Meta Search Engine Navigation


Look For It  




Protein Quality Evaluation Methods



by Robert Baird

ARTICLE REPRINTING IS PERMITTED

Biological Value (%) is calculated as retained nitrogen/ absorbed nitrogen X 100. To illustrate how this provides an evaluation of protein quality, consider a scenario in which all amino acids in a protein are used for protein synthesis. Here, retained and absorbed nitrogen would be equal and the biological value would equal 100%.

Conversely, if some indispensable amino acids are not available in the protein source, protein synthesis is impaired and some unused nitrogen is excreted from the body, Le., retained nitrogen decreases relative to absorbed and the biological value drops below 100%. Consequently, some foods such as complete protein foods (e.g., milk) have high biological values (95%), while incomplete protein foods are much lower (Le., corn [60%1). It is not possible to have a biological value > 1 00%. Net Protein Utilization is a similar measure but involves a direct measure of retained nitrogen, Le., destruction and analysis of the body, and therefore is only used with animal studies.

Protein Efficiency Ratio is determined as body mass gain/protein intake and, although a useful measure when used in growing animals, has little value for humans for two reasons. First, this method is not used in human experiments because, ethically, human subjects cannot be deprived of necessary nutrients. Second, the difference in species growth rates, Le., lower in humans versus rats, results in errors when animal data are used to estimate human needs. Protein Digestibility-Corrected Amino Acid Score is based on the amino acid content of a food corrected for digestibility. The score reflects the limiting indispensable amino acids (those amino acids that humans cannot synthesize) in a food. The reference value used is the requirement for a 2-5-year-old individual. This provides a built-in safety buffer because protein needs of this age group are greater than for adults.


Information About The Author

About information on bodybuilding & fitness . Also did you know about conditions & diseases and types of natural supplement .


Published by Meta Search Engine LOOK-4IT.COM.




You can reprint this article for FREE at your web site. Doing this you agree to keep all texts and hyperlinks unchanged.

Please keep reference to LOOK-4IT.COM meta search engine as well, if you decide to use this article as a free content for your web site.

Back to article category: Bodybuilding

Additional Bodybuilding Articles

Other Contributing Risk Factors for Health
Obesity is not conducive to increased longevity because it is a strain on the heart and a precursor for many of the modifiable risk factors that promote cardiovascular disease.

The Rules of Protein Consumption for Muscle Growth
The benefits of protein, and protein timing for optimal muscle growth.

Why you Need a Power Rack if you Plan to Lift Weights at Home
You must have a power rack if you want to gain mass from home!

Muscle Hypertrophy - What Every Bodybuilder Should Know About
Mucular Hypertrophy and why its important in Bodybuilding

MuscleTech Gakic: A new era in musclebuilding performance
This article describes about GAKIC a pre-workout muscle building supplement and what different chemicals are generated during our workout and how GAKIC can help us workout for longer periods and hence helping us to build our body-muscles without any negative impact.







Home  |  Submit Article  |  Link to Us  |  Directory  |  Free Content  |  Contact Us  |  Privacy Policy  |  Terms of Use

Copyright © 2005-2006, LOOK-4IT.COM. All rights reserved.

All trademarks, icons, and logos, shown or mentioned at this web site, are the property of their respective owners.
The information in the articles is provided without any warranty and must by used by the reader at their own discretion.
A professional opinion should be sought before taking any of the advice.