Chemical characterization of a variety of cold-pressed gourmet oils available on the brazilian market
Different specialty extra virgin oils, produced by cold-pressing fruits/nuts (olive, pequi, palm, avocado, coconut,
macadamia and Brazil nut) and seeds (grapeseed and canola), and retailed in the Brazilian region of Minas
Gerais, were chemically characterized. Specifically, for each type of oil, the fatty acid composition was elucidated
by GC-FID, the contents of selected polyphenols and squalene were determined respectively by UHPLC-MS
and UHPLC-PDA, whereas minerals were explored by means of ICP-MS. Olive oil was confirmed to have the
highest MUFA content due to a valuable level of oleic acid, while oils from grapeseed, Brazil nut and canola were
marked by nutritionally important PUFA levels. The highest SFA content found in coconut oil was mainly due to
the high levels of lauric acid, known for its advantageous HDL-raising effects. As for polyphenols, gourmet oils
from palm, coconut and canola showed higher levels of phenolic acids (e.g. p-hydroxybenzoic, ferulic, syringic,
acids) than olive oil, which was though characterized by peculiar antioxidants, such as tyrosol and hydroxytyrosol.
Also, olive oil had the highest amount of squalene, followed by the oil from Brazil nut. Finally, all the
investigated oils had very low levels (order of μg/kg) of pro-oxidant elements, such as Cu, Fe and Mn. Overall,
these findings may fill the gaps still present in literature on certain compositional aspects of commercially
available gourmet oils.