Characterisation of Nanoestructured Potato Starch Powders with Blackberry (Rubus fruticosus Var. Brazos) Juice

Potato starch has been used in the protection of antioxidants, but its use is limited due to its physicochemical properties. The objective of this work was to evaluate the effect of physical modification of potato starch by gelatinization, spray-freezing on liquid nitrogen and freezing in liquid nitrogen on the physicochemical properties and stability of powders added with blackberry juice. Frozen potato starch with liquid nitrogen exhibited higher colour retention and anthocyanins during processing, as well as adequate physicochemical and flow properties. While the spray-frozen starch on liquid nitrogen had a higher retention of anthocyanins, polyphenols and antioxidant activity during storage under controlled conditions. Atomic force microscopy revealed the modification in the microstructure of the developed powders. These results demonstrated that the microstructure of the powders was modified by conferring changes in the water adsorption capacity affecting their physicochemical properties and their stability during storage.