Biological Value

Biological Value, or BV, is a numeric representation of the usefulness of protein found in foods. Formulated by the scientific community, the BV helps distinguish protein content from useable protein by evaluating the amount of food protein that is resynthesised into the body's cellular proteins. The amount is determined by calculating the nitrogen used for tissue formation divided by the nitrogen absorbed from food. This is then multiplied by 100 and expressed as a percentage of nitrogen utilised.

 

The base level of utilisation is the whole egg, which is given a BV of 100. All other proteins are compared to the whole egg and given a BV of either greater or lesser than 100 depending on how they are utilised by the body as compared to the whole egg protein.

 

There are, however, some inherent problems with this rating system. BV does not take into consideration several key factors that influence the digestion of protein and interaction with other foods before absorption. BV also measures a protein's maximal potential quality and not its estimate at requirement levels.

 

The protein rating adopted by the scientific community as the preferred scoring method is PDCAAS.