Environmental Engineering Reference
In-Depth Information
Feed hungry people
Food product donations avoid the generation of waste and help to feed the disadvantaged. At
the same time, it reduces the disposal costs and provides tax benefit to the donors. Typical
donors are food processors, distributors, retailers, wholesalers, and food service companies.
Usual food products that are donated include close-to-expiration products, off-specification
items, seasonal items, outdated but not spoiled food, promotional items, discontinued prod-
ucts, production overruns, and ingredients and raw materials (“Food Waste, n.d.).
In the United States, almost 1 million tons of groceries a year are donated to 200 food
banks across the country through the largest hunger relief program “Feeding America”
(“Expiring groceries get a second life,” 2008). Potential donors, who are concerned about
lawsuits from consumption of spoiled food, even when the spoilage happens after the food
leaves the donor's facility, are protected by the Good Samaritan Food Donation Act, which
was enacted in 1996 (Clinton, 1996).
Feed animals
Many by-products from the food industry have been processed and used as animal feed for
decades. Examples are the protein and fatty tissue from the fish, meat, and poultry industries
that are rendered and converted into meals and fat and spent grains from breweries and the
manufacturing of malt beverages.
The use of other by-products and residues is not as standardized as the two examples previ-
ously mentioned, but many of these by-products have nutritional value for animal feed. During
sorting and processing of fruits and vegetables, solid organic waste material is generated in the
form of off-grades, skins, stems, pomace, husks, cobs, and trims, which can be used to feed
cattle and swine. Likewise, produce that get spoiled during distribution and retailing can also
be used to feed farm and zoo animals. In most cases, farmers are willing to haul the waste
material from the premises at no charge.
The foodservice sector—including hospitals, amusement parks, cruise ships, nursing
homes, military installations, prisons, restaurants schools, and universities—produces food
wastes in the form of kitchen residues and food scraps with high nutritional value for animal
feeding, particularly swine. Feeding animals with food scraps is an established practice around
the world. However, the concern of spreading the highly transmissible foot-and-mouth disease,
a virus that attacks bovines, swine, sheep, and goats, has raised awareness about the issue, and
food scraps have been banned as animal feed in many places around the world. Therefore,
before feeding animals with food scraps, regulations need to be consulted. Many states in the
United States do not allow feeding food scraps to farm animals; other do allow it, but they
require the thermal treatment of the scraps before feeding, especially when there is meat pre-
sent. In other cases, “dry feed,” which consist only of bread, fruits, and vegetables is allowed.
Industrial uses
Brown and yellow grease
Waste vegetable frying oils (yellow grease) and grease from grease
traps (brown grease) could be used as substitutes for virgin feedstocks in the production of
biodiesel, but they both have the shortcoming of high content of free fatty acids (FFAs) and
moisture. In yellow grease, the FFA content can range from 4 to 15 percent and in brown
grease can go all the way to 100 percent (Tyson, 2002). The traditional biodiesel production
method converts feedstocks into biodiesel by esterification of triglycerides with methanol
under the presence of an alkali as catalyzer. This method needs low concentration of FFAs and
low moisture in the feedstock, otherwise large amounts of soap are produced instead of fatty
acid methyl esters.
