Study of antioxidant activity of fermented milk products enriched with selenium-containing nanosized system

Nanosized selenium was synthesized by chemical reduction in an aqueous medium using ascorbic acid; the following substances served as stabilizers for selenium nanoparticles: sodium laureth sulfate, hydroxyethyl cellulose (B30K), catamine AB, bovine serum albumin, didecyldimethylammonium chloride, cocamidopropyl betaine, tween 80, methylcellulose (MC 100), and chitosan. The product was enriched at the rate of 30% of the daily dose of the essential microelement selenium per 1 liter of fermented milk product. The following physicochemical properties were measured for the test samples: active acidity of the medium and titratable acidity of the medium. Based on the data obtained, it is evident that the studied parameters differed slightly from the characteristics of the control sample. The active acidity of the fermented milk product medium with the addition of nanoparticles varied from 3.98 to 4.08, titratable acidity was in the range of 103–112 оТ with the control sample indicator of 116 оТ. Analysis of the obtained data showed that the antioxidant activity of the obtained fermented milk products is similar to the control and is at the level of 0.25 mg TE/ml, with the exception of samples enriched with nanosized selenium stabilized by surfactants — cocamidopropyl betaine and tween 80. These products had increased antioxidant activity, which was higher than the others by up to 20%. Thus, enrichment of fermented milk products with selenium nanoparticles can contribute to an increase in the antioxidant activity of the product without affecting its physicochemical parameters and quality characteristics.