[Development and testing of protein mixtures based on blood and collagen]

[Evaluation of the quality of protein mixtures based on collagen and blood. Comparison of biological and chemical evaluation criteria in rats]

The quality of protein mixtures on the basis of blood protein, collagen, wool and other proteins was tested using different chemical and biological criteria of protein evaluation. Before mixing the single proteins were hydrolysed enzymatically by means of acid or alkaline proteinases. In this study the influence of both hydrolysis processes on the bioavailability of the protein mixtures was also considered. The N-balance experiments were carried out with weanling Sprague-Dawley rats in groups of n = 6 animals each. The estimated BV's showed that the protein quality was significantly affected by both hydrolysis procedures especially when the hydrolysates were compared with the non-hydrolysed protein components. The BV's also showed that the quality of all mixtures of protein hydrolysates was less than that of casein (reference protein) and the availability of the alkaline hydrolysed proteins better than that with acid proteinase treated proteins. This result could be confirmed by the calculated chemical criteria E/T- and E/N-ratios, EAA-Index and Arnould-Index. The results of the growth-criteria PER, NPR and RNV did neither correspond with each other nor they were of good agreement with N-balance based BV and NPU.