In vitro assay for protein digestibility: interlaboratory study.

Journal - Association of Official Analytical Chemists

PubMedID: 2211487

McDonough FE, Sarwar G, Steinke FH, Slump P, Garcia S, Boisen S. In vitro assay for protein digestibility: interlaboratory study. J Assoc Off Anal Chem. 1990;73(4):622-5.
True protein digestibilities of 17 protein sources were estimated by 6 laboratories using an in vitro, 3-enzyme digestion system in a pH stat. Samples from animal, vegetable, and mixed food sources were freeze-dried (if not already dried), ground, mixed, and shipped to each collaborator along with a sodium caseinate standard and trypsin, chymotrypsin, and peptidase. The uptake of titrant during enzymatic digestion was used to calculate estimates of digestibility. Digestibilities ranged from 100% for casein to 89. 9% for whole wheat cereal. Mean relative standard deviations for repeatability were 1. 4% for rolled oats and less than 1% for the remaining 16 samples. Mean relative standard deviations for reproducibility ranged from 5. 0 to 0. 8%; values were less than 2. 5% for 13 of the 17 samples.