Digestible indispensable amino acid scores of nine cooked cereal grains

Br J Nutr. 2019 Jan;121(1):30-41. doi: 10.1017/S0007114518003033. Epub 2018 Nov 6.


True ileal digestibility (TID) values of amino acid (AA) obtained using growing rats are often used for the characterisation of protein quality in different foods and acquisition of digestible indispensable amino acid scores (DIAAS) in adult humans. Here, we conducted an experiment to determine the TID values of AA obtained from nine cooked cereal grains (brown rice, polished rice, buckwheat, oats, proso millet, foxtail millet, tartary buckwheat, adlay and whole wheat) fed to growing Sprague-Dawley male rats. All rats were fed a standard basal diet for 7 d and then received each diet for 7 d. Ileal contents were collected from the terminal 20 cm of ileum. Among the TID values obtained, whole wheat had the highest values (P<0·05), and polished rice, proso millet and tartary buckwheat had relatively low values. The TID indispensable AA concentrations in whole wheat were greater than those of brown rice or polished rice (P<0·05), and polished rice was the lowest total TID concentrations among the other cereal grains. The DIAAS was 68 for buckwheat, 47 for tartary buckwheat, 43 for oats, 42 for brown rice, 37 for polished rice, 20 for whole wheat, 13 for adlay, 10 for foxtail millet and 7 for proso millet. In this study, the TID values of the nine cooked cereal grains commonly consumed in China were used for the creation of a DIAAS database and thus gained public health outcomes.

Keywords: AA amino acid; AID apparent ileal digestibility; CP crude protein; DIAAS digestible indispensable amino acid score; PDCAAS protein digestibility-corrected amino acid score; TID true ileal digestibility; Cooked cereal grains; Digestible indispensable amino acid scores; Growing rats; Protein quality; True ileal digestibility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / metabolism*
  • Animals
  • China
  • Diet
  • Digestion*
  • Edible Grain / chemistry*
  • Fagopyrum / chemistry
  • Ileum / metabolism
  • Male
  • Millets / chemistry
  • Oryza / chemistry
  • Plant Proteins, Dietary / analysis
  • Rats
  • Rats, Sprague-Dawley
  • Triticum / chemistry


  • Amino Acids
  • Plant Proteins, Dietary