Biological value

Biological significance of a protein in a food is a measure of the efficiency with which this dietary protein can be converted into the body's own protein. The more similar the dietary protein is a protein body in its amino acid composition, the less food proteins are needed to reach equilibrium, a protein ( protein balance = 0, protein synthesis protein degradation = ). Of particular importance is to the content of essential amino acids. The reference value is used whole egg, whose biological value was arbitrarily set to 100 or 1 ( 100 %), as it was the protein at that time, for which the highest biological value was adopted. The concept of biological value was derived from the German nutritionist Karl Thomas (1883-1969) developed at the suggestion of Max Rubner.

Definition

If a food protein recovered better than egg protein from the body, it has a biological value with a value above 100, which is in contrast to a protein worse than egg protein used by the body, the biological significance of this protein is less than 100, the higher the biological value of a food protein is, the lower the required amount. To meet the protein requirements with proteins from whole egg, for example, a minimum daily amount of 0.5 g per kilogram of lean body weight is required. With increasing biological value required for the protein equilibrium supply decreases; for example at 136 to 65% potato ( protein) with 35% egg ( protein) to less than 0.4 g / kg.

By cleverly combining foods can be a relatively low biological value to a high biological value meal, since the amino acid compositions of the proteins complement each other and thus it comes to an appreciation. Many traditional food combinations lead to a supplementary effect (see combination examples). Animal protein is usually better than recycled vegetable protein because its amino acid composition of the amino acid composition of endogenous protein is similar.

High quality is not automatically be equated with " valuable " or "full " because the health value of a food is determined by many other factors such as the content of vitamins, minerals, nature and quantity of fats contained, carbohydrates, fiber, phytochemicals, exposure to anthropogenic toxins ( eg pesticides, see Organic Farming ) and Others m. The adjective "high quality " is used to express that a lower mass is needed in protein, to meet the protein needs of the body.

Examples

Examples of combinations

Other examples of combination in which the biological value is substantially increased:

• Aspic meat
• Legumes, meat or meat products
• Bread Meat
• Bean - corn (important for the optimization of the most low-protein diet in developing countries)

Incomplete proteins

Protein sources that do not contain all the essential amino acids are called " incomplete protein " and have a biological value of 0 through an appropriate combination with other protein sources, the quality - as already described further above - but are significantly increased.