Protein efficiency ratio is
Gain in weight / protein consumed
Product of digestibility coefficient and biological value divided by 100
Percentage of nitrogen retained out of nitrogen absorbed
Percentage of protein absorbed after digestion
A. i.e. (Gain in weight / Protein consumed) (702- Rana Shinde 7th) (512 - U. satyanarayan 3rd)1. PROTEIN EFFICIENCY RATIO (PER) - consists of feeding weaning (21 days old) albino rats with a 10% test protein diet and recording the gain in body weight for a period of 4 weeks.Gain in weight of young animals per unit weight ofprotein consumed**PER =Gain in body weight (g)Protein consumed (g)The PER for egg protein is 4.5 : for milk protein 3.0 for rice protein 2.22. BIOLOGICAL VALUE - defined % of absorbed nitrogen retained by bodyBV =Nitrogen retained-----------Nitrogen absorbedx 1003. NET - Protein Utilization (NPU) - defined % of food Nitrogen that is retained in the bodyNPU =Digestibility Cofficient x Biological valueProtein intake (gm)4. CHEMICAL SCORE - based on the chemical analysis of the protein for the composition of essential amino acids which is then compared with a reference protein (usually egg protein)Chemical score =mg of the limiting amino acid/g. test proteinmg. of the same amino acid/g.egg proteinx 100
Proteins and Amino Acids