Dairy powder enriched with a soy extract (Glycine max): Physicochemical and polyphenolic characteristics, physical and rehydration properties and multielement composition

This work presents the enrichment of powdered dairy compounds with soy extract, and the determination of its physical properties, rehydration characteristics, multielement profile, and polyphenolic potential. Five dairy compound formulations were developed, where milk powder was replaced by 10, 20, 30, 40, and 49 % w/w of soy extract.. Multivariate analyzes using combined PCA analyzes were used to group the samples and, thus, reveal the main characteristics associated with their physicochemical properties, bioactive composition, and multi-element profile. The protein content in the samples was not significantly affected by the addition of soy extract. There was a gradual increase in the total fat as the concentration of soy extract increased. Furthermore, with the increase in the percentage of soy extract in the dairy compounds, there was an increase in the levels of total polyphenols, total flavonols, and antioxidant capacity, and of some minerals, such as Fe, Mn, P, Cu, and Mg. The DC49 sample showed the highest values for total polyphenols (178.65 mg of gallic acid (GAE)/100 g) and total flavonols (1.51 mg of catechin/100 g). The addition of soy extract promoted the enrichment of important minerals in the samples, with an increase of up to 55 times in the Fe content and up to 40 times in the Mn content. Physical properties (density and fluidity) and rehydration properties (wetting, dispersibility, and solubility) also were affected as the percentage of soy extract in the samples increased. When there was an addition of up to 20 % soy extract, the samples are still wettable. All dairy compounds showed solubility above 69 %. The use of soy extract in the polyphenolic and mineral enrichment of the dairy compounds is important to add nutritional value to powdered milk, we emphasize that this product has enormous potential to be used in diets that require mineral supplementation.