POSTHARVEST FOOD LOSS OR FOOD WASTE?
Recently issues of global food losses and food waste have been making the news, with estimates of 30 to 40% of all the food produced on earth going to waste before it can be consumed. Global food losses and waste (sometimes referred to as FLW) vary widely depending upon the type of food, and can occur on the farm, and during postharvest handling, food processing, storage, distribution and consumption (Gustavsson et al 2011).
The Postharvest Education Foundation is involved in work to address both postharvest food losses and food waste by providing information, advice, training and mentoring of young professionals who are involved in the fields of agriculture, horticulture, home economics and food processing.
Postharvest food losses - occurring at the production, harvest, postharvest and processing phases - are the most important source of FLW in developing countries, due to poor infrastructure, poor temperature management, low levels of technology and low investment in the food production systems, especially the cold chain.
Key factors affecting food losses and the gaps in knowledge/skills that we have identified:
- Poor understanding of harvest indices of plant foods and how maturity is related to quality and shelf life.
- Poor sorting and grading practices during preparation for market, allowing damaged /decaying foods to enter the supply chain and to spread decay to other foods.
- Poor temperature management and lack of control of relative humidity, leading to shriveling, wilting and deterioration of perishable foods.
- Poor quality packages which provide little or no protection during handling, transport and storage.
- Delays in transport to market without proper storage (cool storage for perishables, drying of staple grains/beans/legumes before storage).
- General lack of education on appropriate postharvest handling practices and technologies, leading to rough handling, mechanical damage, improperly handled mixed loads, and food safety concerns.
- Lack of the utilization of sustainable, cost effective postharvest practices, leading to high levels of food loss on the farm, and in wholesale and retail markets.
Food waste is more of a problem in industrialized countries, most often caused by both retailers and consumers throwing perfectly edible foodstuffs into the trash. According to a SAVE FOOD Initiative report, per capita waste by consumers is between 95-115 kg/year in Europe and North America, while consumers in sub-Saharan Africa and South and Southeast Asia each throw away only 6-11 kg/year (Gustavsson et al 2011).
Key factors affecting food waste and the gaps in knowledge/skills that we have identified:
- Over-sorting and over-grading on the farm and in the packinghouse, based on strict guidelines that have more to do with appearance (color, size, shape) than nutritional value or eating quality, leading to higher discards of edible foods.
- Poor choice of packages and packaging materials, with focus on cosmetic features rather than on strength, cleanliness, ventilation, moisture control, etc., which would help extend shelf life.
- Over-reliance on long term cold storage, refrigeration and freezing, leading to development of off-flavors, chilling injury and freezer burn, causing discards of improperly stored foods along the supply chain.
- Confusing or unnecessary “sell-by” or “use-by” dates, based upon cosmetic changes or inventory management schemes rather than on food safety concerns, leading to waste of edible foods at the retail level.
- Lack of education regarding proper packaging, cooling/cold storage, storage of cooked foods and reusing left-over foods, leading to increased discards of foods in the home.
The UN FAO SAVE FOOD Initiative report summarizes the issues and highlights the need for taking action (Gustavsson et al 2011). The report distinguishes between food loss and food waste and is available online for free download.