Protein efficiency ratio (PER), net protein utilization (NPU), nitrogen digestibility (ND), organ weights, and amino acid composition were investigated for rapeseed protein isolates (RPI) prepared by alkaline countercurrent extraction and isoelectric precipitation of defatted rapeseed meal (DRM).
The PER values for 3 kinds of RPI obtained at pI of 6.7, 5.6 and 5.0 were 2.8, 3.1 and 2.9, and for DRM 2.5 while the NPU values for these RPI appeared to be 68, 73 and 71 %, and for DRM 56 %, respectively. Mean ND (85%), food intake (87), and weight gain (37.6) for RPI were significantly different from those of DRM (71 %, 77, and 28, respectively). There was no signicant difference in the PER among three RPI and casein (3.0), nor in the NPU among those proteins and casein (74%).
These data attributed to the favorable amino acid patterns of proteins isolated which contained balanced essential amino acids in proportions which meet the requirements of human adult(FAO/WHO, 1973).
|