Biomechanical indices of the bones of rats fed diets containing permeates and whey obtained during the production of cottage cheeses

摘要

Model studies were conducted on rats fed diets containing permeates and whey, in order to determine their bone strength on the basis of biomechanical indices. The experimental materials were acid-rennet whey (ARW), acid-rennet permeate (ARP) and acidpermeate (AP), obtained during the production of cottage cheeses. Whey and ultrafiltration permeates are valuable sources of some mineral elements, especially calcium and phosphorus. Particular attention should be paid to a favourable ratio between theseelements in by-products obtained during the production of cottage cheeses. The highest fragility of thigh bones was recorded in rats fed a diet in which the source of calcium was AP-lyophilisate. The bones of rats receiving diets with ARW and ARP showedhigher resistance in shear tests and more shear force was required for their fracture. The suitability of biomechanical indices of bone strength for the analysis of calcium utilization by the organism requires further research into the correlations between these indices and those obtained in balance experiments, i.e. absorption and apparent retention of this mineral element.