Selenium nanoparticles stabilized with Tween 80: Synthesis, characterization, and application in fortified milk and fermented dairy products

This study presents the synthesis selenium nanoparticles (SeNPs), stabilized with Tween-80 (Tw) for potential fortification of milk and fermented dairy products. SeNPs were prepared by chemical reduction with ascorbic acid in an aqueous medium. Optimal synthesis parameters were obtained using neural network optimization. Quantum chemical modeling showed that the Se-Tw interaction is an energetically favorable process (∆E < −80 kcal/mol), and the Se-Tw molecular complex is chemically stable (η = 0.078 eV). In turn, the stability of SeNPs was tested by forming solutions with different pH and ionic strength values. It was found that SeNPs stabilized with Tw (SeNPs-Tw) have a negligible effect on the physicochemical parameters of the dispersed phase of milk. A slight increase in titrated acidity by 1–3 °T and a decrease in pH by 0.05–0.12 were detected in experimental milk samples. during 21-days storage. Surprisingly, addition of SeNPs increased the average hydrodynamic radius of disperse composition of milk with 1.5, 2.5 and 3.2 % fat from 24 to 27 nm to 37–38 nm. It is worth noting that titratable acidity increased smoothly in all presented samples and to 120 ± 10 °T, which is in the required range for fermented dairy products. Interestingly, SeNPs-Tw had a stimulating effect on the growth of lactic acid bacteria. Thus, the number of L. acidophilus was higher in the experimental sample with a maximum at SeNPs-Tw concentration equivalent to 30 % of Se recommended daily allowance. Consequently, functional fermented milk products fortified with SeNPs-Tw can potentially become a solution to the problem of a colossal Se deficiency.