Effect of carriers on physicochemical properties, antioxidant activities and biological components of spray-dried purple sweet potato flours

Abstract

This work focuses on the impact of carriers on the physicochemical properties, antioxidant capacities and biological components of spray-dried purple sweet potato flours. The optimal carrier addition of maltodextrin (MD), β-cyclodextrin (β-CD) and their combination (MD/β-CD, 5/1) were 30, 10 and 24 g/100 g in terms of flour yield. Compared to the flour without carrier, flours with carriers had higher values in L*, fluidity, water solubility index, glass transition temperature, lower values in chroma, water absorption index and water holding capacity. The influence intensity of carriers on the physicochemical properties of flours followed the sequence of MD > MD/β-CD>β-CD. The flours with carriers were more dispersive and had smoother surface than flour without carrier. The addition of carrier had little effects on flours' sorption isotherm and the Halsey model presents the best goodness-of-fit to all flours. The flour with MD had higher retention rate of anthocyanins, flavonoids and total phenolics than flours without and with other carriers. The flour with MD has higher antioxidant activity (DPPH test) than flours with MD/β-CD or β-CD.