[Interaction of fluoride with milk constituents]

Fluoride concentrations have been studied in cow milk stemming from regions variably influenced by fluorine pollution. It was disclosed that fluoride concentration in the milk of cows grazing on areas with a high degree of environmental contamination by fluorine compounds was about three-fold higher as compared to the control group. Fluoride distribution was evaluated in milk, in which the protein sediment got separated from the whey. The said distribution was found to be equal in both of the milk constituents. Due to the decomposition of whey into the whey proteins sediment and the remaining solution, an answer was obtained to the question of which part of whey fluoride appeared in the ionized form (80%). Studying the binding of fluoride by isolating and purifying the fraction of milk proteins at various pH, it was revealed that alpha-lactalbumin bound fluoride at 3.9 pH. Because of limited caseins solubility at that pH, there was no possibility to find out whether they bound fluoride ions. At fresh milk pH, the caseins exist in the anionic form and as such they are unable to bind fluoride independently. The binding of fluoride with milk lipids was investigated and it was ascertained that about 11% of fluoride being introduced into milk were bound to lipid constituent. The study covered also the influence of fluoride ions on the magnitude of the optic polarization angle of aqueous lactose solutions in different concentrations. That angle undergoes diminution in comparison with solutions not polluted by fluoride. Fluoride concentration was defined in some milk formulas of Polish production designed for infants. They exceed, depending on the kind of formulas, 20-70 fold the average fluoride concentration evidenced in human milk. Thus, the differences in fluoride supplied to infants, fed by breast and artificially, are very great.