Introduction: The search of consumers for cosmetics based on natural raw materials has increased over the years, as well as the investment to prospect new ingredients and the development of sustainable formulations. In this scenario, Brazilian biodiversity has potential for application in the development of innovative cosmetic products. The oil extracted from the Caryocar brasiliense Cambess, also known as pequi oil, native to the Brazilian Cerrado is well known for its antioxidant and anti-inflammatory due to its rich composition of secondary metabolites like polyphenols and carotenoids and primary ones like oleic and palmitic acid. Thus, it has potential for application in the development of cosmetics formulations for skin and hair care. The incorporation of this natural oil in cosmetic formulations could bring benefits for skin, such as the increase of the hydration, protection of skin barrier function and antioxidant effects. In this context, the proposal of this study was to develop a minimalist cosmetic formulation containing the pequi oil and to evaluate the rheological behavior, texture profile and sensory properties.

Methods: A gel cream formulation added or not (vehicle) to 5% of pequi oil was developed. determination and centrifugation for 28 days. In the study of rheological behavior, texture and spreadability analyses, the formulations were evaluated regarding flow index, consistency, viscosity, firmness, cohesiveness, index of viscosity and work of shear. The sensory properties were evaluated in 16 participants, who answered a questionnaire about their perception immediately after the application of these two formulations, regarding the spreadability and smoothness sensation, and after 5 minutes application they evaluated the hydration sensation, stickiness touch and white residue.

Results and discussion: The obtained results showed that developed formulations were stable in the preliminary tests of pH and centrifugation during 28 days of study. Besides, the formulations presented thixotropic and pseudoplastic rheological behavior and the rheograms not showed peak formation or changes during shear after 14 and 28-day period of the study. The results of texture profile evaluation showed that the addition of the pequi oil significantly reduces the parameters of consistency, firmness, cohesiveness, and index of viscosity, due the action of the oil as an emollient, which interacts with the microstructure of the formulation, making the formulation less consistent. However, the work of shear parameter did not change between the vehicle and the formulation added with the pequi oil, which suggests that the presence of the oil did not compromise the spreadability of the formulation. The presence of oils in the composition of cosmetic products usually are known for the oily sensation that the formulations leave on the skin. Although, in the sensorial analysis the formulation added to pequi oil presented a good spreadability and increased the sensation of hydration, with no white residue or stickiness touch. The use of this natural ingredient can promote the increase of the sensorial properties, promoting a soft touch and smoothness sensation during the formulation application.
Conclusion: The use of the pequi oil showed stability after 28 days of analysis and a thixotropic and pseudoplastic rheological behavior. The properties of the texture profile showed that the presence of pequi oil did not influence in the work of shear, which directly reflects on the sensorial performance. In addition, the formulation added with pequi oil did not change sensorial properties, showing a good spreadability, no oily residue and the study participants perceived the moisturizing effect. Thus, the pequi oil is an effective natural ingredient from Brazilian biodiversity to be applied in the cosmetic products since it can bring important benefits for a skin care formulation, such as an improvement of sensorial properties and skin hydration.