Composição química e estabilidade térmica de azeite de oliva (Olea europaea L.) produzido em Canguçu-RS

Abstract

The aim of this study was to evaluate the chemical composition of three olive oil samples (Arbequina, Arbosana and Koroneiki) produced in Canguçu (RS), and to evaluate the chemical stability of one of the olive oils(Koroneiki) submitted to heating (60, 100, 120, 150 and 180°C) for a period of two hours (0, 10, 20, 40, 60, 80, 100 and 120 minutes). The samples of cultivar Koroneiki were placed in glass containers, which were taken to anoven without air circulation, and at predetermined periods (0, 10, 20, 40, 60, 80 and 120 minutes) samples were removed and analyzed for peroxide value and acidity, carotenoids, chlorophylls, phenolic compounds and tocopherols. It was observed that the increase in temperature and heating time considerably affected the quality parameters of the oil sample subjected to heating, with increases in acidity, decrease in the peroxide value, and considerable losses were evidenced in the content of carotenoids, chlorophylls, phenolic compounds and tocopherols. The results indicate that exposing the samples to heating accelerates the hydrolysis and oxidation process, producing losses in the quality of the olive oil. These data contribute information on oils from the cultivation of southern Brazil, emphasizing that heating changes the thermal stability of the oil and that when using it for culinary purposes for heating food and being exposed to long periods of time, it occurs a significant degradation of bioactive compounds, such as carotenoids, phenolic compounds and tocopherols.