Investigation of the effect of trisodium-citrate on blood coagulation by viscometric approach

Blood coagulation is a process, which is initiated by certain physico-chemical effects. This process results in a change in the blood from the sol state, that is well suited for further processing, to gel state. 13 blood clotting factors take part in the cascade system of blood coagulation. Trisodium-citrate affects factor IV, the calcium, and prevents the change in blood texture. The effect of different concentrations of trisodium-citrate (0, 0.48, 2.4, 4.8, 9.6, 14.4, 19.2, 24 w/w%) on the texture of blood is investigated. Porcine blood was collected in 20 cm3 test tubes in a slaughterhouse directly before trisodium-citrate addition and was stored for one day under refrigerated conditions. The samples without trisodium-citrate coagulated and the samples with high trisodium-citrate (4–5 g) became solid as well because of the protein salting-out. The viscosity of successfully treated samples and the shear stress were measured with a rotational viscometer (Physica MCR 51, Anton-Paar) with concentric cylinders and Couette type method. The flow behavior of all samples could be described by the Herschel-Bulkley model. The yield point, the consistency index and the power of law index, which are determined by the equation of the model, showed that the samples with lower trisodium-citrate content coagulated “better” and the sample with high trisodium-citrate were most similar to Newtonian fluid. The results are trend-likes, but significant differences may be expected in the case of higher sample amount. The yield point of the sample, which contained 14.4 w/w% trisodium-citrate, was by 37.3% less than the sample containing 0.48% trisodium-citrate, and the consistency index of the sample with 3 g trisodium-citrate was by 20.5% higher than that of the sample with 0.48% trisodium-citrate. Thanks to these results a cheaper concentration and drying of porcine blood and blood fractions are available because no surplus water is added to the blood.