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 www.lovefoodhatewaste.com).

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
Judi Whitson, 2016 Florida Woman of the Year in Agriculture
Citrus
April 24, 2017
Who Will Be Florida’s next Woman of the Year in Agriculture?
Nomination period now open for longstanding recognition from FDACS. Read More
Apples & Pears
April 24, 2017
Researcher Uncovers the Origins of ‘Honeycrisp’ Apple
Thanks to the scientific data available through gene sequencing, a graduate student unlocks the mystery parentage. Read More
Citrus
April 23, 2017
Bio Huma Netics, Inc., and Mesa Verde Resources Expand Product Selection
Strategic alliance between the two companies is designed to offer customers greater access to products. Read More
GenNext Growers
April 22, 2017
Next Generation of Leaders Gets Yearlong Almond Immersion
Almond Leadership Program enters its ninth year with the 2017 class. Read More
Washington Capitol building
Citrus
April 21, 2017
Alliance Stepping Up Efforts to Protect Specialty Crops
The Specialty Crop Farm Bill Alliance has kicked off its efforts to communicate to Congress its priority needs for the Read More
glass of red wine
Grapes
April 20, 2017
Would You Be Willing to Pay More for Organic Wine?
While consumers might be ready to fork over more for organic produce, study says the feeling isn't quite the same when it comes to the adult beverage. Read More
UF/IFAS scientist Jonathan Crane inspects avocado trees in South Florida
Crop Protection
April 20, 2017
Beetle Battle Burgeoning for South Florida Avocado Growers
Scientists identify more species of pests that vector deadly fungus. Read More
farm labor pic for web
Citrus
April 20, 2017
Farm Labor Is in Crisis
To have a great crop potentially rot in the field because workers can’t be sourced is probably worse than a weather event taking out production. Read More
Zellwood, FL, muck farming history photo
Vegetables
April 19, 2017
Free Forum to Hail Florida Muck Farming History
Zellwood Historical Society helping shine a light on an industry that defined the area. Read More
Vegetables
April 19, 2017
Want Low Drama Food Safety Inspections? Embrace Paperwork [Opinion]
When I was in high school, my mom was the administrator of an outpatient hospital. Like all hospitals, Mom’s was Read More
Vegetables
April 19, 2017
Which Vegetable Crops Are the Most Popular?
The editors at American Vegetable Grower asked growers about their crops as part of our 2017 State of the Vegetable Industry survey, and gained a lot of insight into which crops are most commonly grown, and how well those crops are performing. Read More
Grapes
April 19, 2017
Donnell Brown Named President of National Grape & Wine Initiative
New president brings experience in wine industry communications. Read More
Alternaria Leaf Spot of Cucurbits
Cucurbits
April 19, 2017
Alternaria Leaf Spot Awareness Can Save Your Cucurbit Crops
Learn how to identify, the survival and spread, as well as management methods for this malady. Read More
Apples & Pears
April 19, 2017
Young Apple Growers Meet with Lawmakers
Apple leaders from across the country discuss ag issues such as labor, trade, and research. Read More
Barnes Farm cabbage field in Hastings, FL
Citrus
April 18, 2017
Florida Growers Seeking Inspiration Need Not Look Far
The firsthand experience of speaking with farmers and actually seeing all the hard work, knowledge, ingenuity, and people behind where our food comes from is invaluable. Read More
The Latest
Citrus
April 24, 2017
Who Will Be Florida’s next Woman of the …
Nomination period now open for longstanding recognition from FDACS. Read More
Apples & Pears
April 24, 2017
Researcher Uncovers the Origins of ‘Hone…
Thanks to the scientific data available through gene sequencing, a graduate student unlocks the mystery parentage. Read More
Citrus
April 23, 2017
Bio Huma Netics, Inc., and Mesa Verde Re…
Strategic alliance between the two companies is designed to offer customers greater access to products. Read More
GenNext Growers
April 22, 2017
Next Generation of Leaders Gets Yearlong…
Almond Leadership Program enters its ninth year with the 2017 class. Read More
Citrus
April 21, 2017
Alliance Stepping Up Efforts to Protect …
The Specialty Crop Farm Bill Alliance has kicked off its efforts to communicate to Congress its priority needs for the Read More
Apples & Pears
April 21, 2017
Interpera Congress Heads to Pacific Nort…
International pear conference comes to the U.S. for the first time. Read More
Grapes
April 20, 2017
Would You Be Willing to Pay More for Org…
While consumers might be ready to fork over more for organic produce, study says the feeling isn't quite the same when it comes to the adult beverage. Read More
Crop Protection
April 20, 2017
Beetle Battle Burgeoning for South Flori…
Scientists identify more species of pests that vector deadly fungus. Read More
Citrus
April 20, 2017
Farm Labor Is in Crisis
To have a great crop potentially rot in the field because workers can’t be sourced is probably worse than a weather event taking out production. Read More
Vegetables
April 19, 2017
Free Forum to Hail Florida Muck Farming …
Zellwood Historical Society helping shine a light on an industry that defined the area. Read More
Vegetables
April 19, 2017
Want Low Drama Food Safety Inspections? …
When I was in high school, my mom was the administrator of an outpatient hospital. Like all hospitals, Mom’s was Read More
Vegetables
April 19, 2017
Which Vegetable Crops Are the Most Popul…
The editors at American Vegetable Grower asked growers about their crops as part of our 2017 State of the Vegetable Industry survey, and gained a lot of insight into which crops are most commonly grown, and how well those crops are performing. Read More
Grapes
April 19, 2017
Donnell Brown Named President of Nationa…
New president brings experience in wine industry communications. Read More
Cucurbits
April 19, 2017
Alternaria Leaf Spot Awareness Can Save …
Learn how to identify, the survival and spread, as well as management methods for this malady. Read More
Apples & Pears
April 19, 2017
Young Apple Growers Meet with Lawmakers
Apple leaders from across the country discuss ag issues such as labor, trade, and research. Read More
Citrus
April 18, 2017
Florida Growers Seeking Inspiration Need…
The firsthand experience of speaking with farmers and actually seeing all the hard work, knowledge, ingenuity, and people behind where our food comes from is invaluable. Read More
Citrus
April 18, 2017
Citrus Growth Path Uncertain as Florida …
According to the latest Lay of the Land Market Report, the waiting game for a solution to greening has tempered groves sales. Read More
Farm Management
April 18, 2017
Survey Says New York Growers Lost More t…
Growers say they suffered more than 50% crop losses in Western New York. Read More