Soymilk stability increase using polyphenols microcapsules

Functional beverages have aroused a great interest to the food industry. Among the functional ingredients, there is a growing demand for antioxidant incorporation into foods, which implies a challenge to preserve their bioactivity. The health benefits provided by soymilk can be improved by the addition with microcapsules of polyphenols from peanut skin and this procedure is an alternative to protect these natural and bioactive compounds from environmental factors. The aim of this work was to determine the chemical, antioxidant, microbiological and sensory changes during storage of the product. Soymilk samples were prepared without any addition (C); with peanut skin extract (BEA); and with microcapsules with polyphenols (MCBEA) and stored at 4 °C for 30 days. Results showed that the addition of polyphenols (free or microencapsulated) improved the chemical, microbiological and sensory stability of soymilk. The BEA and MCBEA had lower values of hydroperoxides, hexanal, bacterial growth, oxidised flavour, and sweet taste than C. The BEA exhibited higher phenol content (819.72 mg gallic acid equivalents/L), antioxidant activity (64.66% DPPH inhibition) and colour intensity than MCBEA. The study suggested that polyphenol microencapsulation is a procedure that can protect these sensitive compounds and control their release into this food matrix.