Characterization of Flavoured Olive Oils of ‘Madural’ Variety

Flavoured oils arouse great interest among consumers in many countries due to their variety of flavours and versatility, especially in the culinary field. The aromatization of oils seeks to improve their sensory and nutritional properties, and extend their useful life due to the added substances can be beneficial as antioxidant and antimicrobial agent. In this research, olive oils of the ‘Madural’ variety from Trasos Montes region of Portugal have been obtained and flavoured with different aromatics herbs and condiments (flower of salt and bay leaf, garlic, rosemary and dehydrated lemon peel). The objective is to study the influence of the aromatic herbs and condiments on the physicochemical parameters of the oils: quality, purity, oxidative stability and microbiological analysis. It can be noted that the flavourings do not significantly alter the quality of the monovarietal oil, although, for some parameters, the excessive contact times can affect the category of the oil. On the other hand, the high content of antioxidants provided by flavouring agents can favour its stability and prolong its expiration. In this sense, the flavouring agent that contributes to stop the oxidation of the oil over time is salt + bay leaves, as higher oxidative stability values were detected than those obtained in monovarietal oil. However, oils flavoured with rosemary or lemon show a decrease over time for this parameter, which could indicate that this flavouring accelerates oxidation. In the case of oxidative stability referred to those flavoured with garlic, they present similar values to the monovarietal. The effect exerted by flavourings on the different parameters of the oils is complex, since it is influenced by the method followed and the operating variables established for flavouring.