Análise da permeação de óleos em cabelo humano utilizando Espectroscopia Raman confocal.

Abstract

With the different forms of hair treatments that exist today, hair suffers a lot of damage from physical and chemical procedures. So the challenge is to find oils that better permeate the hair fiber up to the inner layer, allowing protection against the aggressions promoted, as natural lipids have a protective function. Copaiba oil is a mixture of light and heavy terpenes and medium-chain fatty acids, which acts as a shine-giving agent and hair recovery agent. Andiroba oil is composed of triglycerides and saturated, monounsaturated and unsaturated fatty acids and coconut oil is composed of saturated fatty acids, giving it great potential to penetrate the hair fiber. The Raman spectroscopy technique allows identifying, with high resolution and specificity, the depth and concentration with which the oils penetrate the fiber. The study aimed to analyze the permeation of copaíba, andiroba and coconut oils in the hair fiber in human hair using the confocal Raman spectroscopy technique. Five untreated hair fibers were considered as control (CTR) and five treated fibers (TTD) for each oil tested. The treatment consisted of depositing 10 µl of the test oil on the five fibers (TTD). Raman spectra were collected before and after 30 minutes of treatment with the oils, from the surface to a depth of 40 µm, corresponding to the cuticle, cortex and medulla every 2 µm. Data pre-processing was done by removing fluorescence, followed by smoothing (Savitzky-Golay filter, grade 5) and vector normalization. After processing the data, the biochemical characterization of the oils was carried out, the marker peaks were identified and, through the calculation of the area under the curve, the permeation profile of each oil was detected. Quantification of the concentration of permeated oil showed proximity between the permeation of copaíba oil (30.14 a.u.) and coconut oil (27.85 a.u.), however, andiroba oil, despite permeating to the deepest layer (medulla), the concentration was lower (14. 09 a.u.) in relation to other oils. This study demonstrated the efficiency of copaíba, coconut and andiroba oils with regard to permeation in hair fibers, generating information for the development of products capable of permeating even the innermost layer of hair fibers, thus providing recovery of damaged hair, ensuring a healthy hair fiber.