Lean meats

Economics. Estimates of anaboHc steroids in growing cattle indicate that savings associated with reduced feed costs are approximately 50.00 per animal. Increased value of the carcass resulting from the increased amount of saleable lean meat produced is estimated to range from 15.00 to 30.00 per animal. 

As a coen2yme component in tissue oxidation—reduction and respiration, riboflavin is distributed in some degree in virtually aU naturally occurring foods. Liver, heart, kidney, milk, eggs, lean meats, malted barley, and fresh leafy vegetables are particularly good sources of riboflavin (see Table 1). It does not seem to have long stabiUty in food products (8). 

Some of these compounds could be considered as dietary additives, but various other terms, including pesticides, can also be used. They can have beneficial effects on the environment and this aspect will be discussed later. The ionophore monensin, which is an alicyclic polyether (Figure 1), is a secondary metabolite of Streptomyces and aids the prevention of coccidiosis in poultry. Monensin is used as a growth promoter in cattle and also to decrease methane production, but it is toxic to equine animals. " Its ability to act as an ionophore is dependent on its cyclic chelating effect on metal ions. ° The hormones bovine somatotropin (BST) and porcine somatotropin (PST), both of which are polypeptides, occur naturally in lactating cattle and pigs, respectively, but can also be produced synthetically using recombinant DNA methods and administered to such animals in order to increase milk yields and lean meat production. "... 

Protein is an important component of most foods. Nearly everything we eat contains at least a small amount of protein. Lean meats and vegetables such as peas and beans are particularly rich in protein. In our digestive system, proteins are broken down into small molecules called a-amino acids. These molecules can then be reassembled in cells to form other proteins required by the body. 

The lipid in muscle is composed primarily of triglycerides (depot fats) and of phospholipids (membrane components), and is a constituent which varies enormously not only in amount present, but also in properties such as degree of saturation (species dependent). The ash of lean meat is comprised of various minerals such as phosphorus, potassium, sodium, magnesium, calcium, iron and zinc Carbohydrate was not noted in the proximate composition because while some may be present, it is normally there in low concentration compared to the other constituents. Glycogen is the carbohydrate occurring in greatest concentration in muscle but is normally degraded soon after the animal is sacrificed. 

In general, genotypes used in conventional production are characterised by a high capacity for protein accretion. This is achieved by crossbreeding different strains, mostly belonging to the Landrace, Large White, Duroc, and/or Hampshire breeds. Additionally, boars of the Pietrain breed are used to sire because of their famous effect on lean meat percentage. 

Schiitte A, Bork A, Mergens U, Pott U and Venthen S (1996), MHS-genetic, lean meat content and findings in lungs - the dominant factors in relation to meat quality , Landbauforschung Volkenrode, 166, 229-238. 

Soy Protein Concentrates. Both non-functional (low or no solubility) and functional (good solubility, emulsification capacity, and dispersibility) soy protein concentrates (70% protein, dry basis) are commercially available for use in meat products (2-4, 6, j), 15) Normally, a highly functional product with no harsh or bitter flavors is desirable. When used to replace lean meat, non-hydrated concentrate can be used at levels up to 6-7% in finished nonspecific emulsion meats Higher replacement levels or formulas with specific cost/nutrition requirements may use soy protein concentrate with a judicious amount of textured soy protein (6). Excellent yields, cost savings, texture, flavor and nutrient profiles are possible. However, most soy protein concentrates lack sufficient solubility or sufficiently low viscosities to be used in brines for absorption or injection into whole muscle tissue. When legal standards for protein content exist (13), more concentrate must be used to achieve legal minimums. Brine viscosities increase and uniform distribution of brine components throughout the specific whole muscle piece is restricted. Finished product appearance and flavor are easily compromised. Thus, use of soy protein concentrates in whole muscle applications is limited. 

This subject is discussed in Chapter 15, but a brief summary is given here, as an introduction to fat metabolism. The three major components of a human diet are meat, fish and plants, and the fats associated with each component can be different. Meat usually comprises the muscle of mammals and birds but it is always associated with fat. Even apparently lean meat may have a high fat content a 250 g beef steak may contain 60 g fat in addition to its 80 g protein. Some of this will be adipose tissue between muscles the remainder is triacylglycerol (TAG) within the fibre. In addition, milk and other dairy products contain significant amounts of fat about a quarter of the fat in the average UK diet comes from dairy produce. 

Nicotinic acid (niacin) Liver, lean meats, cereals, legumes Energy metabolism... 

It has long been established that the sexual status of an animal controls and coordinates its growth rate and speed of fattening. Bulls grow faster and lay down more lean meat in the carcass than steers, whereas steers grow faster with a higher feed conversion efficiency than cows. These beneficial effects on animal performance are due to the sex steroids produced in the testes. 

Niacin is found in unrefined and enriched grains and cereal, milk, aid lean meats, especially liver. Limited quantities of niacin can also be obtained from the metabolism of tryptophan. [Note The pathway is inefficient in that only about 1 mg of nicotinic acid is formed from 60 mg of tryptophan. Further, tryptophan is metabolized to niacin orty when there is a relative abundance of the amino acid—that is, alter the needs for protein synthesis and energy production have been met]... 

Meat, as defined above vanes widely in composition, not merely with the individual animal yielding it, but also according to the breed, age, etc, of the animal, to the part of the body from which it is obtained, and to the method of slaughtenng employed The total nitrogenous substances are mostly about 20%, and the fat and water vary together, the one increasing as the other diminishes, for instance, fat beef with 32-50% of water may contain 55-1% of fat, while lean meat with 74 20% of water may contain only 3 45% of fat. 

Meat extracts are more or less concentrated aqueous extracts of muscular flesh freed from coagulable albuminoid substances. They contain, therefore, in a more or less reduced volume, all the water-soluble principles of lean meat, and they have the appearance of a stiff, reddish-brown mass, with a rather bitter taste and a peculiar, not unpleasant odour Liebig s extract type). 

Choose lean meats and skinless poultry and trim away any visible fat before cooking. Fish and other sea foods are very low in fat and provide some beneficial fatty acids for a healthy heart. 

Most lean meats such as round and flank beef steak, fish, lamb, and pork, supply 6-7 G of complete protein per ounce. A 200 LB bodybuilder consuming 2G of protein per pound of bodyweight daily would therefore need to eat about 4 pounds of lean meats daily. Wow That is a lot of chewing and a nice chunk of change. Enter protein powders. 

In a series of investigations (10-19) it was definitely established that the extraction of minced, lean meat (beef, pork, and lamb) with... 

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