickly move the product into a cooler after preparing. Strategies to extend the cooling rate incorporate forced cooling (inside the capacity room), hydro cooling and, in some cases, icing.

Packaging

Proper packing materials can prevent injury to produce during transportation and storage. 

Possible reasons for fresh fruit and vegetable losses
Potential packaging solutions
Possible reasons for fresh fruit and vegetable losses:  
Bruising due to compression of overfilled packages
Potential packaging solutions:  
Use light and smooth surface containers. Decrease the weight of produce in containers.
Possible reasons for fresh fruit and vegetable losses:  
Vibration inujury (such as brusing, cracking)
Potential packaging solutions:  
Improve transport packaging for shipping. Use restrainers, individual wrapping or cushioning.
Possible reasons for fresh fruit and vegetable losses:  
Impact injury
Potential packaging solutions:  
Use firm containers with individual cushioning.
Possible reasons for fresh fruit and vegetable losses:  
Puncturing injury
Potential packaging solutions:  
Use rigid containers with proper grips, and smooth containers and handling equipment.
Possible reasons for fresh fruit and vegetable losses:  
Water loss/drooping
Potential packaging solutions:  
Modified Atmosphere Packaging (M.A.P.)
Possible reasons for fresh fruit and vegetable losses:  
Inadequate ventilation
Potential packaging solutions:  
Use packaging materials allowing respiration

References