Influence of roasting olive fruit on the chemical composition and polycyclic aromatic hydrocarbon content of olive oil

Alwana olive oil is a special product of the people from the mountains of Morocco. To produce this oil, prior to the pressing procedure, olives are roasted at up to 130 °C, which leads to the formation of a typical roasty and nutty aroma. It can be expected that this process, which strongly differs from the usual production technic of virgin olive oil, impact the oil chemical composition. We observed that the roasting process has no influence on the fatty acid and sterol composition of Alwana olive. Concentration in α-tocopherol underwent a slight decrease (from 93 to 91%) whereas γ-tocopherol, polyphenol, and chlorophyll content were increased by the roasting process. Polycyclic aromatic hydrocarbon content was found to be 50 µg kg−1.