Comparison of the Chemical Composition and the Organoleptic Profile of Virgin Olive Oil from Two Wild and Two Cultivated Tunisian Olea europaea

With the aim to select new olive cultivars with superior physical and chemical properties than the cultivar Chemlali Sfax, the present study focused on the comparison of the chemical composition and the sensory profile of the virgin olive oils (VOOs) of two wild olive trees (Oleasters K and M) with those of VOOs obtained from Chemlali Sfax and Neb Jmel olive cultivars, all growing in the coastal region of Tunisia. Despite the variability in the chemical composition (fatty acids, pigments, and phenolic and volatile compounds) and the organoleptic profile of the VOOs of the oleasters and the cultivars, the quality indices (free fatty acids, peroxide value, and spectrophotometric indices K232 and K270) as well as the fatty acid composition of all VOOs studied met the commercial standards. Both the alpha-tocopherol and phenol contents varied between the genotypes. The Nab Jmel and Oleaster K VOOs had more than two times higher total phenol levels than the Chemlali Sfax and feaster M VOOs. Also the contents of volatile compounds differed between the olive oils studied. Chemlali Sfax and feaster K oils were more abundant in aldehydes, whereas feaster M VOO had higher contents of alcohols. These results were confirmed by a sensorial analysis showing that the later oil was deprived for consumption despite its abundance in alpha-tocopherol. In conclusion, the oleasters studied revealed to be interesting, since they produced oils with good quality characteristics in terms of minor compounds (phenols and volatiles) compared to the Chemlali Sfax cultivar.