Beef tallow fatty acid composition

It is claimed by some laboratories that they can identify the absence of pork fat in, for example, beef tallow, by the determination of the simple fatty acid composition with a rough comparison of fatty acid compositions. Certainly the accepted ranges for lard and edible tallows (including premier jus) given in Codex Alimentarius are different (Table 5.2.), and pure fats can often be differentiated in this way, but the natural variability of the product ensures that this is not certain when lower levels of pork fat (<50%) are present. In the... 

Table 5.2 Acceptable ranges of fatty acid composition for pork fat (lard) and beef fat (beef tallow and premier jus) given in Codex Alimentarius (Codex Alimentarius Commission, 1993a,b,c)...

Adulteration of fats and oils is another matter of concern, which might occur accidentally or deliberately. Rendering of pork fat and beef tallow in the same equipment without proper washing is an example of accidental and unintended con-tamination/adulturation. However, often cheaper oils have been sold in place of, or mixed with, more expressive oils. Thus, before to the recognition of health benefits of hazelnut oil, this oil was an adulterant in ohve oil (10). As mentioned earher, different oils have considerably different sterol compositions. Thus, sterols could be a means of identifying adulterants because often fatty acid compositions of the adulterant and the original oils are similar (11-13). 

Fig. 10. Fatty acid composition of dietary vegetable oils and beef tallow. The values shown represent typical compositions of varieties grown commercially. Lines modified substantially through breeding or genetic engineering are available for soybean, canola, com, and sunflower.

Edible beef tallow (premier jus) is obtained by rendering approved edible stock and frequently does not require further refining (free fatty acid 0.3%). The USDA exerts very close control on the processing and transport of edible tallow. Recent specifications for different grades of tallow are given in Tables 3.173 and 3.174. The fatty acid compositions of beef tallow are given in Table 3.164. 

The unpleasant odor adhering to sheep tallow is difficult to remove, hence it is not used as an edible fat. Sheep tallow is harder and more brittle or friable than beef tallow. The fatty acid composition of sheep tallow is presented in Table 14.3. 

Mutton tallow (->sheep) is used in the same areas as beef tallow but only for industrial applications. Superior-quality grades are similar to beef - tallow. The fatty acid composition is also similar to beef - tallow. However, it contains a relatively high amount (4%) of odd-numbered, branched and trans fatty acids. 

The compositions of many animal tallows are superficially very similar to that of beef. Mutton tallow is normally slightly more saturated and therefore harder than beef tallow. Goat tallow is even harder. Some typical fatty add compositions are given in Table 3.163. As with with beef tallow, many of these fats contain significant amounts of trans and branched-chain fatty acids. 

What is it that makes some triglycerides solids (fats) and others liquids (oils) The distinction is clear from their composition. Oils contain a much higher percentage of unsaturated fatty acids than do fats. For example, most vegetable oils (such as corn oil or soybean oil) give about 80% unsaturated acids on hydrolysis. For fats (such as beef tallow), the figure is much lower, just a little over 50%. 

Fats can be hard and brittle substances (cocoa butter), hard substance (beef tallow), gooey soHds (pork lard, pahn oil) and viscous Hquids (vegetable oils). The melting and soHdihcation points of some fats are Hsted in Table 3.27. The range of values is mainly related to the variabihty of the composition of fatty acids and triacylglycerols. 

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