Post-Harvest Food Loss

Losses accumulate through the post-harvest chain. Grain may be lost as spillage and incomplete threshing, then to insects and moulds if it is stored too moist or too warm. Perishable fruit and vegetables may be lost to bruising, decay, and quality decline when they are not cooled promptly or handled carefully, or when they cannot reach a market in time. Each handling step is an opportunity both for loss and for prevention.

A common distinction is between quantitative loss — a reduction in the weight of food available — and qualitative loss — a decline in quality, nutritional value, or safety that lowers value even when the food is not physically gone. Both matter, and mycotoxin contamination is an example where a quality and safety loss can make otherwise intact grain unusable.

• Dry grain promptly and store it clean, cool, and protected from insects and moulds.
• Cool perishables quickly after harvest and keep the cold chain intact.
• Handle and package produce carefully to limit bruising and damage.
• Sort and grade to remove unsound units and direct produce to suitable markets.
• Improve access to storage, processing, transport, and markets so food reaches consumers in time.

Because losses arise at many points, the most effective approach usually addresses the whole chain rather than a single step. Improvements in drying and storage tackle grain losses, while cooling, careful handling, and better market access tackle perishable losses.

Reducing post-harvest loss increases the amount of food available and the income farmers earn from a given harvest, without the additional land, water, and inputs that producing more food would require. For this reason it is a central theme in food-security and sustainability efforts, and it provides the practical rationale for the drying, storage, cooling, handling, and quality operations described elsewhere in this collection.