Sustainable Postharvest Handling

Sustainable Postharvest Handling

The world is abuzz with talk of climate change, greenhouse gas emissions, agricultural sustainability, and carbon footprints. At the same time, there is concern about long-term petroleum reserves. Our food system is an important user of fossil fuels and producer of greenhouse gases. Buyers are asking their food suppliers for their carbon footprint along with information about how sustainable their farming practices are. New legislation has been proposed, and in California a new law (AB32) requires a 20% reduction in greenhouse gas emissions across all sectors by 2020 and 80% by 2050.

Recent studies indicate that our food system consumes close to 16% of the total energy use in the U.S., yet only 2% of the total energy is used to grow the food we eat. Since fossil fuels are the predominant energy source, this results in significant greenhouse gas emissions and a large carbon footprint for the food industry. However, the carbon footprint is not the same for all types of food. It varies depending on how they are produced, processed, packaged, and transported.

For example, organic production uses less energy in the form of nitrogen fertilizer than conventional production, but hauling organic chicken manure more than 20 miles can eliminate the advantage. Tomato sauce requires energy to process but it weighs less and requires less energy to ship than the equivalent amount of tomatoes required to make the same amount of spaghetti sauce.

A detailed and systematic analysis of the differences in energy use and greenhouse gas emissions of individual foods is required to allow producers, buyers, and consumers to make informed choices. A life cycle analysis approach is needed to develop a complete understanding of the greenhouse gas emissions of various foods.

Is it more or less sustainable to ship freshly harvested produce items across the globe rather than producing them locally and storing for off-season supply? This depends on the produce item and how it is handled after harvest, and the answer is not always obvious. Products shipped by sea may have a much smaller carbon footprint on a per pound-mile basis than products transported by truck or passenger car in much shorter distances. To enjoy apples produced locally for nearly 12 months of the year, the apples must be kept in refrigerated storage in an atmosphere of low oxygen and elevated carbon dioxide. Marketing these fruit throughout the U.S. involves truck transit to markets that may be thousands of miles away.

Is it more sustainable to buy only produce items produced within 100 miles of home? The distance you must travel by car to purchase these products is critical in the analysis because of the small amount of product transported by automobiles. Compare a refrigerated truck hauling 40,000 pounds of apples with a 6 mile-per-gallon (mpg) efficiency with a car hauling 2 pounds of apples with 20 mpg efficiency. Food miles and carbon footprint must be calculated on a per unit of food basis.

Less Waste, Post Haste

Postharvest technology can make a significant contribution to reducing the carbon footprint of food systems. Energy for cooling can be reduced by using efficient cooling operations and managing them well. In addition, harvesting products during the cooler parts of the day and avoiding exposure to the sun after harvest through the use of shade materials will reduce the heat load that must be removed from the product. Maintaining the cold chain once the product has been thoroughly cooled will prevent the need for re-cooling and reduce energy use. 

Reducing wasted food is something everybody can do to reduce the greenhouse gas emissions in our food system. Depending on the commodity, postharvest losses range from 5% to 25% in developed countries and 20% to 50% in developing countries. A recent survey carried out in the UK claims that an estimated 4.4 million apples are tossed every day along with 5.5 million potatoes, 2.8 million tomatoes, 1.6 million bananas, and 1.2 million oranges due to deterioration problems. Based on these estimates, these five items alone add up to 525,000 tons of food waste a year (according to

The USDA Economic Research Service estimates that in 2005, 57% of fresh fruits and 51% of fresh vegetables, by weight, were not consumed. According to a recent article in the Hindustan Times, up to 30% of food produced in India is wasted because of poor postharvest handling.

Given the electricity, fuel, fertilizer, and water invested in producing a crop, to have 57% of it never consumed is a tremendous waste of resources that greatly increases the carbon footprint of the food industry. The industry has invested in harvest aids, packing equipment, packaging, cooling facilities, storage technologies, and air-ride suspended truck trailers that help maintain the quality of fresh fruits and vegetables, allowing them to make it to market in good condition for purchase and consumption. However, there is still room for considerable improvement, and we should invest at least as much energy and resources into improving postharvest handling as in improving our production practices.

Leave a Reply

Featured Stories

All Vegetables Stories >All Fruits Stories >All Nuts Stories >All Citrus Stories >

The Latest

CitrusMajor Florida Citrus Planting Incentive Program Announc…
September 23, 2014
Citrus World Inc. plans to invest $10 million to encourage new acreage. Read More
Insect & Disease UpdatePositive Attitudes Promote Citrus Planting
September 23, 2014
Improving management methods gives growers confidence in the future. Read More
CitrusNational Farmers Union Submits Comments On Clean Water …
September 23, 2014
Organization urges other industry groups to submit constructive comments. Read More
GenNext GrowersAnnouncing The GenNext Growers Webcast Series
September 23, 2014
This series will present strategies and tips to make your voice heard and count when speaking to legislators. Read More
VegetablesViability On The Menu For Long-Term Vegetable Market O…
September 23, 2014
Economic recovery favorable for climbing consumption trends. Read More
CitrusLuke Bryan Pays It Forward For Farming
September 23, 2014
Country superstar honors agriculture with his Farm Tour. Read More
IrrigationFlorida Growers Seize Control Of Water Challenges
September 22, 2014
New irrigation projects and fertilizer practices have tremendous potential for protecting resources, while enhancing productivity. Read More
CitrusNew Superhero Aims To Save Florida Citrus
September 22, 2014
Unique marketing partnership comes to life through comics. Read More
Apples & PearsKasumin Now Registered For Fire Blight Control
September 22, 2014
EPA approves use of bactericide on pome fruit as disease management tool. Read More
Food SafetyUSDA Issues Updates To Food Safety Modernization Act
September 19, 2014
Water testing, definition of applicable farms based on produce sales among clarifications to proposed rules. Read More
GrapesThird Straight Record Crop For Washington Grapes
September 19, 2014
Numbers expected to climb as more vines planted in the state. Read More
GrapesFrench Winegrowers Face Higher Labor Costs
September 19, 2014
French wineries may come under added financial pressure as the government considers imposing social charges on wages paid to harvest workers with short-term contracts. Read More
IrrigationCalifornia Boosts Local Water Control
September 19, 2014
Governor Jerry Brown signs historic legislation to strengthen local management and monitoring of critical groundwater basins. Read More
VegetablesSakata Seed America Shows Heart Through Charitable Prog…
September 19, 2014
Company’s corporate giving mission bears fruit for the American Heart Association. Read More
Insect & Disease UpdateAdditional Aid Coming For Florida Citrus Growers Gouged…
September 17, 2014
Through USDA’s Tree Assistance Program, eligible growers can cash in on cost share for diseased tree removal and replanting. Read More
FruitsFlorida Fruit & Vegetable Association Seeks Fresh A…
September 17, 2014
New partnership bolsters Fresh From Florida program. Read More
CitrusFDA Announces Cooperative Agreement To Implement Nation…
September 17, 2014
Agreement will provide information to help plan and carry out the produce safety rule in partnership with state regulatory agencies. Read More
NutsAchieving A Super-Premium Walnut Crop
September 17, 2014
What are the best ways to get high quality walnuts that are light in color and fully developed? Read these 8 harvest best practices to find out. Read More