BUFFER CAPACITY OF BIOLOGICALLY ACTIVE PRODUCTS FOR SPECIAL PHYSIOLOGICAL PURPOSES

Abstract

It is known that the buffering capacity of different milk types and biologically active products for special physiological purposes is important in the physiology of digestion. It has been established that the buffering capacity of products for infants is several times higher than that of mother’s milk, which reflects one of the reasons for the significant differences in the digestive process during artificial and natural feeding. To determine the optimal consumption of ionite in order to reduce the buffering capacity of milk in the production of biologically active products, including those intended for infants, a series of experiments was conducted under static and dynamic conditions. Anions are removed by contacting milk with Dowex-2 anionite in the OH--form. During desalination, the concentration of phosphate decreases by 30–50%. Furthermore, there is a decrease in the buffering effect in the pH range from 5.6 to 4.0, which corresponds to the optimum buffering effect not only of citrates and phosphates, but also of casein. Due to the fact that the removal of phosphate disrupts the equilibrium between soluble and bound colloidal phosphate, which leads to a decrease in the buffering effect of casein micelles. Thus, total reduction in buffering capacity after anionisation is 10%. The milk passed through the anionite undergoes cation exchange (cationite in the H+ -form). In milk treated with cationite, the calcium concentration decreased by 22%. Additionally, there is a decrease in the buffering effect in the pH range from 5.0 to 4.0, as well as up to pH 5.6. This is owing to a natural decrease in pH with the utilisation of cationite in the H+-form. At the same time, in the pH range from 5.6 to 5.0, the buffering effect of milk is partially restored. However, this increase is insignificant, and the resulting mixture of filtrates after double ion exchange has a buffer capacity of 16% less than the original milk. Consequently, the results of the studies showed that the decrease in the milk’s buffering capacity during its desalination owing to the removal of weak acid anions (citrates and phosphates), while the removal of cations is accompanied by an increase in the buffering effect in the pH range from 5.6 to 5.0, which corresponds to the optimal value of the casein buffering effect. The utilisation of ion exchange according to the scheme: anionite in the OH--form – cationite in the H+-form allows to reduce the buffering capacity of milk by 16%.