Curcumin as a bioactive component has antioxidant and antibacterial activity which can be used in various nonpolar food and pharmaceutical formulations. In this study, oil-in-water curcumin nanodispersions were prepared using a subcritical water technique. In order to investigate the antioxidant activity and curcumin loss of the prepared nanodispersions, response surface methodology was applied to assess influence of operating conditions including temperature (100–140 °C), and heating time (60–180 min). The results, however, indicated that nanodispersions with minimum curcumin loss (2.65%), maximum antioxidant activity (57.9%) and conductivity (0.36 ms/cm) were produced at optimal operation conditions of 123.03 °C and 112.12 min. The results also indicated that particle size, PDI and zeta-potential values of the provided nanodispersions at optimum conditions were 17.30 nm, 0.260, and − 12.6 mV, respectively. In addition, loading ability and efficiency were 0.194 g/L, and 97.35%, respectively. Furthermore, high antibacterial activity against both Gram-positive and Gram-negative bacteria was achieved at optimum conditions.
