Avaliação de azeites de oliva extra virgem produzidos no sul de Minas Gerais : parâmetros de qualidade, atividade antioxidante e perfil sensorial

Abstract

In Brazil, the production and consumption of extra virgin olive oils has shown exponential growth, a factor attributed to its nutritional, dietary and differentiated sensory properties, however, studies that evaluate parameters of quality, antioxidant activity and sensorial profile are scarce. In this context, the objective of this work was to evaluate the parameters of quality, antioxidant activity and to characterize the sensorial profile of extra virgin olive oils from different cultivars produced in the south of Minas Gerais. For the evaluation of the quality parameters, physical and chemical analyzes of acidity, peroxide index, refractive index, saponification index, iodine index, ultraviolet specific extinction, density, fatty acid profile and oxidative stability were performed. The levels of pigments (chlorophyll and carotenoids), phenolic compounds and antioxidant activity of olive oils were evaluated in different in vitro models: DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS (2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) and FRAP (Ferric reducing antioxidant power). For the sensory analysis, ten judges trained using Quantitative Descriptive Analysis (DSC) generated the sensory profiles of the samples evaluated, and the results were analyzed through analysis of variance (ANOVA) and comparison of means by the Tukey test at the level of 5% of significance followed by Principal Component Analysis (PCA) by SAS software. The other analyzes were performed in triplicate using Prism 5.0 software (GraphPad). All quality parameters evaluated are in accordance with the Brazilian legislation, demonstrating that the evaluated oils can be classified as extra virgin olive oil. As for the fatty acid profile, oleic acid (C18: 1) was the majority, ranging from 63.86 to 79.24%, followed by palmitic and linoleic acids. As regards the content of pigments (chlorophyll and carotenoids), phenolic compounds and oxidative stability, the Grapollo cultivar sample was highlighted. Regarding the analyzes of the antioxidant activity, only the DPPH radical sequestration method. allowed to identify statistical difference among the samples. In general, the sensorial profiles of the cultivars Frantoio, Mission and Grapollo were characterized by positive attributes of green, bitter and spicy olive. The production of olive oils in Brazil presents promising results from the point of view of quality standards, chemical composition, antioxidant activity and sensorial profile.