The astaxanthin degradation rate was highest for nanodispersions in deionised water, whereas astaxanthin was comparatively stable in orange juice and skimmed milk. The data in Fig. 1 can be fit by first-order kinetic equations with coefficients of determination (R2) greater than 0.9 (Table 2). The degradation rate of astaxanthin (r) in nanodispersions can therefore be written as: