Análise da eficiência de tecnologias limpas baseadas na espectroscopia no infravermelho e na cromatografia para reconhecimento da qualidade do óleo essencial de Melaleuca.

Abstract

CLEAN TECHNOLOGIES BASED ON INFRARED SPECTROSCOPY TO PREDICT THE QUALITY OF MELALEUCA ESSENTIAL OIL. Quality control of essential oils is carried out mainly by gas chromatography, aiming to identify their chemical composition and detect possible adulterations with synthetic substances or other oils. In this study, thirty-six commercial samples of Melaleuca sp. essential oil were analyzed for their chemical composition and physicochemical properties. Fifteen main components were identified, with Terpinen-4-ol, α-Terpinene, Terpinolene, and p Cymene being the most abundant. For comparative purposes, a control essential oil was extracted by hydrodistillation using the Clevenger method and characterized, along with the commercial samples, by gas chromatography coupled with mass spectrometry (GC MS). The refractive index of the samples was correlated with the results obtained by infrared spectroscopy (FTIR), allowing the identification of adulterated samples through multivariate analysis. Additionally, the optimization of chromatographic analysis of the essential oil directly from Melaleuca sp. leaves was performed using the Headspace technique, enabling the quantification of its major compounds. The results indicate that both spectroscopy, for adulteration detection, and the Headspace technique, for direct leaf analysis, are promising tools for the rapid characterization of essential oil. These approaches prove to be faster, more environmentally responsible, and potentially cleaner alternatives for the quality control of this product. Future studies may focus on the characterization of minor compounds in the oil directly from the leaves and by spectroscopy, as well as improving adulteration quality control using rapid physicochemical methods correlated with spectroscopy.