Physical and oxidative stability of babassu (Orbignya phalerata mart) oil in water nanoemulsions: Effect of oil and guar gum concentrations

Babassu oil (BO) was used in the production of oil in water (O/W) nanoemulsions in order to evaluate the potential application of an alternative source of vegetable oil in the composition of colloidal systems. The proportion of oil phase (10, 20 and 30 % w/w) and guar gum (GG) concentrations (0, 0.10, 0.15 and 0.20 % w/w) were evaluated for 30 days of storage at 5 °C. Physical (pH, viscosity, zeta potential, average diameter, microstructure, and creaming index) and the oxidative stability were measured to evaluate the feasibility of BO in the production of O/W nanoemulsions. The nanoemulsions presented a zeta potential higher than 19.17 mV in absolute value. All systems presented a polydispersity index (PDI) below 0.031 and unimodal size distributions, with the mean droplet diameter size below 246.17 nm. The addition of GG increased the viscosity of the emulsions and the average droplet diameter size. For all samples, creaming index did not vary significantly after 30 days of storage at 5 °C, contributing to the stability of the system. In general, the samples containing a higher oil concentration (30 %) were less stable in terms of oxidation, possibly due to the increased amount of oil. BO can be a promising alternative source of oil to produce nanoemulsions, as the emulsions containing up to 20 % w/w oil and 0.15 % w/w GG presented promising results regarding the physical and oxidative stability. Nanoemulsions with increased stability containing alternative sources of oil may be an interesting approach for cosmetic, pharmaceutical, and food industries.