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.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)