Essential amino acids EAA

Historically, elemental formulas designed for renal failure were enriched with essential amino acids (EAAs) and contained lesser amounts of nonessential amino acids (NEAAs) than standard formulas. Theoretically, EAAs could combine with urea nitrogen in the synthesis of NEAAs, thus leading to a decrease in blood urea nitrogen (BUN). The only situation in which such formulas may be appropriate is in patients with... 

The diet must provide those amino acids which the body cannot synthesize (essential amino acids, EAA) and nitrogen in the form of nonessential amino acids (NEA). Both EAA and NEA are required for biosynthesis of proteins and other nitrogen-containing compounds necessary for homeostasis or growth. Thus, the total nitrogen content of a specific food must be considered to be nutritionally significant. 

Amino acid composition is the principal effect. All proteins are made up of combinations of the 21 biological amino acids. Some of these can be synthesized or converted in the body, whereas others cannot and must be ingested in the diet. These are known as essential amino acids (EAAs), of which there are nine in humans. 

Percentage ratio of essential amino acids (EAA)/total amino acids (TAA). 

Another important nutritional item to be considered is the amino acid (AA) composition of the preys. Wlanueva et al. (2(X)4) found that lysine, arginine and leucine represented about half of the total essential amino acids (EAA) in paralarvae. More recently, Villanueva and Bustamante (2006) also studied the possible importance of essential elements such as copper in the diet. 

As is true for all essential amino acids (EAAs), the body s need for lysine increases during periods of intensive exercise training, and therefore it is genraally included in AA blends designed to maximize exerdse-induced protein synthesis (see Section 15.7.3.5). 

Protein hydrolysis in 6N HCl and subsequent analysis to determine amino acids (except tryptophan, which is acid labile) chemically present is a first step in protein quality evaluation. The chemical score and the EAA index represent attempts to use this information to chemically estimate nutritional quality of protein their obvious limitation is their disregard for amino acid availability. The chemical score is obtained by evaluating the percent of the limiting amino acid in comparison to that amino acid in whole egg protein ). The EAA index is the geometric mean of the ratios of each of the essential amino acids to those amino acids occurring in whole egg (4). 

AAA, aromatic amino acids (includes phenylalanine and tyrosine) BCAA, branched-chain amino acids (leucine, isoleucine, and valine) EAA, essential amino acids (leucine, isoleucine, valine, phenylalanine, tryptophan, methionine, threonine, and lysine) LCT, long-chain triglycerides MCT, medium-chain triglyceride. 

Organisms other than plants vary widely in their capacity to synthesize amino acids from metabolic intermediates and fixed nitrogen. For example, many microorganisms can produce all the amino acids they need. In contrast, animals can synthesize only about half the amino acids they require. The nonessential amino acids (NAA) are synthesized from readily available metabolites. The amino acids that must be provided in the diet to ensure proper nitrogen balance and adequate growth are referred to as essential amino adds (EAA). 

Dietary protein sources differ widely in their proportions of the EAA. In general, complete proteins (those containing sufficient quantities of EAA) are of animal origin (e.g., meat, milk, and eggs). Plant proteins often lack one or more EAA. For example, gliadin (wheat protein) has insufficient amounts of lysine, and zein (com protein) is low in both lysine and tryptophan. Because plant proteins differ in their amino acid compositions, plant foods can provide a high-quality source of essential amino acids only if they are eaten in appropriate combinations. One such combination includes beans (low in methionine) and cereal grains (low in lysine). 

Note-. AA = amino acid EAA = essential amino acids. Composition is based on a 70-kg person. Drink was given at 1 and 2 h after completion of exercise. 

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