In vivo rat assay for true protein digestibility and protein quality of beef and meat products extended with soy protein

Int J Food Sci Nutr. 1997 Jan;48(1):51-6. doi: 10.3109/09637489709006963.


The protein quality of ten food products in including beef, bovine rumen and four meat products extended with soy proteins had been evaluated by rat feeding experiment; defatted freeze-dried whole egg served as a reference protein. Mean endogenous fecal and metabolic urinary nitrogen amounted to 1.01 and 1.11 mg/g food consumed, respectively. True protein digestibility and biological value of beef averaged 90.3% and 82.6%, respectively. The protein qualities of bovine rumen are quite similar to that of beef. Beef products extended with soy protein are quite inferior in their true protein digestibilities (81.4-84.6%) and biological value (68.8-76.0%) as compared to beef. The utilizable protein of extended meat fluctuated between 22.6-29.3% compared with a mean level of 70% in beef.

MeSH terms

  • Animals
  • Cattle
  • Dietary Proteins / metabolism*
  • Digestion*
  • Food, Formulated*
  • Male
  • Meat Products*
  • Meat*
  • Nutritive Value
  • Rats
  • Rats, Sprague-Dawley
  • Soybean Proteins*


  • Dietary Proteins
  • Soybean Proteins