Inedible fats

New oilseed crops, currently studied as potential sources of specialty fatty acids, include Crambe abyssinica for erucic acid, Limnanthes alba for very long-chain fatty acids, Dimorphotheca pluvialis for dimor-phecolic acid, Lesquerella fendleri for les-querolic acid, Calendula officinalis for calendic acid, and Euphorbia lagascae and various Vernonia species for vernolic acid.194 The lowest cost sources (inedible fats and oils and palm oil fractions) are likely most likely to be exhausted first as world trade in industrial applications grows. Cornstarch is becoming a major feedstock for plastics production. This may compete with potential oil uses, but also will increase production of com oil. 

In the United States, inedible fats are called tallows if, after saponification in the American Oil Chemists Society s titer test (AOCS Cc 12-59), solidification occurs above 40°C (104°F), and greases if solidification occurs below this temperature (1). The demarcation temperature varies among countries and 38°C (100.4°F) is used by some. Throughout this chapter, the term tallow refers to both tallows and greases, which also may contain vegetable oUs, recycled by renderers. 

Approximately 4.1 million MT of inedible animal fats are rendered in the United States annually (Table 1). The major sources, in order of decreasing tonnage, are beef packing, pork packing, spent restaurant fats, and broiler and turkey processing. Only about 5% of the total supply of inedible fat is recovered from dead stock (1). 

The largest use for inedible fats worldwide is in animal feeds. Domestic use in various feeds is shown in Table 2. Approximately 56.2% is used in broiler and turkey feeds, and another 2.7% in feeding poultry layers (29). It has been estimated... 

Inedible fats, oils, grease and tallow. Hearings, Eightieth Congress, 1948. 

USE As an additive to edible or inedible fats or oils, hydrocarbon fuels or luhricants, retards oxidation Or metal contamination Thompson, U.S. pat. 2,770,545 (1956 to Universal Oil Prod.). 

These concepts are realized to a greater extent in composites based on thermoplastic polymers incorporating low-molecular plasticizing liquids and Cl [119-121]. Compositions based on HDPE, mineral oil MS-20 (MO) and oil-soluble Cl of metals, e.g. GRM (tar of vegetable oils and inedible fats),... 

Lard produced by wet rendering is known as prime steam lard . Neats foot oil is a low-melting inedible fat... 

Animal by-products, condemned carcasses and parts from packing plants, trimmings and bones from butcher shops, spent frying fats/oils, and fats collected from restaurant and food service kitchen grease traps are dry-rendered to produce inedible fats and oils. 

Colourless liquid. B.p. 286 C/100 mm., insoluble in water. Oleic acid occurs naturally in larger quantities than any other fatty acid, being present as glycerides in most fats and oils. It forms one third of the total fatty acids of cow s milk. A crude grade from inedible tallow is used in the production of lubricants, detergents, resins and other products. 

In the United States, more than 16.3 x 10 kg of human-inedible raw materials are available each year, and the rendering industry is a valuable asset in diverting these into valuable ingredients for use primarily in animal foods (4). The three largest meat packers are responsible for nearly four-fifths of aU red meat production (5) and enormous amounts of rendered meat meal and animal fat. Three broiler producers account for about 40% of the total broiler production. American Proteins, Inc. (RosweU, Georgia), the world s largest processor of poultry by-products, produces more than 450,000 t of poultry meal, feather meal, and poultry fat each year. It also produces more than 100,000 t of fish meal, fish oil, and fish products each year. Pish meal production worldwide in 1986 was estimated at 6.23 x 10 t, which with the 125 x 10 t of meat and bone meal plus 6.67 x 10 t of feather meal and poultry by-product meal (6) is the primary source of animal proteins used by the pet food industry. 

Hydrogenation is a chemical process where liquid oils are converted to solid fats. In this process, hydrogen is added to oils in the presence of a catalyst. Inedible oils or less useful oils are converted to edible, hard fats by this process. For example, cotton oil is treated with hydrogen at about 500°C in the presence of a catalyst. The resultant hard fat is used for cooking. 

Rendered beef, pork, poultry, and other animal fats are not well reported internationally, and global statistics are unreliable. Total production of fats in the United States by the rendering industry for 2000 is estimated at 4.18 million metric tons.68 Outputs of all rendering facilities captive to integrated broiler operations might not be included. Of the amount reported, 76 percent is inedible tallows and greases, 18 percent is edible beef or mutton tallows, and 6 percent is edible pork lard. 

Rendering produced an estimated 4.18 million metric tons of animal fats was produced in the United States in 2000 by rendering.87 Of this amount, approximately 18 percent and 6 percent were edible tallow and lard, respectively, and 41 percent and 35 percent were inedible tallow and grease. Approximately 15 percent and 34 percent of the edible tallow and lard, respectively, and 37 percent of the inedible tallow and grease were exported. Of the inedible tallow and grease used in the United States, an estimated 75 percent was used as animal feed, 16 percent was converted to fatty acids by the oleochemicals industry, 4 percent was used in soaps, and 3 percent in lubricants. Inedible animal fats are the lowest cost domestic fat sources. Their market price per pound sometimes is less than fuel oil, and rendering plants have chosen to bum them as fuels. In 2001, animal fats were included with vegetable oils for federally supported trials of biodiesel fuel. 

Domestically, methyl esters are made from soybean oil, spent frying oils, and inedible animal fats. Palm oil is used in Southeast Asia, and rapeseed in Europe. Although appreciable in quantity, supplies of such materials actually are small compared with the amount of TAG that would be required if significant quantities of methyl esters were used in fuels. Governmental support of biodiesel development has included funding of research and demonstration projects, and reducing or eliminating state or federal taxes collected for its fuel use. In turn, this funds the amount of methyl esters that can be... 

Furthermore, unsaturated oils are more susceptible than saturated fats to oxidation at the allylic carbon atoms— the carbons adjacent to the double bond carbons—a process discussed in Chapter 15. Oxidation makes the oil rancid and inedible. Hydrogenating the double bonds reduces the number of allylic carbons (also illustrated in Figure 12.4), thus reducing the likelihood of oxidation and increasing the shelf life of the food product. This process reflects a delicate balance between providing consumers with healthier food products, while maximizing shelf life to prevent spoilage. 

Grease production data are often lumped with that for inedible tallow. Greases constitute about 45% of this total and are used exclusively in nonedible applications. In the United States, the use of yellow grease in animal feeds is increasing yearly and in 2000 accounted for 36% of total feed fat usage (62). 

Pounds of oil production are a 3-year average (1993-1995) from OH Crops Yearbook, October 1997, USDA, ERS with the followihg exceptions rapeseed was calculated by multiplying oil per acre times the 1993-95 average humber of acres harvested. Number of harvested acres comes from USDA, NASS, January 1996. Inedible tallow and yellow grease supply comes from US. Department of Commerce, Bureau of the Census, Fats and Oils, Production, Consumption and Stocks, Annuai Summaries 1993-1995. 

Most deliveries of feeding fats are made by insulated tank truck, which allows users without raihoad sidings to be serviced, just-in-time deliveries, reduced numbers of local storage tanks, and rapid delivery while the fat remains hot. The industry and its contract haulers take pride in their equipment, and an inedible tallow tank truck looks little different from other milk or liquid ingredients trucks if kept clean. 

Dust Control. The use of soybean oil (100, 101) and inedible animal fats (102) to reduce dustiness in swine feeding operations, especially during months of low... 

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