Protein digestibility of alkali- and fructose-treated protein by rat true digestibility assay and by the immobilized digestive enzyme assay system

Hyo-Ihl Chang, George L. Catignani, Harold E. Swaisgood

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6 Citations (Scopus)


The effect of processing on the digestibility of various food proteins was examined by using the immobilized digestive enzyme assay (IDEA) system. The values obtained were compared to true digestibilities determined by rat bioassay. Sodium caseinate, egg white, soy protein, and whey were treated with either 0.2 N NaOH at 40°C for 6 h or 0.5 M fructose (pH 7.0) at 90°C for 4 h. Untreated proteins were also analyzed. Treatment of all samples (n = 12) with 4 M urea assured solubility. Regression analysis of data for all samples resulted in a correlation coefficient (r) of 0.83 (p < 0.001). The IDEA systems appears to be an accurate and reliable estimate of in vivo digestibilities. Furthermore, it offers a more rapid and less expensive alternative to animal bioassays.

Original languageEnglish
Pages (from-to)1016-1018
Number of pages3
JournalJournal of Agricultural and Food Chemistry
Issue number4
Publication statusPublished - 1990 Dec 1
Externally publishedYes


ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Food Science
  • Chemistry (miscellaneous)

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